Add experimental HTML/CSS "modern" render style for weather widget

The weather widget's icons/layout are hand-drawn PIL primitives -- clean
under quantization but flat, no gradients/shadows. Adds an opt-in
render_style="modern" (current/daily modes only) that instead renders a
Jinja2 template through a persistent headless-Chromium browser
(app/html_render.py), following the approach of Tesserae, an open-source
e-ink dashboard targeting this same panel family.

Key design points:
- The Chromium dependency (Playwright) is lazily imported only when a
  weather widget actually uses "modern" style, and the background browser
  itself only launches on first use -- every other widget type, and this
  one's own classic/hourly/multi_city paths, never pay for it.
- No Frame-level dithering setting needed: html_render dithers its own
  rendered widget to exact palette colors (Bayer/ordered, not
  Floyd-Steinberg) before compositing, so the shared whole-canvas
  Floyd-Steinberg pass sees zero quantization error there and leaves it
  untouched -- same trick draw_text/hand-drawn icons already use. Floyd-
  Steinberg keeps working unchanged for photos and every other widget.
- A "Load calibrated Spectra 6 preset" button in Advanced configuration
  offers a community-measured palette (data ported from
  paperlesspaper/epdoptimize, Apache 2.0) as an alternative starting
  point to the existing idealized DEFAULT_PALETTE_RGB -- fills the
  existing palette table, doesn't save by itself.

Known open risk, not resolved here: a headless Chromium binary is far
larger than the ~100MB single-layer limit that already forced this
project's pip/npm installs into split layers, and (unlike those) is a
single ~180MB file that can't be split across layers by ordinary
Dockerfile restructuring. Flagged prominently in server/Dockerfile and
docs/widgets.md -- treat this render style as experimental/local-only
until that's resolved.

.claude/skills/make-widget/SKILL.md

@@ -1,6 +1,6 @@
 ---
 name: make-widget
-description: Scaffold a new widget type for the espresso_frame server (the ~13-file checklist a widget type touches -- config table, grid footprint, render module, registry, migration, config-save + endpoints, dialog template + JS, script tag, WIDGET_LABELS, docs, tests). Use when asked to add a new widget type to a frame's panel (e.g. "add a text widget", "add an RSS widget", "add a weather-only widget").
+description: Scaffold a new widget type for the espresso_frame server (the ~14-file checklist a widget type touches -- config table, grid footprint, render module, registry, migration, config-save + endpoints, dialog template + JS, script tag, WIDGET_LABELS, docs, saved-layout config allowlist, tests). Use when asked to add a new widget type to a frame's panel (e.g. "add a text widget", "add an RSS widget", "add a weather-only widget").
 ---
 
 Adding a widget type is a very consistent, repeated pattern in this
@@ -114,6 +114,16 @@ Pick your template accordingly:
     `MIN_FOOTPRINT` prose line, the `app/widgets/` module list. This is
     the project's own "start here" doc per `CLAUDE.md` -- don't ship a
     widget without it staying accurate.
+14. **`app/routers/api_layouts.py`** -- add a `"<type>": (...)` entry to
+    `LAYOUT_CONFIG_FIELDS` listing the config columns that are an
+    authored *setting* (as opposed to runtime/cache state like a fetch
+    cache or queue position, which a saved layout deliberately leaves
+    out -- see the dict's own comment). Skipping this doesn't error or
+    warn anywhere: the widget just silently saves/applies with an empty
+    `{}` config forever, resetting to defaults on every layout apply or
+    hold-to-cycle. This actually shipped missing for the weather widget
+    -- caught only because a user noticed layout-cycling kept resetting
+    its city/mode.
 
 ## Tests (`server/tests/`)
 
@@ -138,6 +148,13 @@ Pick your template accordingly:
 - Any pure-logic helper module (decoding, parsing -- like
   `app/image_upload.py`) gets its own `test_<module>.py`: no HTTP, no
   DB, just the function.
+- `test_saved_layouts.py` -- a `test_save_and_apply_round_trip_<type>_settings`
+  test: set every field the new `LAYOUT_CONFIG_FIELDS` entry lists,
+  save a layout, assert the `SavedLayoutWidget.config` snapshot has them
+  all, delete the frame's widgets, apply the layout back, assert the
+  new widget's config matches -- and that any runtime/cache field
+  (`checked_at`, a fetch cache, a queue) was *not* carried over. See
+  `test_save_and_apply_round_trip_weather_settings` for the pattern.
 
 Run the full suite before calling it done:
 

docs/widgets.md

@@ -269,6 +269,25 @@ modes (`WeatherWidgetConfig.mode`, switchable in the widget's dialog like
   side -- the calendar widget's embedded strip, as a standalone
   widget's whole content instead of a strip above an agenda day.
 
+**Render style** (`WeatherWidgetConfig.render_style`, `"classic"` default
+| `"modern"`, experimental): `current`/`daily` only -- `hourly`/
+`multi_city` always render classic regardless of this setting. `modern`
+draws the widget as an HTML/CSS card (Jinja2 templates under
+`app/templates/widget_html/`) through a persistent headless Chromium
+browser (`app/html_render.py`, Playwright) instead of `app/weather_render.
+py`'s hand-drawn PIL primitives -- gradients/shadows/soft icon shading
+PIL can't easily do. Its own `ordered_dither` (Bayer/ordered, not Floyd-
+Steinberg) commits the rendered widget to exact palette colors *before*
+compositing, so it's safe to mix with photo/other classic-rendered
+widgets on the same frame without a Floyd-Steinberg seam at the boundary
+(see that module's docstring for why ordered dithering doesn't have this
+problem and Floyd-Steinberg does) -- no `Frame`-level dithering setting
+was needed. Playwright/Chromium is a real, heavyweight runtime dependency
+imported lazily only when a weather widget actually uses this style, and
+its Docker packaging has a known likely-blocking image-size problem not
+yet resolved (see `server/Dockerfile`'s own comment) -- treat this style
+as unshipped/local-only until that's sorted out.
+
 `current`/`hourly`/`daily` share one configured location
 (`city_label`/`city_latitude`/`city_longitude`, set via `POST .../
 weather-location`, geocoded through `weather.geocode_city`); `multi_city`

server/Dockerfile

@@ -36,25 +36,62 @@ RUN apt-get update && apt-get install -y --no-install-recommends \
     tzdata fontconfig fonts-dejavu-core nodejs npm \
     && rm -rf /var/lib/apt/lists/*
 
+# EXPERIMENTAL, likely unmergeable as-is -- see below. System libs a
+# headless Chromium needs (app/html_render.py, the weather widget's
+# opt-in "modern" render style), trimmed from Playwright's own full
+# `install-deps chromium` list to just what a headless (no Xvfb),
+# Latin-text-plus-emoji use case needs: dropped xvfb (only needed for a
+# *headed* browser) and the CJK/Cyrillic/Thai locale font packages
+# (fonts-ipafont-gothic, fonts-wqy-zenhei, fonts-tlwg-loma-otf,
+# xfonts-cyrillic, xfonts-scalable, fonts-freefont-ttf, fonts-unifont) --
+# fonts-noto-color-emoji is the one that actually matters here (real
+# color emoji in the weather icons, vs. WeasyPrint/Pango's monochrome
+# fallback glyphs in this feature's original spike).
+RUN apt-get update && apt-get install -y --no-install-recommends \
+    libasound2t64 libatk-bridge2.0-0t64 libatk1.0-0t64 libatspi2.0-0t64 \
+    libcairo2 libcups2t64 libdbus-1-3 libdrm2 libgbm1 libglib2.0-0t64 \
+    libnspr4 libnss3 libpango-1.0-0 libx11-6 libxcb1 libxcomposite1 \
+    libxdamage1 libxext6 libxfixes3 libxkbcommon0 libxrandr2 \
+    fonts-noto-color-emoji libfontconfig1 libfreetype6 fonts-liberation \
+    && rm -rf /var/lib/apt/lists/*
+
 COPY requirements.txt .
 # Split across several layers rather than one `pip install -r
 # requirements.txt` -- same Cloudflare single-blob/layer payload-size
 # limit as render-service's npm installs below. The single combined
 # layer was measured at ~113MB unpacked, over the limit on its own.
-# Isolating the three largest packages gets every layer's unpacked size
-# well clear of 100MB (sqlalchemy ~15MB, pillow ~19MB, pypdfium2 ~8MB,
-# the remaining `-r requirements.txt` layer ~71MB). Each package
-# version here still comes from requirements.txt (`pip install -r` for
-# everything that doesn't need its own layer skips these three, since
-# pip sees them already satisfied); the explicit versions below just
-# control *when* each installs -- same "single source of truth, just
-# splitting *when* it installs" tradeoff as the npm section's --no-save
-# comment below.
+# Isolating the largest packages gets every layer's unpacked size well
+# clear of 100MB (sqlalchemy ~15MB, pillow ~19MB, pypdfium2 ~8MB, the
+# remaining `-r requirements.txt` layer ~71MB). Each package version here
+# still comes from requirements.txt (`pip install -r` for everything that
+# doesn't need its own layer skips these, since pip sees them already
+# satisfied); the explicit versions below just control *when* each
+# installs -- same "single source of truth, just splitting *when* it
+# installs" tradeoff as the npm section's --no-save comment below.
 RUN pip install --no-cache-dir sqlalchemy==2.0.51
 RUN pip install --no-cache-dir pillow==12.3.0
 RUN pip install --no-cache-dir pypdfium2==5.12.1
+RUN pip install --no-cache-dir playwright==1.61.0
 RUN pip install --no-cache-dir -r requirements.txt
 
+# KNOWN LIKELY BLOCKER, not resolved by pulling this into its own layer:
+# `playwright install chromium-headless-shell` unpacks to ~262MB, and its
+# single `chrome-headless-shell` binary alone (measured: 181MB) is one
+# file -- unlike the pip/npm splits above (independently-installable
+# smaller packages moved into their own layers), a single 181MB file
+# can't be divided across multiple <100MB Docker layers by any ordinary
+# COPY/RUN restructuring; the whole file lands in whichever layer's diff
+# contains it. This almost certainly exceeds the same Cloudflare single-
+# blob/layer limit that forced the pip/npm splits elsewhere in this file
+# (see their comments) -- an actual push to this project's registry
+# hasn't been attempted (would require pushing to `main`, which triggers
+# deploy) to confirm, but there is no reason to expect a single 181MB
+# blob to fit where combined ~113MB of many small wheels didn't. Needs a
+# real resolution (a registry without this limit, hosting the browser
+# binary outside the image, etc.) before this branch can actually ship --
+# tracked as open, not silently assumed away.
+RUN playwright install chromium-headless-shell
+
 # render-service/'s dependencies installed as several separate layers
 # rather than one `npm install` covering all of them -- a from-scratch
 # push of this image once hit Cloudflare's payload-size limit on a

server/app/calendar_render.py

@@ -11,7 +11,7 @@ Event dicts here are calendar_feed.py's shape: {"summary", "start", "end"
 (ISO 8601 strings), "all_day", "sources": [{"owner_display_name",
 "color_index"}, ...]} -- more than one entry in "sources" means
 merge_events collapsed several calendars' identical (same title/time)
-events into one, see _event_colors/_draw_color_bar below.
+events into one, see _event_colors/panel_style.draw_color_chip below.
 """
 
 from __future__ import annotations
@@ -26,6 +26,7 @@ from zoneinfo import ZoneInfo
 
 from PIL import Image, ImageDraw, ImageFont
 
+from . import panel_style
 from .image_pipeline import (
     DEFAULT_PALETTE_RGB,
     _apply_manage_overlay,
@@ -42,12 +43,20 @@ CALENDAR_VIEW_LABELS = {"agenda": "Agenda (today)", "today_tomorrow": "Agenda (t
                         "week": "Week", "month": "Month"}
 WEEKDAY_NAMES = ["Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday", "Sunday"]
 
-MARGIN = 20
+# MARGIN carries panel_style.CONTENT_MARGIN's value unchanged (not
+# re-tuned). BG/FG are this module's own plain black/white -- checkbox
+# outlines, month-view grid hairlines -- not a text-emphasis concern (no
+# MUTED gray here anymore -- see panel_style's module docstring for why:
+# a mid-gray fill has no close palette match and dithers into speckle
+# once the whole canvas is quantized. Secondary text now reads through
+# size/weight alone, always exact black).
+MARGIN = panel_style.CONTENT_MARGIN
 BG = (255, 255, 255)
 FG = (0, 0, 0)
-MUTED = (110, 110, 110)
-# Was a light gray, but that dithers away to near-invisible once quantized
-# to the 6-color e-ink palette -- black reads as an actual line on-panel.
+# Structural dividers/grid lines (between stacked day sections, week
+# columns, month cells) stay a plain black rule -- gray dithers away to
+# near-invisible once quantized to the 6-color e-ink palette. Headers
+# no longer use this: see panel_style.draw_header_bar/theme_color.
 RULE = (0, 0, 0)
 
 # Fallback for any event whose calendar has no manually pinned color
@@ -67,7 +76,7 @@ def _event_colors(event: dict, owners_seen: list[str], palette_rgb: list | None)
     one person's calendar). Usually just one color; more than one is
     what tells the "same event, more than one calendar" case apart from
     an ordinary single-calendar event at render time -- see
-    _draw_color_bar. Each source's own manually pinned color
+    panel_style.draw_color_chip. Each source's own manually pinned color
     (FrameCalendar.color_index -- see routers/api_widgets.py's
     api_widget_calendar_color) resolves against whichever palette this frame
     actually renders with, so a pinned "Blue" stays this frame's actual
@@ -91,24 +100,6 @@ def _event_colors(event: dict, owners_seen: list[str], palette_rgb: list | None)
     return colors
 
 
-def _draw_color_bar(draw: ImageDraw.ImageDraw, x0: int, y0: int, x1: int, y1: int,
-                    colors: list[tuple[int, int, int]], radius: int) -> None:
-    """One rounded bar for a single-source event, or that same overall
-    footprint split into equal-width side-by-side segments -- one per
-    contributing calendar -- for a deduplicated shared event (see
-    _event_colors/calendar_feed.merge_events). Splitting rather than
-    e.g. concentric rings keeps every color equally "thick and bold" at
-    a glance, the same design goal a single pinned color already has."""
-    if len(colors) == 1:
-        draw.rounded_rectangle([x0, y0, x1, y1], radius=radius, fill=colors[0])
-        return
-    seg_w = (x1 - x0) / len(colors)
-    for i, color in enumerate(colors):
-        seg_x0 = round(x0 + i * seg_w)
-        seg_x1 = round(x0 + (i + 1) * seg_w) - (2 if i < len(colors) - 1 else 0)
-        draw.rectangle([seg_x0, y0, seg_x1, y1], fill=color)
-
-
 def _event_start(event: dict, tz: ZoneInfo) -> datetime | date:
     """Parses event["start"] and, for timed events, converts to `tz` --
     calendar_feed.py stores whatever timezone each source event carried
@@ -158,11 +149,12 @@ def _fmt_task_due(due: str | None) -> str:
     return d.strftime("%b %-d")
 
 
-# ImageFont.load_default() (used for everything else in this module --
-# see the module docstring) has no emoji glyphs, and PIL/FreeType don't
-# skip an unsupported codepoint, they substitute a ".notdef" tofu box (a
-# visible filled rectangle) -- reads as a rendering glitch, not "emoji
-# not supported". So event titles get drawn with two fonts: the normal
+# Neither Inter (panel_style.font_bold/font_regular, this module's own
+# body/title font -- see MARGIN/BG/FG comment above) nor PIL's bundled
+# default font has emoji glyphs, and PIL/FreeType don't skip an
+# unsupported codepoint, they substitute a ".notdef" tofu box (a visible
+# filled rectangle) -- reads as a rendering glitch, not "emoji not
+# supported". So event titles get drawn with two fonts: the normal
 # text font for everything else, and one of these for actual emoji runs
 # (see _split_emoji_runs/_draw_mixed_line) -- both Noto Emoji, OFL-1.1,
 # vendored at app/fonts/ (license alongside at app/fonts/OFL.txt).
@@ -401,15 +393,17 @@ def _draw_agenda_day(img: Image.Image, draw: ImageDraw.ImageDraw, day: date, eve
     these vertically without duplicating the row-layout/truncation
     logic. Weather is drawn above the event list -- eating into the same
     row budget the event count is truncated against, exactly like the
-    header/rule above it already does."""
+    header bar above it already does."""
     x0, y0, w, h = region
-    text_x0, text_y0 = x0 + MARGIN, y0 + MARGIN
+    header_h = title_font.size + 20
+    panel_style.draw_header_bar(draw, (x0, y0, w, header_h), header_h,
+                                panel_style.theme_color("calendar", palette_rgb))
+    text_x0 = x0 + MARGIN
     text_w = w - MARGIN * 2
     header = day.strftime("%A, %B ") + str(day.day)
-    draw_text(img, (text_x0, text_y0), _truncate_to_width(draw, header, title_font, text_w), title_font)
-    y = text_y0 + title_font.size + 12
-    draw.line([(text_x0, y), (text_x0 + text_w, y)], fill=RULE)
-    y += 12
+    draw_text(img, (text_x0, y0 + (header_h - title_font.size) // 2),
+             _truncate_to_width(draw, header, title_font, text_w), title_font, BG)
+    y = y0 + header_h + 12
 
     weather_entries = _weather_for_day(weather_cities, day)
     if weather_entries:
@@ -422,13 +416,13 @@ def _draw_agenda_day(img: Image.Image, draw: ImageDraw.ImageDraw, day: date, eve
     max_rows = max(0, (y0 + h - MARGIN - y) // row_h)
 
     if not day_events:
-        draw_text(img, (text_x0, y), "Nothing scheduled", body_font, MUTED)
+        draw_text(img, (text_x0, y), "Nothing scheduled", body_font)
     for i, event in enumerate(day_events):
         if i >= max_rows:
-            draw_text(img, (text_x0, y), f"+{len(day_events) - max_rows} more", body_font, MUTED)
+            draw_text(img, (text_x0, y), f"+{len(day_events) - max_rows} more", body_font)
             break
         colors = _event_colors(event, owners_seen, palette_rgb)
-        _draw_color_bar(draw, text_x0, y + 2, text_x0 + 10, y + row_h - 7, colors, radius=3)
+        panel_style.draw_color_chip(draw, text_x0, y + 2, text_x0 + 10, y + row_h - 7, colors)
         time_str = "All day" if event["all_day"] else _fmt_time(_event_start(event, tz))
         prefix = f"{time_str}  "
         draw_text(img, (text_x0 + 18, y), prefix, body_font)
@@ -445,13 +439,13 @@ def _draw_tasks(img: Image.Image, draw: ImageDraw.ImageDraw, region: tuple[int,
     (`title`, truncated to fit -- TaskWidgetConfig.name or the "Tasks"
     default; the only widget type with its own on-panel title, since
     it's the only one where "which list is this" isn't obvious from its
-    content the way a calendar/photo/whiteboard's is), then a color bar
-    (reusing _event_colors/_draw_color_bar as-is: a task dict's
-    top-level owner_display_name/color_index is exactly _event_colors'
-    single-source fallback shape, since caldav_client.merge_tasks
-    doesn't cross-list-dedup tasks into a "sources" list the way
-    merge_events dedups events) + checkbox glyph + due date (if any) +
-    summary per task, same header/rule/row-cap/truncation shape as
+    content the way a calendar/photo/whiteboard's is), then a color chip
+    (reusing _event_colors/panel_style.draw_color_chip as-is: a task
+    dict's top-level owner_display_name/color_index is exactly
+    _event_colors' single-source fallback shape, since caldav_client.
+    merge_tasks doesn't cross-list-dedup tasks into a "sources" list the
+    way merge_events dedups events) + checkbox glyph + due date (if any)
+    + summary per task, same header/row-cap/truncation shape as
     _draw_agenda_day's event list so the standalone tasks widget (see
     _build_tasks) reads as the same consistent design as everything
     else on-panel, not a bolted-together look. Reuses _draw_mixed_line
@@ -460,45 +454,52 @@ def _draw_tasks(img: Image.Image, draw: ImageDraw.ImageDraw, region: tuple[int,
 
     Outstanding tasks get an empty checkbox; completed ones (only ever
     present when TaskWidgetConfig.show_completed is on -- see
-    caldav_client.fetch_tasks' completed_since) get a filled one and
-    muted text, no due-date prefix (irrelevant once done)."""
+    caldav_client.fetch_tasks' completed_since) get a filled checkbox in
+    this widget's own Green accent (see panel_style.THEME) -- that fill
+    is the "done" signal, no due-date prefix (irrelevant once done) and
+    no separate muted text treatment (see module-level MUTED removal
+    note above _event_colors)."""
     x0, y0, w, h = region
-    text_x0, text_y0 = x0 + MARGIN, y0 + MARGIN
+    header_h = title_font.size + 20
+    panel_style.draw_header_bar(draw, (x0, y0, w, header_h), header_h,
+                                panel_style.theme_color("tasks", palette_rgb))
+    text_x0 = x0 + MARGIN
     text_w = w - MARGIN * 2
-    draw_text(img, (text_x0, text_y0), _truncate_to_width(draw, title or "Tasks", title_font, text_w), title_font)
-    y = text_y0 + title_font.size + 12
-    draw.line([(text_x0, y), (text_x0 + text_w, y)], fill=RULE)
-    y += 12
+    draw_text(img, (text_x0, y0 + (header_h - title_font.size) // 2),
+             _truncate_to_width(draw, title or "Tasks", title_font, text_w), title_font, BG)
+    y = y0 + header_h + 12
 
     row_h = body_font.size + 14
     max_rows = max(0, (y0 + h - MARGIN - y) // row_h)
 
     if not tasks:
-        draw_text(img, (text_x0, y), "Nothing outstanding", body_font, MUTED)
+        draw_text(img, (text_x0, y), "Nothing outstanding", body_font)
         return
     owners_seen: list[str] = []
+    checkbox_fill = panel_style.theme_color("tasks", palette_rgb)
     for i, task in enumerate(tasks):
         if i >= max_rows:
-            draw_text(img, (text_x0, y), f"+{len(tasks) - max_rows} more", body_font, MUTED)
+            draw_text(img, (text_x0, y), f"+{len(tasks) - max_rows} more", body_font)
             break
         done = task.get("completed_at") is not None
         colors = _event_colors(task, owners_seen, palette_rgb)
-        _draw_color_bar(draw, text_x0, y + 2, text_x0 + 10, y + row_h - 7, colors, radius=3)
+        panel_style.draw_color_chip(draw, text_x0, y + 2, text_x0 + 10, y + row_h - 7, colors)
         box = body_font.size - 6
         box_x = text_x0 + 18
         box_y = y + (row_h - box) // 2 - 5
+        box_r = min(panel_style.CHIP_RADIUS, box // 2)
         if done:
-            draw.rectangle([box_x, box_y, box_x + box, box_y + box], fill=FG)
+            draw.rounded_rectangle([box_x, box_y, box_x + box, box_y + box], radius=box_r, fill=checkbox_fill)
         else:
-            draw.rectangle([box_x, box_y, box_x + box, box_y + box], outline=FG, width=2)
+            draw.rounded_rectangle([box_x, box_y, box_x + box, box_y + box], radius=box_r, outline=FG, width=2)
         text_x = box_x + box + 10
         due_str = None if done else _fmt_task_due(task.get("due"))
         prefix = f"{due_str}  " if due_str else ""
         if prefix:
-            draw_text(img, (text_x, y), prefix, body_font, MUTED)
+            draw_text(img, (text_x, y), prefix, body_font)
         prefix_w = draw.textlength(prefix, font=body_font) if prefix else 0
         _draw_mixed_line(img, draw, (round(text_x + prefix_w), y), task["summary"],
-                         body_font, text_w - (text_x - text_x0) - prefix_w, fill=MUTED if done else FG)
+                         body_font, text_w - (text_x - text_x0) - prefix_w)
         y += row_h
 
 
@@ -512,17 +513,16 @@ _AGENDA_FONTS = {"large": (34, 22, 20), "medium": (24, 22, 16), "small": (18, 16
 def _build_agenda(events: list[dict], browse_offset: int, target_w: int, target_h: int, tz: ZoneInfo,
                   palette_rgb: list | None = None, weather_cities: list[dict] | None = None,
                   weather_units: str = "fahrenheit") -> Image.Image:
-    img = Image.new("RGB", (target_w, target_h), BG)
-    draw = ImageDraw.Draw(img)
+    img, draw, region = panel_style.card_canvas(target_w, target_h)
 
     title_size, body_size, weather_size = _AGENDA_FONTS[_size_tier(target_w, target_h)]
-    title_font = ImageFont.load_default(size=title_size)
-    body_font = ImageFont.load_default(size=body_size)
-    weather_font = ImageFont.load_default(size=weather_size)
+    title_font = panel_style.font_bold(title_size)
+    body_font = panel_style.font_regular(body_size)
+    weather_font = panel_style.font_regular(weather_size)
 
     day = datetime.now(tz).date() + timedelta(days=browse_offset)
     owners_seen: list[str] = []
-    _draw_agenda_day(img, draw, day, events, tz, (0, 0, target_w, target_h), title_font, body_font, owners_seen,
+    _draw_agenda_day(img, draw, day, events, tz, region, title_font, body_font, owners_seen,
                      palette_rgb, weather_cities, weather_font, weather_units)
 
     return img
@@ -540,23 +540,22 @@ def _build_today_tomorrow(events: list[dict], browse_offset: int, target_w: int,
     shifts the whole two-day window together, same "days" unit
     _build_agenda already uses, so NEXT/BACK behaves identically across
     both views."""
-    img = Image.new("RGB", (target_w, target_h), BG)
-    draw = ImageDraw.Draw(img)
+    img, draw, (cx0, cy0, cw, ch) = panel_style.card_canvas(target_w, target_h)
 
     title_size, body_size, weather_size = _TODAY_TOMORROW_FONTS[_size_tier(target_w, target_h)]
-    title_font = ImageFont.load_default(size=title_size)
-    body_font = ImageFont.load_default(size=body_size)
-    weather_font = ImageFont.load_default(size=weather_size)
+    title_font = panel_style.font_bold(title_size)
+    body_font = panel_style.font_regular(body_size)
+    weather_font = panel_style.font_regular(weather_size)
 
     start_day = datetime.now(tz).date() + timedelta(days=browse_offset)
-    section_h = target_h // 2
+    section_h = ch // 2
     owners_seen: list[str] = []
     for i in range(2):
-        section_y0 = i * section_h
+        section_y0 = cy0 + i * section_h
         if i > 0:
-            draw.line([(MARGIN, section_y0), (target_w - MARGIN, section_y0)], fill=RULE)
+            draw.line([(cx0 + MARGIN, section_y0), (cx0 + cw - MARGIN, section_y0)], fill=RULE)
         _draw_agenda_day(img, draw, start_day + timedelta(days=i), events, tz,
-                         (0, section_y0, target_w, section_h), title_font, body_font, owners_seen,
+                         (cx0, section_y0, cw, section_h), title_font, body_font, owners_seen,
                          palette_rgb, weather_cities, weather_font, weather_units)
 
     return img
@@ -585,8 +584,7 @@ def _build_week(events: list[dict], browse_offset: int, target_w: int, target_h:
     otherwise "start of the week" doesn't mean much for an arbitrary day
     count, so it instead starts `start_offset` days from today (0 =
     today, see routers/api_widgets.py's api_widget_config_save)."""
-    img = Image.new("RGB", (target_w, target_h), BG)
-    draw = ImageDraw.Draw(img)
+    img, draw, (cx0, cy0, cw, ch) = panel_style.card_canvas(target_w, target_h)
     tier = _size_tier(target_w, target_h)
 
     today = datetime.now(tz).date()
@@ -599,36 +597,36 @@ def _build_week(events: list[dict], browse_offset: int, target_w: int, target_h:
 
     if layout == "vertical":
         title_base, body_base, weather_base = _WEEK_VERTICAL_FONTS[tier]
-        title_font = ImageFont.load_default(size=max(14, title_base - days))
-        body_font = ImageFont.load_default(size=max(11, body_base - days))
-        weather_font = ImageFont.load_default(size=max(9, weather_base - days))
-        section_h = target_h // days
+        title_font = panel_style.font_bold(max(14, title_base - days))
+        body_font = panel_style.font_regular(max(11, body_base - days))
+        weather_font = panel_style.font_regular(max(9, weather_base - days))
+        section_h = ch // days
         for i in range(days):
-            section_y0 = i * section_h
+            section_y0 = cy0 + i * section_h
             if i > 0:
-                draw.line([(MARGIN, section_y0), (target_w - MARGIN, section_y0)], fill=RULE)
+                draw.line([(cx0 + MARGIN, section_y0), (cx0 + cw - MARGIN, section_y0)], fill=RULE)
             day = week_first_day + timedelta(days=i)
-            _draw_agenda_day(img, draw, day, events, tz, (0, section_y0, target_w, section_h),
+            _draw_agenda_day(img, draw, day, events, tz, (cx0, section_y0, cw, section_h),
                              title_font, body_font, owners_seen, palette_rgb,
                              weather_cities, weather_font, weather_units)
         return img
 
     header_size, chip_size, weather_size = _WEEK_HORIZONTAL_FONTS[tier]
-    header_font = ImageFont.load_default(size=header_size)
-    chip_font = ImageFont.load_default(size=chip_size)
-    weather_font = ImageFont.load_default(size=weather_size)
-    col_w = (target_w - MARGIN * 2) // days
+    header_font = panel_style.font_bold(header_size)
+    chip_font = panel_style.font_regular(chip_size)
+    weather_font = panel_style.font_regular(weather_size)
+    col_w = (cw - MARGIN * 2) // days
     header_h = 44
 
     for col in range(days):
         day = week_first_day + timedelta(days=col)
-        x0 = MARGIN + col * col_w
+        x0 = cx0 + MARGIN + col * col_w
         if col > 0:
-            draw.line([(x0, MARGIN), (x0, target_h - MARGIN)], fill=RULE)
+            draw.line([(x0, cy0 + MARGIN), (x0, cy0 + ch - MARGIN)], fill=RULE)
         label = day.strftime("%a %-d") if day != today else f"* {day.strftime('%a %-d')}"
-        draw_text(img, (x0 + 6, MARGIN), _truncate_to_width(draw, label, header_font, col_w - 10), header_font)
+        draw_text(img, (x0 + 6, cy0 + MARGIN), _truncate_to_width(draw, label, header_font, col_w - 10), header_font)
 
-        y = MARGIN + header_h
+        y = cy0 + MARGIN + header_h
         # Columns are narrow, so only what actually fits gets drawn (see
         # weather_render.draw_weather_row) -- typically one city, no label
         # (the column itself makes which day it's for obvious; a city name
@@ -640,14 +638,14 @@ def _build_week(events: list[dict], browse_offset: int, target_w: int, target_h:
                                   icon_r=8, font=weather_font, units=weather_units, show_labels=False,
                                   palette_rgb=palette_rgb)
         row_h = chip_font.size + 10
-        max_rows = max(0, (target_h - MARGIN - y) // row_h)
+        max_rows = max(0, (cy0 + ch - MARGIN - y) // row_h)
         day_events = _events_on_day(events, day, tz)
         for i, event in enumerate(day_events):
             if i >= max_rows:
-                draw_text(img, (x0 + 6, y), f"+{len(day_events) - max_rows}", chip_font, MUTED)
+                draw_text(img, (x0 + 6, y), f"+{len(day_events) - max_rows}", chip_font)
                 break
             colors = _event_colors(event, owners_seen, palette_rgb)
-            _draw_color_bar(draw, x0 + 4, y + 1, x0 + 11, y + row_h - 5, colors, radius=2)
+            panel_style.draw_color_chip(draw, x0 + 4, y + 1, x0 + 11, y + row_h - 5, colors, radius=2)
             if event["all_day"]:
                 _draw_mixed_line(img, draw, (x0 + 16, y), event["summary"], chip_font, col_w - 20)
             else:
@@ -672,39 +670,60 @@ def _build_month(events: list[dict], browse_offset: int, target_w: int, target_h
                  week_start: int, palette_rgb: list | None = None) -> Image.Image:
     """Density dots per day, not literal event text -- real text at
     typical month-cell size (~100x70px) is close to unreadable on a
-    6-color dithered e-ink panel. Capped at 4 visible dots, "+N" beyond."""
-    img = Image.new("RGB", (target_w, target_h), BG)
-    draw = ImageDraw.Draw(img)
+    6-color dithered e-ink panel. Capped at 4 visible dots, "+N" beyond.
+    "Not in this month" day numbers used to be a muted gray -- now
+    de-emphasized by weight instead (Regular vs. Bold), same reasoning
+    as everywhere else this module dropped MUTED -- see module-level
+    comment above MARGIN/BG/FG."""
+    img, draw, (cx0, cy0, cw, ch) = panel_style.card_canvas(target_w, target_h)
 
     header_size, day_size = _MONTH_FONTS[_size_tier(target_w, target_h)]
-    header_font = ImageFont.load_default(size=header_size)
-    day_font = ImageFont.load_default(size=day_size)
+    header_font = panel_style.font_bold(header_size)
+    day_font_in_month = panel_style.font_bold(day_size)
+    day_font_out_of_month = panel_style.font_regular(day_size)
 
     today = datetime.now(tz).date()
     target_month = _add_months(date(today.year, today.month, 1), browse_offset)
     weeks = list(calendar_module.Calendar(firstweekday=week_start).monthdatescalendar(target_month.year, target_month.month))
 
-    col_w = (target_w - MARGIN * 2) // 7
+    col_w = (cw - MARGIN * 2) // 7
     header_h = 28
-    grid_top = MARGIN + header_h
-    row_h = (target_h - MARGIN - grid_top) // len(weeks)
+    grid_top = cy0 + MARGIN + header_h
+    row_h = (cy0 + ch - MARGIN - grid_top) // len(weeks)
+    today_accent = panel_style.theme_color("calendar", palette_rgb)
+    today_badge_r = min(panel_style.CHIP_RADIUS, 9)
 
     day_names = WEEKDAY_NAMES[week_start:] + WEEKDAY_NAMES[:week_start]
     for col, name in enumerate(day_names):
-        draw_text(img, (MARGIN + col * col_w + 6, MARGIN), name[:3], header_font, MUTED)
+        draw_text(img, (cx0 + MARGIN + col * col_w + 6, cy0 + MARGIN), name[:3], header_font)
 
     owners_seen: list[str] = []
     dot_r = 6
     for row, week in enumerate(weeks):
         for col, day in enumerate(week):
-            x0 = MARGIN + col * col_w
+            x0 = cx0 + MARGIN + col * col_w
             y0 = grid_top + row * row_h
             draw.rectangle([x0, y0, x0 + col_w, y0 + row_h], outline=RULE)
             in_month = day.month == target_month.month
-            text_color = FG if in_month else MUTED
             if day == today:
-                draw.rectangle([x0 + 2, y0 + 2, x0 + 24, y0 + 20], outline=FG)
-            draw_text(img, (x0 + 6, y0 + 4), str(day.day), day_font, text_color)
+                # A filled accent badge (this widget's own theme color,
+                # see panel_style.THEME) instead of the old bare outline
+                # -- an actual "today" indicator, not just an outline
+                # easy to miss at ~24px. Sized around the actual digit
+                # bbox (not a fixed pixel box) so a bold 2-digit day
+                # number ("30") fits as comfortably as a single digit
+                # ("3") at every size tier.
+                day_str = str(day.day)
+                text_x, text_y = x0 + 6, y0 + 4
+                dbbox = draw.textbbox((text_x, text_y), day_str, font=day_font_in_month)
+                pad = 3
+                badge_rect = [dbbox[0] - pad, dbbox[1] - pad, dbbox[2] + pad, dbbox[3] + pad]
+                badge_r = min(today_badge_r, (badge_rect[3] - badge_rect[1]) // 2)
+                draw.rounded_rectangle(badge_rect, radius=badge_r, fill=today_accent)
+                draw_text(img, (text_x, text_y), day_str, day_font_in_month, BG)
+            else:
+                day_font = day_font_in_month if in_month else day_font_out_of_month
+                draw_text(img, (x0 + 6, y0 + 4), str(day.day), day_font)
 
             day_events = _events_on_day(events, day, tz)
             dot_x = x0 + 8
@@ -718,7 +737,7 @@ def _build_month(events: list[dict], browse_offset: int, target_w: int, target_h
                 draw.ellipse([dot_x, dot_y, dot_x + dot_r * 2, dot_y + dot_r * 2], fill=event_color)
                 dot_x += dot_r * 2 + 5
             if len(day_events) > 4:
-                draw_text(img, (dot_x, dot_y - 2), f"+{len(day_events) - 4}", header_font, MUTED)
+                draw_text(img, (dot_x, dot_y - 2), f"+{len(day_events) - 4}", header_font)
 
     return img
 
@@ -759,8 +778,13 @@ def _build(events: list[dict], view: str, browse_offset: int, target_w: int, tar
                             weather_cities, weather_units)
 
     if fetch_summary:
-        font = ImageFont.load_default(size=14 if _size_tier(target_w, target_h) != "small" else 11)
-        draw_text(img, (MARGIN, target_h - MARGIN - font.size), fetch_summary, font, MUTED)
+        # Drawn as a final overlay onto the already-composited img (not
+        # inside any one _build_* branch above), so it offsets by
+        # panel_style.GUTTER itself to land inside the same visible
+        # margin every builder's own content already respects.
+        font = panel_style.font_regular(14 if _size_tier(target_w, target_h) != "small" else 11)
+        draw_text(img, (panel_style.GUTTER + MARGIN, target_h - panel_style.GUTTER - MARGIN - font.size),
+                 fetch_summary, font)
 
     return img
 
@@ -815,12 +839,11 @@ def _build_tasks(tasks: list[dict], target_w: int, target_h: int, palette_rgb: l
     """A tasks widget's entire region is the checklist -- unlike the old
     week-view slot, there's no day columns/header to share space with,
     so this is just _draw_tasks over the whole box."""
-    img = Image.new("RGB", (target_w, target_h), BG)
-    draw = ImageDraw.Draw(img)
+    img, draw, region = panel_style.card_canvas(target_w, target_h)
     title_size, body_size = _TASKS_FONTS[_size_tier(target_w, target_h)]
-    title_font = ImageFont.load_default(size=title_size)
-    body_font = ImageFont.load_default(size=body_size)
-    _draw_tasks(img, draw, (0, 0, target_w, target_h), tasks, title_font, body_font, palette_rgb, title)
+    title_font = panel_style.font_bold(title_size)
+    body_font = panel_style.font_regular(body_size)
+    _draw_tasks(img, draw, region, tasks, title_font, body_font, palette_rgb, title)
     return img
 
 

server/app/html_render.py

@@ -0,0 +1,327 @@
+"""Experimental "modern" weather widget render style: Jinja2 + a
+persistent headless Chromium browser (Playwright) instead of the hand-
+drawn PIL primitives in weather_render.py -- see docs/widgets.md and the
+`html-widget-render` branch's PR description for the design rationale
+(gradients/shadows/soft shading that PIL can't easily do, at the cost of
+a real browser-process dependency).
+
+Two things this module owns that nothing else in the codebase needed
+before:
+
+1. A **persistent** background browser process. Widget rendering already
+   happens concurrently across a fresh `ThreadPoolExecutor` per frame
+   request (routers/device.py's _render_widgets) -- Playwright's sync
+   API is thread-affine (an object must be used from the thread that
+   created it), so a single browser object can't be handed across those
+   ad-hoc worker threads, and relaunching a full Chromium process on
+   every widget render would be real, avoidable latency. Fix: one
+   background thread runs its own persistent asyncio event loop hosting
+   one long-lived `Browser`, lazily started on first use (see start()) --
+   not eagerly at server startup, so a deployment that never enables the
+   weather widget's "modern" style never launches Chromium at all and
+   never needs Playwright's browser binaries installed. main.py's
+   lifespan only wires up the *shutdown* half (stop()), so a clean
+   server restart doesn't leave an orphaned Chromium process behind if
+   this was ever actually used. render_html_to_image() is a plain sync
+   function any worker thread can call, bridging in via
+   `asyncio.run_coroutine_threadsafe` (the standard safe cross-thread
+   entry point into a *running* loop on another thread).
+
+2. **Per-region ordered (Bayer) dithering against the palette**, done
+   here rather than in the shared image_pipeline.py pipeline.
+   render_panel's whole-canvas single Floyd-Steinberg pass exists
+   because Floyd-Steinberg's error diffusion can't be split across
+   independently-quantized regions without a visible seam at the
+   boundary -- but that reasoning doesn't apply to ordered dithering,
+   which has no cross-pixel error term (each pixel's dither decision
+   only depends on its own position + color). So this module dithers its
+   own rendered widget to *already-exact* palette colors before
+   returning it; the later shared Floyd-Steinberg pass sees zero
+   quantization error there and leaves it untouched -- the same
+   "pre-commit to exact palette colors" trick image_pipeline.draw_text
+   and the hand-drawn weather icons already rely on, just reached a
+   different way. Floyd-Steinberg keeps working exactly as before for
+   photos and every other (classic-rendered) widget region.
+"""
+
+from __future__ import annotations
+
+import asyncio
+import io
+import threading
+from datetime import date
+from pathlib import Path
+
+import numpy as np
+from jinja2 import Environment, FileSystemLoader, select_autoescape
+from PIL import Image
+
+from . import panel_style
+from .image_pipeline import DEFAULT_PALETTE_RGB
+
+_TEMPLATE_DIR = Path(__file__).resolve().parent / "templates" / "widget_html"
+_FONT_DIR = Path(__file__).resolve().parent / "fonts"
+
+_jinja_env = Environment(
+    loader=FileSystemLoader(str(_TEMPLATE_DIR)),
+    autoescape=select_autoescape(["html", "jinja"]),
+)
+
+CATEGORY_EMOJI = {
+    "clear": "☀️",
+    "partly_cloudy": "⛅",
+    "cloudy": "☁️",
+    "fog": "\U0001f32b️",
+    "rain": "\U0001f327️",
+    "snow": "❄️",
+    "thunderstorm": "⛈️",
+}
+
+# ACCENT_START/END: a fixed blue gradient pair for the "modern" style's
+# card header -- deliberately not routed through panel_style.theme_color
+# (unlike every classic-rendered widget's chrome), since the whole point
+# of this style is the gradient look ordered_dither below then commits
+# to exact palette colors anyway; which literal hex this starts from
+# doesn't matter to the end result the way it would for a flat PIL fill.
+ACCENT_START = "#1c4fd6"
+ACCENT_END = "#6fa8ff"
+
+
+# --- Persistent background browser -------------------------------------
+
+_loop: asyncio.AbstractEventLoop | None = None
+_loop_thread: threading.Thread | None = None
+_browser = None
+_playwright_cm = None
+_start_lock = threading.Lock()
+
+
+async def _launch_browser() -> None:
+    global _browser, _playwright_cm
+    from playwright.async_api import async_playwright
+
+    _playwright_cm = async_playwright()
+    playwright = await _playwright_cm.__aenter__()
+    _browser = await playwright.chromium.launch()
+
+
+async def _close_browser() -> None:
+    global _browser, _playwright_cm
+    if _browser is not None:
+        await _browser.close()
+        _browser = None
+    if _playwright_cm is not None:
+        await _playwright_cm.__aexit__(None, None, None)
+        _playwright_cm = None
+
+
+def start() -> None:
+    """Launches the background event loop + persistent Chromium browser,
+    if not already running. Called lazily by render_html_to_image on
+    first use (not from main.py's lifespan -- see module docstring for
+    why this must stay opt-in) -- exposed directly too, for tests that
+    want to control startup explicitly. Idempotent -- a second call
+    while already started is a no-op."""
+    global _loop, _loop_thread
+    if _loop is not None:
+        return
+    ready = threading.Event()
+
+    def _run() -> None:
+        global _loop
+        loop = asyncio.new_event_loop()
+        asyncio.set_event_loop(loop)
+        _loop = loop
+        ready.set()
+        loop.run_forever()
+
+    _loop_thread = threading.Thread(target=_run, daemon=True, name="html-render-loop")
+    _loop_thread.start()
+    ready.wait()
+    asyncio.run_coroutine_threadsafe(_launch_browser(), _loop).result()
+
+
+def stop() -> None:
+    """Closes the browser and stops the background loop -- called from
+    main.py's lifespan shutdown so a server restart never leaves an
+    orphaned Chromium process behind. No-op if start() was never called
+    (the common case: most deployments never enable "modern" style)."""
+    global _loop, _loop_thread
+    if _loop is None:
+        return
+    asyncio.run_coroutine_threadsafe(_close_browser(), _loop).result()
+    _loop.call_soon_threadsafe(_loop.stop)
+    _loop_thread.join(timeout=5)
+    _loop = None
+    _loop_thread = None
+
+
+async def _screenshot(html: str, target_w: int, target_h: int) -> bytes:
+    page = await _browser.new_page(viewport={"width": target_w, "height": target_h}, device_scale_factor=1)
+    try:
+        await page.set_content(html, wait_until="networkidle")
+        return await page.screenshot()
+    finally:
+        await page.close()
+
+
+def render_html_to_image(html: str, target_w: int, target_h: int) -> Image.Image:
+    """Renders `html` (already sized to target_w x target_h via its own
+    <style>) through the persistent headless Chromium browser and
+    returns an RGB image of exactly that size. Safe to call from any
+    thread -- bridges into the dedicated background asyncio loop via
+    run_coroutine_threadsafe. Lazily calls start() on first use (see its
+    docstring) -- the first "modern" style render on a freshly-started
+    server pays Chromium's launch latency; every render after that reuses
+    the same persistent browser."""
+    if _loop is None:
+        with _start_lock:
+            if _loop is None:
+                start()
+    future = asyncio.run_coroutine_threadsafe(_screenshot(html, target_w, target_h), _loop)
+    png_bytes = future.result()
+    return Image.open(io.BytesIO(png_bytes)).convert("RGB")
+
+
+# --- Ordered (Bayer 8x8) dithering against an arbitrary palette ---------
+
+_BAYER8 = (
+    np.array(
+        [
+            [0, 32, 8, 40, 2, 34, 10, 42],
+            [48, 16, 56, 24, 50, 18, 58, 26],
+            [12, 44, 4, 36, 14, 46, 6, 38],
+            [60, 28, 52, 20, 62, 30, 54, 22],
+            [3, 35, 11, 43, 1, 33, 9, 41],
+            [51, 19, 59, 27, 49, 17, 57, 25],
+            [15, 47, 7, 39, 13, 45, 5, 37],
+            [63, 31, 55, 23, 61, 29, 53, 21],
+        ],
+        dtype=np.float32,
+    )
+    / 64.0
+    - 0.5
+)
+
+
+def ordered_dither(img: Image.Image, palette_rgb: list | None, amplitude: float = 48.0) -> Image.Image:
+    """Bayer-ordered dither of `img` against `palette_rgb` (falls back to
+    DEFAULT_PALETTE_RGB) -- every output pixel is one of the palette's
+    exact colors, spatially patterned rather than error-diffused, so it's
+    safe to run per-region before compositing (see module docstring for
+    why that's not true of Floyd-Steinberg). `amplitude` is the Bayer
+    bias's full swing in 0-255 RGB units before nearest-palette-color
+    matching -- 48 was the value this render style was tuned against in
+    the exploratory spike behind this feature; not exposed as a per-frame
+    setting (unlike dither_strength) since there's only one consumer of
+    it today."""
+    palette = np.array(palette_rgb or DEFAULT_PALETTE_RGB, dtype=np.float32)
+    arr = np.asarray(img.convert("RGB"), dtype=np.float32)
+    h, w, _ = arr.shape
+    tile = np.tile(_BAYER8, (h // 8 + 1, w // 8 + 1))[:h, :w]
+    biased = np.clip(arr + tile[:, :, None] * amplitude, 0, 255)
+    diffs = biased[:, :, None, :] - palette[None, None, :, :]
+    dists = np.einsum("hwkc,hwkc->hwk", diffs, diffs)
+    idx = np.argmin(dists, axis=2)
+    return Image.fromarray(palette[idx].astype(np.uint8), "RGB")
+
+
+# --- Weather "modern" style ----------------------------------------------
+
+def _day_label(day_date: date) -> str:
+    delta = (day_date - date.today()).days
+    if delta == 0:
+        return "Today"
+    if delta == 1:
+        return "Tomorrow"
+    return day_date.strftime("%a")
+
+
+def build_current(entry: dict | None, target_w: int, target_h: int, palette_rgb: list | None = None,
+                  units: str = "fahrenheit", city_label: str = "") -> Image.Image:
+    """HTML/CSS-rendered analogue of weather_render.build_current --
+    same call signature, so app/widgets/weather.py can dispatch to
+    either interchangeably. Returns an already-palette-exact RGB image
+    (see ordered_dither)."""
+    img = Image.new("RGB", (target_w, target_h), (255, 255, 255))
+    if not entry:
+        return img
+
+    unit_suffix = "F" if units == "fahrenheit" else "C"
+    icon_size = max(28, min(target_w, target_h) // 3)
+    template = _jinja_env.get_template("weather_current.html.jinja")
+    html = template.render(
+        w=target_w, h=target_h, gutter=panel_style.GUTTER, radius=panel_style.CARD_RADIUS,
+        font_dir=str(_FONT_DIR), emoji=CATEGORY_EMOJI.get(entry["category"], ""),
+        temp=round(entry["temp"]), unit_suffix=unit_suffix, city_label=city_label,
+        icon_size=icon_size, temp_size=max(24, min(target_w, target_h) // 3),
+        label_size=max(12, icon_size // 3),
+    )
+    rendered = render_html_to_image(html, target_w, target_h)
+    return ordered_dither(rendered, palette_rgb)
+
+
+def build_daily(daily: dict[str, dict], target_w: int, target_h: int, palette_rgb: list | None = None,
+               units: str = "fahrenheit", city_label: str = "") -> Image.Image:
+    """HTML/CSS-rendered analogue of weather_render.build_daily -- same
+    call signature. Returns an already-palette-exact RGB image (see
+    ordered_dither)."""
+    img = Image.new("RGB", (target_w, target_h), (255, 255, 255))
+    days = list(daily.items())
+    if not days:
+        return img
+
+    unit_suffix = "F" if units == "fahrenheit" else "C"
+    header_h = max(28, min(target_w, target_h) // 8) if city_label else 0
+    col_w = max(1, target_w // len(days))
+    icon_size = max(16, min(col_w // 2, 36))
+    day_entries = [
+        {
+            "label": _day_label(date.fromisoformat(day_str)),
+            "emoji": CATEGORY_EMOJI.get(d["category"], ""),
+            "high": round(d["high"]),
+            "low": round(d["low"]),
+        }
+        for day_str, d in days
+    ]
+    template = _jinja_env.get_template("weather_daily.html.jinja")
+    html = template.render(
+        w=target_w, h=target_h, gutter=panel_style.GUTTER, radius=panel_style.CARD_RADIUS,
+        font_dir=str(_FONT_DIR), city_label=city_label, header_h=header_h,
+        title_size=max(14, header_h - 12), accent_start=ACCENT_START, accent_end=ACCENT_END,
+        days=day_entries, icon_size=icon_size, label_size=max(12, icon_size // 2),
+        unit_suffix=unit_suffix,
+    )
+    rendered = render_html_to_image(html, target_w, target_h)
+    return ordered_dither(rendered, palette_rgb)
+
+
+SUPPORTED_MODES = ("current", "daily")
+
+
+def build(mode: str, data, target_w: int, target_h: int, palette_rgb: list | None = None,
+         units: str = "fahrenheit", city_label: str = "") -> Image.Image:
+    """Dispatches to build_current/build_daily -- mirrors weather_render.
+    build()'s signature (minus interval_hours, which no modern-style mode
+    uses) so app/widgets/weather.py and the weather preview endpoint can
+    call either module identically. Only call this for mode in
+    SUPPORTED_MODES -- callers are expected to have already fallen back to
+    weather_render.build() for hourly/multi_city (see weather.py)."""
+    if mode == "current":
+        return build_current(data, target_w, target_h, palette_rgb, units, city_label)
+    return build_daily(data, target_w, target_h, palette_rgb, units, city_label)
+
+
+def render_weather_preview_png(mode: str, data, orientation: str, palette_rgb: list | None,
+                               units: str = "fahrenheit", city_label: str = "") -> bytes:
+    """Modern-style analogue of weather_render.render_weather_preview_png
+    -- same browser-viewable-PNG convention every other widget's preview
+    endpoint uses. build()'s output is already palette-exact (see
+    ordered_dither), so the final _quantize pass here is a no-op on it,
+    same reasoning as the module docstring's compositing story."""
+    from .image_pipeline import _quantize, _png_bytes, logical_render_size
+
+    target_w, target_h = logical_render_size(orientation)
+    img = build(mode, data, target_w, target_h, palette_rgb, units, city_label)
+    quantized = _quantize(img, palette_rgb, dither_strength=1.0)
+    return _png_bytes(quantized)

server/app/image_pipeline.py

@@ -61,7 +61,8 @@ def _dotted_edge(draw: ImageDraw.ImageDraw, x0: float, y0: float, x1: float, y1:
         pos += spacing
 
 
-def draw_widget_border(img: Image.Image, style: str, thickness: int, color: tuple[int, int, int]) -> None:
+def draw_widget_border(img: Image.Image, style: str, thickness: int, color: tuple[int, int, int],
+                       radius: int = 0) -> None:
     """Draws a border inset within img's own bounds, mutating it in
     place -- called once per widget's own region (routers/device.py's
     _render_widgets, and each widget type's own dialog preview) before
@@ -74,24 +75,44 @@ def draw_widget_border(img: Image.Image, style: str, thickness: int, color: tupl
     "solid"/"dashed"/"dotted" are a single thickness-px stroke traced
     just inside the image's edge; "fancy" is two thinner concentric
     strokes with a gap between them, picture-frame-mat style. "none" (or
-    a non-positive thickness) draws nothing."""
+    a non-positive thickness) draws nothing. `radius` is opt-in and only
+    honored by "solid"/"fancy" (rounded_rectangle instead of rectangle) --
+    "dashed"/"dotted" trace each of the 4 edges as independent straight
+    segments (see _dashed_edge/_dotted_edge) and ignore it, a documented
+    limitation rather than a bug. Defaults to 0 (unchanged sharp-corner
+    behavior) and no call site passes non-zero today -- this ships the
+    capability for a future per-widget "rounded border" setting without
+    changing default behavior anywhere (see tests/test_widget_border.py's
+    exact-corner-pixel assertions)."""
     if style == "none" or thickness <= 0:
         return
     w, h = img.size
     t = max(1, min(int(thickness), min(w, h) // 2))
     draw = ImageDraw.Draw(img)
+    r = max(0, min(radius, (w - 1) // 2, (h - 1) // 2))
 
     if style == "fancy":
         line_t = max(1, t // 3)
         gap = max(2, t - 2 * line_t)
-        draw.rectangle([0, 0, w - 1, h - 1], outline=color, width=line_t)
+        if r:
+            draw.rounded_rectangle([0, 0, w - 1, h - 1], radius=r, outline=color, width=line_t)
+        else:
+            draw.rectangle([0, 0, w - 1, h - 1], outline=color, width=line_t)
         inset = line_t + gap
         if w - 2 * inset > 1 and h - 2 * inset > 1:
-            draw.rectangle([inset, inset, w - 1 - inset, h - 1 - inset], outline=color, width=line_t)
+            inner_r = max(0, min(r - inset, (w - 1 - 2 * inset) // 2, (h - 1 - 2 * inset) // 2)) if r else 0
+            if inner_r:
+                draw.rounded_rectangle([inset, inset, w - 1 - inset, h - 1 - inset], radius=inner_r,
+                                       outline=color, width=line_t)
+            else:
+                draw.rectangle([inset, inset, w - 1 - inset, h - 1 - inset], outline=color, width=line_t)
         return
 
     if style == "solid":
-        draw.rectangle([0, 0, w - 1, h - 1], outline=color, width=t)
+        if r:
+            draw.rounded_rectangle([0, 0, w - 1, h - 1], radius=r, outline=color, width=t)
+        else:
+            draw.rectangle([0, 0, w - 1, h - 1], outline=color, width=t)
         return
 
     # dashed/dotted trace the same centered-on-the-edge path solid/
@@ -166,6 +187,27 @@ DEFAULT_PALETTE_RGB = [
 
 PALETTE_LABELS = ["Black", "White", "Yellow", "Red", "Blue", "Green"]
 
+# A community-measured alternative starting point for the same 6 slots,
+# ported (data only, not code) from paperlesspaper/epdoptimize's
+# src/dither/data/default-palettes.json "spectra6" entry (Apache
+# License 2.0, https://github.com/paperlesspaper/epdoptimize) -- offered
+# as a one-click "Load calibrated preset" in the Advanced configuration
+# UI, not a new default: unlike DEFAULT_PALETTE_RGB above, these are an
+# actual panel's measured appearance rather than idealized primaries
+# (real Spectra 6 white/black are notably duller than pure #fff/#000),
+# but measured from a different unit than any given frame's actual
+# panel -- panel_style.py's own docstring already notes units vary
+# enough to be worth calibrating per frame, and this hasn't been
+# verified against this project's own hardware.
+CALIBRATED_SPECTRA6_RGB = [
+    (0x1F, 0x22, 0x26),  # BLACK
+    (0xB9, 0xC7, 0xC9),  # WHITE
+    (0xC1, 0xBB, 0x1E),  # YELLOW
+    (0x62, 0x20, 0x1E),  # RED
+    (0x23, 0x3F, 0x8E),  # BLUE
+    (0x35, 0x56, 0x3A),  # GREEN
+]
+
 # The panel's actual 4-bit color codes (see firmware/components/epd7in3e),
 # in the same order as DEFAULT_PALETTE_RGB/PALETTE_LABELS -- fixed by the
 # hardware protocol, never user-configurable. 0x4 is intentionally unused

server/app/main.py

@@ -17,6 +17,7 @@ from __future__ import annotations
 
 import logging
 import time
+from contextlib import asynccontextmanager
 
 from fastapi import FastAPI, Request
 from fastapi.responses import FileResponse, HTMLResponse, RedirectResponse
@@ -24,7 +25,7 @@ from fastapi.staticfiles import StaticFiles
 from fastapi.templating import Jinja2Templates
 from sqlalchemy import select
 
-from . import logging_setup, migration
+from . import html_render, logging_setup, migration
 from .auth import (
     browser_token_valid,
     current_user,
@@ -46,7 +47,20 @@ logging_setup.configure_logging()
 # Schema + legacy-config import, before the first request is served.
 migration.run_migrations()
 
-app = FastAPI(title="ESPresso Frame Server")
+@asynccontextmanager
+async def _lifespan(app: FastAPI):
+    """Startup does nothing browser-related -- html_render.start() is
+    lazy (only the weather widget's opt-in "modern" render style ever
+    triggers it, see that module's docstring), so a deployment that
+    never uses it never launches Chromium or needs Playwright's browser
+    binaries installed. Shutdown calls html_render.stop() unconditionally
+    (a no-op if it was never started) so a server restart never leaves
+    an orphaned Chromium process running."""
+    yield
+    html_render.stop()
+
+
+app = FastAPI(title="ESPresso Frame Server", lifespan=_lifespan)
 templates = Jinja2Templates(directory="app/templates")
 
 

server/app/manage_overlay.py

@@ -14,7 +14,8 @@ from __future__ import annotations
 
 from PIL import Image, ImageDraw, ImageFont
 
-from .image_pipeline import DEFAULT_PALETTE_RGB, draw_text
+from . import panel_style
+from .image_pipeline import draw_text
 
 PADDING = 16
 QR_TEXT_GAP = 8
@@ -27,9 +28,12 @@ BODY_FONT_SIZE = 20
 
 BATTERY_ICON_W = 40
 BATTERY_ICON_H = 22
-BATTERY_ICON_STROKE = 2
+# Stroke/nub width/height are no longer fixed constants here -- panel_
+# style.draw_battery_icon derives them from icon_w/icon_h itself (same
+# formula widgets/battery.py's own icon already used). BATTERY_NUB_W
+# below is kept only as this box's own outer-width estimate, not fed
+# into the icon drawing itself.
 BATTERY_NUB_W = 5
-BATTERY_NUB_H = 10
 BATTERY_ICON_TEXT_GAP = 8
 BATTERY_REGION_GAP = 8  # vertical gap below the manage QR box
 
@@ -37,10 +41,6 @@ FACE_LABEL_PADDING = 8
 FACE_LABEL_GAP = 4  # distance from the face's anchor point to the label box
 
 
-def _font(size: int) -> ImageFont.ImageFont:
-    return ImageFont.load_default(size=size)
-
-
 def _qr_image(url: str, target_px: int = QR_TARGET_PX) -> Image.Image:
     import qrcode
 
@@ -52,7 +52,7 @@ def _qr_image(url: str, target_px: int = QR_TARGET_PX) -> Image.Image:
     return raw.resize((raw.width * scale, raw.height * scale), Image.NEAREST)
 
 
-def _text_box(draw: ImageDraw.ImageDraw, lines: list[str], font: ImageFont.ImageFont) -> tuple[int, int]:
+def _text_box(draw: ImageDraw.ImageDraw, lines: list[str], font: ImageFont.FreeTypeFont) -> tuple[int, int]:
     """(width, height) of `lines` stacked with LINE_GAP between them, at
     `font` -- the box _draw_text_box below will need."""
     w = 0
@@ -64,7 +64,7 @@ def _text_box(draw: ImageDraw.ImageDraw, lines: list[str], font: ImageFont.Image
     return w, h
 
 
-def _draw_centered_lines(img: Image.Image, draw: ImageDraw.ImageDraw, lines: list[str], font: ImageFont.ImageFont,
+def _draw_centered_lines(img: Image.Image, draw: ImageDraw.ImageDraw, lines: list[str], font: ImageFont.FreeTypeFont,
                          center_x: int, top: int) -> None:
     y = top
     for line in lines:
@@ -82,7 +82,8 @@ def _draw_qr_box(img: Image.Image, draw: ImageDraw.ImageDraw, url: str, caption:
     (the battery, below the manage QR) use it instead of recomputing the
     same geometry a second time."""
     qr_img = _qr_image(url)
-    text_w, text_h = _text_box(draw, caption, _font(TITLE_FONT_SIZE)) if caption else (0, 0)
+    caption_font = panel_style.font_bold(TITLE_FONT_SIZE)
+    text_w, text_h = _text_box(draw, caption, caption_font) if caption else (0, 0)
     content_w = max(qr_img.width, text_w)
     content_h = qr_img.height + (QR_TEXT_GAP + text_h if caption else 0)
 
@@ -90,24 +91,26 @@ def _draw_qr_box(img: Image.Image, draw: ImageDraw.ImageDraw, url: str, caption:
     h = content_h + PADDING * 2
     x0, y0 = _corner_origin(img.size, (w, h), corner)
 
-    draw.rectangle([x0, y0, x0 + w, y0 + h], fill=(255, 255, 255), outline=(0, 0, 0))
+    draw.rounded_rectangle([x0, y0, x0 + w, y0 + h], radius=panel_style.CHIP_RADIUS,
+                           fill=(255, 255, 255), outline=(0, 0, 0))
     center_x = x0 + w // 2
     img.paste(qr_img, (center_x - qr_img.width // 2, y0 + PADDING))
     if caption:
-        _draw_centered_lines(img, draw, caption, _font(TITLE_FONT_SIZE), center_x, y0 + PADDING + qr_img.height + QR_TEXT_GAP)
+        _draw_centered_lines(img, draw, caption, caption_font, center_x, y0 + PADDING + qr_img.height + QR_TEXT_GAP)
     return x0, y0, w, h
 
 
 def _draw_text_box(img: Image.Image, draw: ImageDraw.ImageDraw, lines: list[str], corner: str) -> None:
     """White-padded box with centered text lines, placed in one of the
     panel's four corners."""
-    font = _font(BODY_FONT_SIZE)
+    font = panel_style.font_regular(BODY_FONT_SIZE)
     text_w, text_h = _text_box(draw, lines, font)
     w = text_w + PADDING * 2
     h = text_h + PADDING * 2
     x0, y0 = _corner_origin(img.size, (w, h), corner)
 
-    draw.rectangle([x0, y0, x0 + w, y0 + h], fill=(255, 255, 255), outline=(0, 0, 0))
+    draw.rounded_rectangle([x0, y0, x0 + w, y0 + h], radius=panel_style.CHIP_RADIUS,
+                           fill=(255, 255, 255), outline=(0, 0, 0))
     _draw_centered_lines(img, draw, lines, font, x0 + w // 2, y0 + PADDING)
 
 
@@ -123,34 +126,17 @@ def _corner_origin(img_size: tuple[int, int], box_size: tuple[int, int], corner:
     return img_w - PANEL_MARGIN - box_w, img_h - PANEL_MARGIN - box_h  # bottom-right
 
 
-# DEFAULT_PALETTE_RGB order is [BLACK, WHITE, YELLOW, RED, BLUE, GREEN]
-# (see image_pipeline.PANEL_CODES) -- picked by level so the fill itself
-# carries the "how worried should I be" signal, not just the number next
-# to it. Thresholds match the low-battery-alert spirit elsewhere in this
-# project (not tied to a frame's own configured alert threshold, since
-# this glyph has to make sense with no configuration at all).
-_BATTERY_LOW = DEFAULT_PALETTE_RGB[3]  # red
-_BATTERY_MEDIUM = DEFAULT_PALETTE_RGB[2]  # yellow
-_BATTERY_HIGH = DEFAULT_PALETTE_RGB[5]  # green
-
-
-def _battery_fill_color(percent: int) -> tuple[int, int, int]:
-    if percent <= 15:
-        return _BATTERY_LOW
-    if percent <= 40:
-        return _BATTERY_MEDIUM
-    return _BATTERY_HIGH
-
-
 def _draw_battery(img: Image.Image, draw: ImageDraw.ImageDraw, percent: int, anchor_x0: int, anchor_y0: int,
                   anchor_w: int, anchor_h: int) -> None:
-    """Battery glyph (now actually filled to `percent`, not just a static
-    outline -- easy now that this renders server-side instead of being a
-    fixed bitmap firmware drew) + "NN%" text, right-aligned under the
-    given anchor box (the manage QR box) -- a sensible default position,
-    not a constraint anything else has to route around; move this call
-    site's arguments to place it anywhere else instead."""
-    font = _font(BODY_FONT_SIZE)
+    """Battery glyph + "NN%" text, right-aligned under the given anchor
+    box (the manage QR box) -- a sensible default position, not a
+    constraint anything else has to route around; move this call site's
+    arguments to place it anywhere else instead. The glyph itself is
+    panel_style.draw_battery_icon -- the one shared implementation
+    replacing what used to be a second, independent copy of widgets/
+    battery.py's own icon-drawing code (same shape, same red/yellow/
+    green thresholds, previously kept in sync by convention only)."""
+    font = panel_style.font_regular(BODY_FONT_SIZE)
     text = f"{percent}%"
     icon_total_w = BATTERY_ICON_W + BATTERY_NUB_W
     text_w = draw.textlength(text, font=font)
@@ -162,22 +148,14 @@ def _draw_battery(img: Image.Image, draw: ImageDraw.ImageDraw, percent: int, anc
     x0 = anchor_x0 + anchor_w - w
     y0 = anchor_y0 + anchor_h + BATTERY_REGION_GAP
 
-    draw.rectangle([x0, y0, x0 + w, y0 + h], fill=(255, 255, 255), outline=(0, 0, 0))
+    draw.rounded_rectangle([x0, y0, x0 + w, y0 + h], radius=panel_style.CHIP_RADIUS,
+                           fill=(255, 255, 255), outline=(0, 0, 0))
 
     icon_x = x0 + PADDING
     icon_y = y0 + PADDING + (content_h - BATTERY_ICON_H) // 2
-    inner_x0, inner_y0 = icon_x + BATTERY_ICON_STROKE, icon_y + BATTERY_ICON_STROKE
-    inner_x1, inner_y1 = icon_x + BATTERY_ICON_W - BATTERY_ICON_STROKE, icon_y + BATTERY_ICON_H - BATTERY_ICON_STROKE
-    fill_x1 = inner_x0 + round((inner_x1 - inner_x0) * (percent / 100))
-    if fill_x1 > inner_x0:
-        draw.rectangle([inner_x0, inner_y0, fill_x1, inner_y1], fill=_battery_fill_color(percent))
-    draw.rectangle([icon_x, icon_y, icon_x + BATTERY_ICON_W, icon_y + BATTERY_ICON_H], outline=(0, 0, 0),
-                   width=BATTERY_ICON_STROKE)
-    nub_y = icon_y + (BATTERY_ICON_H - BATTERY_NUB_H) // 2
-    draw.rectangle([icon_x + BATTERY_ICON_W, nub_y, icon_x + BATTERY_ICON_W + BATTERY_NUB_W, nub_y + BATTERY_NUB_H],
-                   fill=(0, 0, 0))
+    panel_style.draw_battery_icon(draw, icon_x, icon_y, BATTERY_ICON_W, BATTERY_ICON_H, percent)
     draw_text(img, (icon_x + icon_total_w + BATTERY_ICON_TEXT_GAP, y0 + PADDING + (content_h - font.size) // 2),
-             text, font)
+             text, font, panel_style.battery_fill_color(percent))
 
 
 def _draw_face_label(img: Image.Image, draw: ImageDraw.ImageDraw, name: str, anchor_x: int, anchor_y: int) -> None:
@@ -185,7 +163,7 @@ def _draw_face_label(img: Image.Image, draw: ImageDraw.ImageDraw, name: str, anc
     anchor_y) point, flipped above if there's no room below, clamped to
     stay fully on-panel -- unlike the four corner boxes (always in-bounds
     by construction), a face can be anywhere, including near an edge."""
-    font = _font(BODY_FONT_SIZE)
+    font = panel_style.font_regular(BODY_FONT_SIZE)
     text_w = draw.textlength(name, font=font)
     bbox = draw.textbbox((0, 0), name, font=font)
     text_h = bbox[3] - bbox[1]
@@ -201,7 +179,8 @@ def _draw_face_label(img: Image.Image, draw: ImageDraw.ImageDraw, name: str, anc
     x0 = max(0, min(x0, img_w - w))
     y0 = max(0, min(y0, img_h - h))
 
-    draw.rectangle([x0, y0, x0 + w, y0 + h], fill=(255, 255, 255), outline=(0, 0, 0))
+    draw.rounded_rectangle([x0, y0, x0 + w, y0 + h], radius=panel_style.CHIP_RADIUS,
+                           fill=(255, 255, 255), outline=(0, 0, 0))
     draw_text(img, (x0 + FACE_LABEL_PADDING, y0 + FACE_LABEL_PADDING - bbox[1]), name, font)
 
 

server/app/migration.py

@@ -798,6 +798,22 @@ def _migration_30(conn) -> None:
         conn.execute(text("ALTER TABLE frames ADD COLUMN last_displayed_at REAL NOT NULL DEFAULT 0.0"))
 
 
+def _migration_31(conn) -> None:
+    """Weather widget render style (models.WeatherWidgetConfig.
+    render_style): "classic" (existing hand-drawn PIL renderer,
+    unchanged) or "modern" (app/html_render.py's headless-Chromium/CSS
+    renderer). Every existing weather widget defaults to "classic" --
+    no behavior change until a widget's dialog switches it.
+
+    Guarded per-column, same reasoning as migration 30's own comment:
+    weather_widget_configs is a table some replay tests may re-create
+    fresh via create_all() (which already has this column) rather than
+    replaying migration 24's raw CREATE TABLE."""
+    existing = {c["name"] for c in inspect(conn).get_columns("weather_widget_configs")}
+    if "render_style" not in existing:
+        conn.execute(text("ALTER TABLE weather_widget_configs ADD COLUMN render_style TEXT NOT NULL DEFAULT 'classic'"))
+
+
 MIGRATIONS = [
     (1, _migration_1),
     (2, _migration_2),
@@ -829,6 +845,7 @@ MIGRATIONS = [
     (28, _migration_28),
     (29, _migration_29),
     (30, _migration_30),
+    (31, _migration_31),
 ]
 
 

server/app/models.py

@@ -607,13 +607,19 @@ class WeatherWidgetConfig(Base):
     `cached`'s shape depends on `mode`: {"temp","category"} for current,
     a list of {"time","temp","category"} for hourly, a
     {"YYYY-MM-DD": {...}} dict for daily, or a list of
-    {"label","high","low","category"} for multi_city."""
+    {"label","high","low","category"} for multi_city.
+    `render_style` picks which renderer draws the widget: "classic" (the
+    hand-drawn PIL primitives in app/weather_render.py, unchanged
+    default) or "modern" (app/html_render.py's Jinja2/headless-Chromium
+    path, "current"/"daily" modes only for now -- see weather.py's
+    render())."""
 
     __tablename__ = "weather_widget_configs"
 
     widget_id: Mapped[int] = mapped_column(ForeignKey("widgets.id", ondelete="CASCADE"), primary_key=True)
     mode: Mapped[str] = mapped_column(String, default="current")  # current | hourly | daily | multi_city
     provider: Mapped[str] = mapped_column(String, default="open_meteo")  # open_meteo | nws
+    render_style: Mapped[str] = mapped_column(String, default="classic")  # classic | modern
     units: Mapped[str] = mapped_column(String, default="fahrenheit")  # fahrenheit | celsius
     # Single-location modes only (current/hourly/daily) -- geocoded once
     # via weather.geocode_city() when set, same idiom as

server/app/panel_style.py

@@ -0,0 +1,184 @@
+"""Shared visual language for everything drawn onto the e-ink panel
+(excluding widgets/text.py, which already has its own richer multi-
+family font picker and is left alone) -- spacing, ink-color resolution,
+Inter font loading, and the small set of drawing primitives
+(header bar, color chip, battery icon) more than one render module needs.
+
+Centralizes what used to be independently redefined per render file
+(calendar_render.py/weather_render.py each had their own MARGIN/BG/FG/
+RULE, widgets/battery.py and manage_overlay.py each had their own
+battery-glyph-drawing code) so the panel reads as one consistent system
+instead of N separately-styled widgets. Still bound by the same hard
+constraints as everything else that draws before the single whole-canvas
+quantize/dither pass (see image_pipeline.py's module docstring/draw_text):
+every fill here is one of DEFAULT_PALETTE_RGB's 6 exact colors, and text
+always routes through image_pipeline.draw_text.
+"""
+
+from __future__ import annotations
+
+from functools import lru_cache
+from pathlib import Path
+
+from PIL import Image, ImageDraw, ImageFont
+
+from .image_pipeline import DEFAULT_PALETTE_RGB
+
+# Spacing scale. CONTENT_MARGIN carries over calendar_render.py/
+# weather_render.py's own long-tuned MARGIN=20 value unchanged (not
+# re-tuned -- every wrap/truncation-width calc in those modules was
+# measured against it). GUTTER is new: the inset every widget applies
+# within its own target_w x target_h box (see card_canvas) to get a
+# visible seam between adjacent widgets without touching grid.py's
+# zero-gap cell math.
+GUTTER = 6
+CONTENT_MARGIN = 20
+CARD_RADIUS = 12
+CHIP_RADIUS = 4
+
+# Index constants into DEFAULT_PALETTE_RGB/a frame's own Frame.
+# palette_rgb override -- same order as image_pipeline.PALETTE_LABELS.
+BLACK, WHITE, YELLOW, RED, BLUE, GREEN = range(6)
+
+# Which accent ink each widget kind's chrome (header bar, task checkbox,
+# etc.) uses -- one dict, so "what color is a calendar header" has a
+# single answer instead of being hardcoded separately everywhere a
+# render module wants it. This is what makes a future global color
+# theme *possible* without another pass through every render module: a
+# per-frame override just needs to pick a different THEME mapping (or
+# remap individual entries) here and resolve through theme_color/ink
+# below, which already goes through a frame's own tuned Frame.
+# palette_rgb -- swapping a slot's actual RGB (e.g. a custom "blue")
+# already re-themes every widget that uses THEME_CALENDAR for its
+# header, with no other code to touch. Weather deliberately maps to
+# BLACK, not a color -- see weather_render's header call site -- so its
+# own hand-drawn, already-colorful icons stay the star.
+THEME_CALENDAR = BLUE
+THEME_TASKS = GREEN
+THEME_WEATHER = BLACK
+THEME = {"calendar": THEME_CALENDAR, "tasks": THEME_TASKS, "weather": THEME_WEATHER}
+
+
+def theme_color(widget_kind: str, palette_rgb: list | None = None) -> tuple[int, int, int]:
+    """THEME[widget_kind] resolved against this frame's actual palette --
+    the one call every render module's header/accent chrome should go
+    through instead of hardcoding a palette index inline."""
+    return ink(palette_rgb, THEME[widget_kind])
+
+
+def ink(palette_rgb: list | None, index: int) -> tuple[int, int, int]:
+    """One of this frame's actual panel colors by DEFAULT_PALETTE_RGB
+    index -- generalizes the same resolution idiom weather_render._ink/
+    calendar_render._event_colors already used locally, so a custom
+    palette override (Frame.palette_rgb) still gets its own actual
+    yellow/red/blue/green, and every fill stays an exact, ditherless
+    palette match either way."""
+    return tuple((palette_rgb or DEFAULT_PALETTE_RGB)[index])
+
+
+_FONT_DIR = Path(__file__).resolve().parent / "fonts"
+
+
+@lru_cache(maxsize=256)
+def font_bold(size: int) -> ImageFont.FreeTypeFont:
+    return ImageFont.truetype(str(_FONT_DIR / "Inter-Bold.ttf"), size)
+
+
+@lru_cache(maxsize=256)
+def font_regular(size: int) -> ImageFont.FreeTypeFont:
+    return ImageFont.truetype(str(_FONT_DIR / "Inter-Regular.ttf"), size)
+
+
+def card_canvas(target_w: int, target_h: int,
+               bg: tuple[int, int, int] = (255, 255, 255)) -> tuple:
+    """A full target_w x target_h canvas filled with `bg`, plus the
+    GUTTER-inset rect (x0, y0, w, h) every widget should draw its actual
+    chrome/content within -- this is the whole mechanism behind the
+    gutter between widgets (see module docstring): the widget's render()
+    contract (exact target_w x target_h in, same size out, unchanged) is
+    what routers/device.py pastes and what draw_widget_border frames, so
+    a border still frames the widget's true full box; only the widget's
+    own drawing backs off from that box's true edge."""
+    img = Image.new("RGB", (target_w, target_h), bg)
+    draw = ImageDraw.Draw(img)
+    x0, y0 = GUTTER, GUTTER
+    w, h = max(1, target_w - 2 * GUTTER), max(1, target_h - 2 * GUTTER)
+    return img, draw, (x0, y0, w, h)
+
+
+def _clamped_radius(radius: int, w: int, h: int) -> int:
+    return max(0, min(radius, w // 2, h // 2))
+
+
+def draw_header_bar(draw: ImageDraw.ImageDraw, rect: tuple[int, int, int, int], height: int,
+                    fill: tuple[int, int, int], radius: int = CARD_RADIUS) -> None:
+    """A widget's title bar: rounded top corners only (corners=(tl, tr,
+    bl, br), the bottom pair left square) so it reads as a card's header
+    fused to the content below it, not a standalone pill floating with a
+    gap above its own body."""
+    x0, y0, w, h = rect
+    r = _clamped_radius(radius, w, height * 2)
+    draw.rounded_rectangle([x0, y0, x0 + w, y0 + height], radius=r, fill=fill,
+                           corners=(True, True, False, False))
+
+
+def draw_color_chip(draw: ImageDraw.ImageDraw, x0: int, y0: int, x1: int, y1: int,
+                    colors: list[tuple[int, int, int]], radius: int = CHIP_RADIUS) -> None:
+    """One rounded chip for a single-source event/task, or that same
+    footprint split into equal-width side-by-side segments -- one per
+    contributing calendar -- for a deduplicated shared event (see
+    calendar_render._event_colors/calendar_feed.merge_events). Splitting
+    rather than e.g. concentric rings keeps every color equally "thick
+    and bold" at a glance, the same design goal a single pinned color
+    already has. Generalizes calendar_render.py's old private
+    _draw_color_bar so the radius comes from one shared constant."""
+    if len(colors) == 1:
+        r = _clamped_radius(radius, x1 - x0, y1 - y0)
+        draw.rounded_rectangle([x0, y0, x1, y1], radius=r, fill=colors[0])
+        return
+    seg_w = (x1 - x0) / len(colors)
+    for i, color in enumerate(colors):
+        seg_x0 = round(x0 + i * seg_w)
+        seg_x1 = round(x0 + (i + 1) * seg_w) - (2 if i < len(colors) - 1 else 0)
+        draw.rectangle([seg_x0, y0, seg_x1, y1], fill=color)
+
+
+def battery_fill_color(percent: int, palette_rgb: list | None = None) -> tuple[int, int, int]:
+    """Red/yellow/green by charge level -- the fill itself carries the
+    "how worried should I be" signal, not just the number next to it.
+    Shared threshold logic for widgets/battery.py and manage_overlay.py,
+    which previously each defined the same three-tier thresholds twice."""
+    if percent <= 15:
+        return ink(palette_rgb, RED)
+    if percent <= 40:
+        return ink(palette_rgb, YELLOW)
+    return ink(palette_rgb, GREEN)
+
+
+def draw_battery_icon(draw: ImageDraw.ImageDraw, x0: int, y0: int, icon_w: int, icon_h: int,
+                      percent: int, palette_rgb: list | None = None) -> None:
+    """A rounded battery glyph -- outline + charge-level fill + terminal
+    nub -- anchored at (x0, y0), the body's own top-left corner (the nub
+    extends past icon_w on the right). The one shared implementation
+    behind what used to be two separate ImageDraw glyphs: widgets/
+    battery.py's own icon+percent widget, and manage_overlay.py's compact
+    battery readout on the "scan to manage" overlay -- same shape, same
+    red/yellow/green thresholds, previously kept in sync by convention
+    rather than by sharing code."""
+    stroke = max(2, icon_h // 12)
+    nub_w = max(3, icon_w // 10)
+    nub_h = icon_h // 2
+    radius = _clamped_radius(icon_h // 6, icon_w, icon_h)
+
+    inner_x0, inner_y0 = x0 + stroke, y0 + stroke
+    inner_x1, inner_y1 = x0 + icon_w - stroke, y0 + icon_h - stroke
+    fill_x1 = inner_x0 + round((inner_x1 - inner_x0) * (max(0, min(100, percent)) / 100))
+    if fill_x1 > inner_x0:
+        fill_radius = _clamped_radius(radius, fill_x1 - inner_x0, inner_y1 - inner_y0)
+        draw.rounded_rectangle([inner_x0, inner_y0, fill_x1, inner_y1], radius=fill_radius,
+                               fill=battery_fill_color(percent, palette_rgb))
+    draw.rounded_rectangle([x0, y0, x0 + icon_w, y0 + icon_h], radius=radius, outline=(0, 0, 0), width=stroke)
+    nub_y = y0 + (icon_h - nub_h) // 2
+    nub_radius = _clamped_radius(max(1, nub_w // 3), nub_w, nub_h)
+    draw.rounded_rectangle([x0 + icon_w, nub_y, x0 + icon_w + nub_w, nub_y + nub_h], radius=nub_radius,
+                           fill=(0, 0, 0))

server/app/routers/api_layouts.py

@@ -63,6 +63,10 @@ LAYOUT_CONFIG_FIELDS: dict[str, tuple[str, ...]] = {
     "text": ("content", "font_size", "font_family", "align", "background_color"),
     "whiteboard": ("user_id", "url"),
     "battery": ("mode",),
+    "weather": (
+        "mode", "provider", "units", "city_label", "city_latitude", "city_longitude",
+        "hourly_interval_hours", "daily_days", "cities", "render_style",
+    ),
 }
 
 # widget_type -> (FrameCalendar|FrameTaskList model, SavedLayoutSource.kind)

server/app/routers/api_widgets.py

@@ -341,6 +341,7 @@ def api_widget_config_save(
     weather_units: str | None = Form(None),
     weather_hourly_interval_hours: int | None = Form(None),
     weather_daily_days: int | None = Form(None),
+    weather_render_style: str | None = Form(None),
     # battery
     battery_mode: str | None = Form(None),
 ):
@@ -469,6 +470,8 @@ def api_widget_config_save(
                 wcfg.hourly_interval_hours = max(1, min(24, weather_hourly_interval_hours))
             if weather_daily_days is not None:
                 wcfg.daily_days = max(1, min(14, weather_daily_days))
+            if weather_render_style is not None and weather_render_style in ("classic", "modern"):
+                wcfg.render_style = weather_render_style
     elif widget.widget_type == "battery":
         with widget_locked(db, frame.id, widget.id) as (_, _, bcfg):
             if battery_mode is not None:
@@ -1108,10 +1111,19 @@ def api_widget_preview_weather(
         if wcfg.mode == "multi_city":
             raise HTTPException(400, "No cities added to this widget yet")
         raise HTTPException(400, "No location set on this widget yet")
-    png = weather_render.render_weather_preview_png(
-        wcfg.mode, data, orientation=frame.orientation, palette_rgb=frame.palette_rgb, units=wcfg.units,
-        city_label=wcfg.city_label or "", interval_hours=wcfg.hourly_interval_hours,
-    )
+    if wcfg.render_style == "modern" and wcfg.mode in ("current", "daily"):
+        # Same local-import reasoning as widgets/weather.py's render().
+        from .. import html_render
+
+        png = html_render.render_weather_preview_png(
+            wcfg.mode, data, orientation=frame.orientation, palette_rgb=frame.palette_rgb, units=wcfg.units,
+            city_label=wcfg.city_label or "",
+        )
+    else:
+        png = weather_render.render_weather_preview_png(
+            wcfg.mode, data, orientation=frame.orientation, palette_rgb=frame.palette_rgb, units=wcfg.units,
+            city_label=wcfg.city_label or "", interval_hours=wcfg.hourly_interval_hours,
+        )
     return Response(content=png, media_type="image/png")
 
 

server/app/routers/frame_pages.py

@@ -25,6 +25,7 @@ from ..global_actions import GLOBAL_ACTION_LABELS
 from ..image_pipeline import (
     BORDER_STYLES,
     BORDER_STYLE_LABELS,
+    CALIBRATED_SPECTRA6_RGB,
     DEFAULT_PALETTE_RGB,
     DISPLAY_MODE_LABELS,
     MAX_BORDER_THICKNESS,
@@ -89,6 +90,7 @@ def frame_config_page(frame_id: int, request: Request, db: Session = Depends(get
         timezones=ALL_TIMEZONES,
         palette_labels=PALETTE_LABELS,
         default_palette_rgb=DEFAULT_PALETTE_RGB,
+        calibrated_spectra6_hex=palette_to_hex(CALIBRATED_SPECTRA6_RGB),
         palette_to_hex=palette_to_hex,
         photo_widget_id=photo_widget_id,
         global_action_labels=GLOBAL_ACTION_LABELS,

server/app/static/frame_config.js

@@ -215,6 +215,18 @@ document.getElementById('palette-reset').addEventListener('click', () => {
   savePalette({ palette_reset: 'true', color_boost: '1', contrast_boost: '1', dither_strength: '1' });
 });
 
+// Fills the table with a community-measured starting point (see the
+// card's own explanatory text) -- doesn't save by itself, same as
+// editing the hex/RGB fields by hand; the user still clicks Save (or
+// Reset) to commit or discard it.
+document.getElementById('palette-load-calibrated').addEventListener('click', () => {
+  const inputs = paletteHexInputs();
+  window.CALIBRATED_SPECTRA6_HEX.forEach((hex, i) => {
+    inputs[i].value = hex;
+    syncPaletteFromHex(i);
+  });
+});
+
 // ---- Preview: current photo vs. how it renders with saved settings ----
 // Scoped to this frame's photo widget (window.PHOTO_WIDGET_PREVIEW_API,
 // set by the template) rather than window.FRAME_API -- palette/color/

server/app/static/widget_dialog_weather.js

@@ -14,6 +14,12 @@ function updateWeatherFieldVisibility() {
   document.getElementById('weather-daily-days-row').style.display = mode === 'daily' ? '' : 'none';
   document.getElementById('weather-location-section').style.display = mode === 'multi_city' ? 'none' : '';
   document.getElementById('weather-cities-section').style.display = mode === 'multi_city' ? '' : 'none';
+  // Modern style is only built for current/daily (see app/html_render.py) --
+  // hourly/multi_city always render classic server-side regardless of this
+  // setting, so hide the row entirely rather than offer a choice that's a
+  // silent no-op.
+  document.getElementById('weather-render-style-row').style.display =
+    (mode === 'current' || mode === 'daily') ? '' : 'none';
 }
 
 function addWeatherWidgetCityRow(label) {
@@ -74,6 +80,7 @@ function initWeatherDialog() {
       weather_units: document.getElementById('weather_units').value,
       weather_hourly_interval_hours: document.getElementById('weather_hourly_interval_hours').value,
       weather_daily_days: document.getElementById('weather_daily_days').value,
+      weather_render_style: document.getElementById('weather_render_style').value,
     });
     try {
       const resp = await fetch(`${window.FRAME_API}/config`, {

server/app/templates/_widget_dialog_weather.html

@@ -11,6 +11,14 @@
         <option value="multi_city" {% if weather_cfg.mode == "multi_city" %}selected{% endif %}>Multiple cities</option>
       </select>
     </label>
+    <div id="weather-render-style-row">
+      <label>Render style
+        <select id="weather_render_style">
+          <option value="classic" {% if weather_cfg.render_style == "classic" %}selected{% endif %}>Classic (hand-drawn icons)</option>
+          <option value="modern" {% if weather_cfg.render_style == "modern" %}selected{% endif %}>Modern (experimental, current/daily only)</option>
+        </select>
+      </label>
+    </div>
     <label>Weather source
       <select id="weather_provider">
         {% for value, label in weather_provider_labels.items() %}

server/app/templates/frame_config.html

@@ -187,6 +187,12 @@
 
         <button type="button" class="secondary" id="palette-save" style="margin-top: 16px;">Save</button>
         <button type="button" class="secondary" id="palette-reset">Reset to defaults</button>
+        <button type="button" class="secondary" id="palette-load-calibrated">Load calibrated Spectra 6 preset</button>
+        <p class="sub" style="margin-top: 8px;">Experimental: a community-measured
+          starting point (not this specific panel) -- fills the table above,
+          doesn't save by itself. Real Spectra 6 ink is duller than the
+          idealized defaults; this may or may not match your actual unit.
+          Compare against the physical panel before keeping it.</p>
       </details>
 
       <section class="card">
@@ -221,6 +227,7 @@
   <script>
     window.FRAME_BASE_API = window.FRAME_API = {{ ("/api/frames/" ~ frame.id) | tojson }};
     window.DEFAULT_PALETTE_HEX = {{ palette_to_hex(default_palette_rgb) | tojson }};
+    window.CALIBRATED_SPECTRA6_HEX = {{ calibrated_spectra6_hex | tojson }};
     window.PHOTO_WIDGET_PREVIEW_API = {{ (("/api/frames/" ~ frame.id ~ "/widgets/" ~ photo_widget_id) | tojson) if photo_widget_id else "null" }};
   </script>
   <script src="/static/device_status_bar.js"></script>

server/app/templates/widget_html/weather_current.html.jinja

@@ -0,0 +1,30 @@
+<!doctype html>
+<html><head><style>
+  @font-face { font-family: "Inter"; src: url("file://{{ font_dir }}/Inter-Regular.ttf"); font-weight: 400; }
+  @font-face { font-family: "Inter"; src: url("file://{{ font_dir }}/Inter-Bold.ttf"); font-weight: 700; }
+  * { margin: 0; padding: 0; box-sizing: border-box; font-family: "Inter", sans-serif; }
+  body { width: {{ w }}px; height: {{ h }}px; background: #ffffff; }
+  .card {
+    width: {{ w - gutter * 2 }}px;
+    height: {{ h - gutter * 2 }}px;
+    margin: {{ gutter }}px;
+    border-radius: {{ radius }}px;
+    overflow: hidden;
+    background: #ffffff;
+    display: flex;
+    flex-direction: column;
+    align-items: center;
+    justify-content: center;
+    gap: 10px;
+  }
+  .icon { font-size: {{ icon_size }}px; line-height: 1; filter: drop-shadow(0 3px 4px rgba(0, 0, 0, 0.18)); }
+  .temp { font-weight: 700; font-size: {{ temp_size }}px; color: #17233b; }
+  .city { font-weight: 400; font-size: {{ label_size }}px; color: #5b6674; }
+</style></head>
+<body>
+  <div class="card">
+    <div class="icon">{{ emoji }}</div>
+    <div class="temp">{{ temp }}&deg;{{ unit_suffix }}</div>
+    {% if city_label %}<div class="city">{{ city_label }}</div>{% endif %}
+  </div>
+</body></html>

server/app/templates/widget_html/weather_daily.html.jinja

@@ -0,0 +1,51 @@
+<!doctype html>
+<html><head><style>
+  @font-face { font-family: "Inter"; src: url("file://{{ font_dir }}/Inter-Regular.ttf"); font-weight: 400; }
+  @font-face { font-family: "Inter"; src: url("file://{{ font_dir }}/Inter-Bold.ttf"); font-weight: 700; }
+  * { margin: 0; padding: 0; box-sizing: border-box; font-family: "Inter", sans-serif; }
+  body { width: {{ w }}px; height: {{ h }}px; background: #ffffff; }
+  .card {
+    width: {{ w - gutter * 2 }}px;
+    height: {{ h - gutter * 2 }}px;
+    margin: {{ gutter }}px;
+    border-radius: {{ radius }}px;
+    overflow: hidden;
+    box-shadow: 0 4px 14px rgba(0, 20, 60, 0.25);
+    background: #ffffff;
+  }
+  .header {
+    height: {{ header_h }}px;
+    background: linear-gradient(135deg, {{ accent_start }} 0%, {{ accent_end }} 100%);
+    display: flex;
+    align-items: center;
+    padding: 0 16px;
+  }
+  .header .title { color: #ffffff; font-weight: 700; font-size: {{ title_size }}px; }
+  .body { display: flex; height: calc(100% - {{ header_h }}px); padding: 12px 8px; }
+  .col {
+    flex: 1;
+    display: flex;
+    flex-direction: column;
+    align-items: center;
+    justify-content: center;
+    gap: 5px;
+  }
+  .day { font-weight: 600; font-size: {{ label_size }}px; color: #17233b; }
+  .icon { font-size: {{ icon_size }}px; line-height: 1; }
+  .temps { font-weight: 700; font-size: {{ label_size }}px; color: #17233b; }
+  .temps .low { color: #6b7788; font-weight: 400; }
+</style></head>
+<body>
+  <div class="card">
+    {% if city_label %}<div class="header"><div class="title">{{ city_label }}</div></div>{% endif %}
+    <div class="body">
+      {% for d in days %}
+      <div class="col">
+        <div class="day">{{ d.label }}</div>
+        <div class="icon">{{ d.emoji }}</div>
+        <div class="temps">{{ d.high }}&deg;<span class="low">/{{ d.low }}&deg;{{ unit_suffix }}</span></div>
+      </div>
+      {% endfor %}
+    </div>
+  </div>
+</body></html>

server/app/weather_render.py

@@ -33,23 +33,27 @@ from datetime import date, datetime
 
 from PIL import Image, ImageDraw, ImageFont
 
-from .image_pipeline import DEFAULT_PALETTE_RGB, _apply_manage_overlay, _quantize, draw_text, logical_render_size
+from . import panel_style
+from .image_pipeline import _apply_manage_overlay, _quantize, draw_text, logical_render_size
 
-MARGIN = 20
+# MARGIN carries panel_style.CONTENT_MARGIN's value unchanged (not
+# re-tuned -- every column-width/icon-size calc below was measured
+# against 20px). BG/FG are this module's own cloud-icon fill/outline and
+# fog-line color (see draw_cloud/draw_weather_icon), not a text-emphasis
+# concern -- those live in panel_style (font_bold/font_regular, no MUTED
+# gray -- see its module docstring for why).
+MARGIN = panel_style.CONTENT_MARGIN
 BG = (255, 255, 255)
 FG = (0, 0, 0)
-MUTED = (110, 110, 110)
-RULE = (0, 0, 0)
 
 
 def _ink(palette_rgb: list | None, index: int) -> tuple[int, int, int]:
     """One of this frame's actual panel colors by DEFAULT_PALETTE_RGB
     index (2=yellow, 3=red, 4=blue, 5=green -- 0/1 are black/white,
-    already this module's BG/FG) -- same resolution idiom as
-    calendar_render.py's _event_colors, so a custom palette override
-    (Frame.palette_rgb) still gets its own actual yellow/blue, and every
-    fill stays an exact, ditherless palette match either way."""
-    return tuple((palette_rgb or DEFAULT_PALETTE_RGB)[index])
+    already this module's BG/FG) -- thin wrapper over panel_style.ink
+    (which generalized this same resolution idiom), kept so every
+    draw_weather_icon call site below doesn't need touching."""
+    return panel_style.ink(palette_rgb, index)
 
 
 def draw_cloud(draw: ImageDraw.ImageDraw, cx: float, cy: float, r: float, fill=BG, outline=FG) -> None:
@@ -203,14 +207,17 @@ def _format_hour_label(iso_time: str) -> str:
 
 
 def _fit_font_size(draw: ImageDraw.ImageDraw, texts: list[str], max_width: int, max_size: int,
-                   min_size: int = 9) -> int:
+                   min_size: int = 9, font_loader=panel_style.font_bold) -> int:
     """Largest size <= max_size at which every string in `texts` fits
     within max_width -- used to size a per-column label/temp font against
     the actual column width instead of an icon-radius-derived guess,
     which (e.g. "Tomorrow" vs. "Wed") let long labels overlap into the
-    next column at a large icon size on a narrow column."""
+    next column at a large icon size on a narrow column. Measured against
+    `font_loader` (default Inter Bold -- the wider of the two weights a
+    column actually mixes, a label in Regular and a temp in Bold, so
+    fitting against Bold keeps both safely inside max_width)."""
     for size in range(max_size, min_size - 1, -1):
-        font = ImageFont.load_default(size=size)
+        font = font_loader(size)
         if all(draw.textlength(t, font=font) <= max_width for t in texts):
             return size
     return min_size
@@ -232,29 +239,28 @@ def build_current(entry: dict | None, target_w: int, target_h: int, palette_rgb:
     (callers normally catch that earlier and show a placeholder instead,
     but this degrades to a blank canvas rather than erroring either
     way)."""
-    img = Image.new("RGB", (target_w, target_h), BG)
+    img, draw, (cx0, cy0, cw, ch) = panel_style.card_canvas(target_w, target_h)
     if not entry:
         return img
-    draw = ImageDraw.Draw(img)
 
-    icon_r = max(20, min(target_w, target_h) // 4)
-    cx, cy = target_w // 2, target_h // 2 - icon_r // 2
+    icon_r = max(20, min(cw, ch) // 4)
+    cx, cy = cx0 + cw // 2, cy0 + ch // 2 - icon_r // 2
     draw_weather_icon(draw, cx, cy, icon_r, entry["category"], palette_rgb)
 
     unit_suffix = "F" if units == "fahrenheit" else "C"
-    temp_size = max(24, min(target_w, target_h) // 3)
-    temp_font = ImageFont.load_default(size=temp_size)
+    temp_size = max(24, min(cw, ch) // 3)
+    temp_font = panel_style.font_bold(temp_size)
     temp_text = f"{round(entry['temp'])}°{unit_suffix}"
     bbox = draw.textbbox((0, 0), temp_text, font=temp_font)
     temp_y = cy + icon_r + 12
-    draw_text(img, (target_w // 2 - (bbox[2] - bbox[0]) // 2, temp_y), temp_text, temp_font)
+    draw_text(img, (cx0 + cw // 2 - (bbox[2] - bbox[0]) // 2, temp_y), temp_text, temp_font)
 
     if city_label:
         label_size = max(12, temp_size // 3)
-        label_font = ImageFont.load_default(size=label_size)
+        label_font = panel_style.font_regular(label_size)
         lbbox = draw.textbbox((0, 0), city_label, font=label_font)
-        draw_text(img, (target_w // 2 - (lbbox[2] - lbbox[0]) // 2, temp_y + temp_size + 8),
-                 city_label, label_font, MUTED)
+        draw_text(img, (cx0 + cw // 2 - (lbbox[2] - lbbox[0]) // 2, temp_y + temp_size + 8),
+                 city_label, label_font)
     return img
 
 
@@ -265,19 +271,23 @@ def build_hourly(entries: list[dict], target_w: int, target_h: int, palette_rgb:
     fetch_hourly), each showing an hour label, icon, and temp. Same
     "draw however many fit" graceful degradation as draw_weather_row if
     the box is too narrow for every tick."""
-    img = Image.new("RGB", (target_w, target_h), BG)
-    draw = ImageDraw.Draw(img)
-    text_x0 = MARGIN
-    text_w = target_w - MARGIN * 2
-    y = MARGIN
+    img, draw, (cx0, cy0, cw, ch) = panel_style.card_canvas(target_w, target_h)
+    text_x0 = cx0 + MARGIN
+    text_w = cw - MARGIN * 2
+    y = cy0 + MARGIN
 
-    title_size = max(14, min(target_w, target_h) // 16)
+    title_size = max(14, min(cw, ch) // 16)
     if city_label:
-        title_font = ImageFont.load_default(size=title_size)
-        draw_text(img, (text_x0, y), city_label, title_font)
-        y += title_size + 10
-        draw.line([(text_x0, y), (text_x0 + text_w, y)], fill=RULE)
-        y += 12
+        # A filled header bar (this widget's chosen accent is black, not
+        # a color, so the hand-drawn icons below stay the star -- see
+        # panel_style module docstring) replaces the old plain title +
+        # thin rule line.
+        header_h = title_size + 20
+        panel_style.draw_header_bar(draw, (cx0, cy0, cw, header_h), header_h,
+                                    panel_style.theme_color("weather", palette_rgb))
+        title_font = panel_style.font_bold(title_size)
+        draw_text(img, (text_x0, cy0 + (header_h - title_size) // 2), city_label, title_font, BG)
+        y = cy0 + header_h + 12
 
     # Capped to however many columns actually fit at a legible width
     # (narrower widgets/smaller intervals just show fewer ticks) rather
@@ -290,23 +300,24 @@ def build_hourly(entries: list[dict], target_w: int, target_h: int, palette_rgb:
     if not ticks:
         return img
     col_w = max(1, text_w // len(ticks))
-    icon_r = max(10, min(col_w // 3, (target_h - y - MARGIN) // 4))
+    icon_r = max(10, min(col_w // 3, (cy0 + ch - y - MARGIN) // 4))
     unit_suffix = "F" if units == "fahrenheit" else "C"
     time_labels = [_format_hour_label(e["time"]) for e in ticks]
     temp_labels = [f"{round(e['temp'])}°{unit_suffix}" for e in ticks]
     label_size = _fit_font_size(draw, time_labels + temp_labels, col_w - 6, max_size=icon_r)
-    label_font = ImageFont.load_default(size=label_size)
+    time_font = panel_style.font_regular(label_size)
+    temp_font = panel_style.font_bold(label_size)
 
     for i, entry in enumerate(ticks):
         cx = text_x0 + i * col_w + col_w // 2
         time_label = time_labels[i]
-        tbbox = draw.textbbox((0, 0), time_label, font=label_font)
-        draw_text(img, (cx - (tbbox[2] - tbbox[0]) // 2, y), time_label, label_font, MUTED)
+        tbbox = draw.textbbox((0, 0), time_label, font=time_font)
+        draw_text(img, (cx - (tbbox[2] - tbbox[0]) // 2, y), time_label, time_font)
         cy = y + label_size + 10 + icon_r
         draw_weather_icon(draw, cx, cy, icon_r, entry["category"], palette_rgb)
         temp_label = temp_labels[i]
-        tempbbox = draw.textbbox((0, 0), temp_label, font=label_font)
-        draw_text(img, (cx - (tempbbox[2] - tempbbox[0]) // 2, cy + icon_r + 6), temp_label, label_font)
+        tempbbox = draw.textbbox((0, 0), temp_label, font=temp_font)
+        draw_text(img, (cx - (tempbbox[2] - tempbbox[0]) // 2, cy + icon_r + 6), temp_label, temp_font)
     return img
 
 
@@ -317,40 +328,41 @@ def build_daily(daily: dict[str, dict], target_w: int, target_h: int, palette_rg
     configured day count by app/weather's provider fetch_daily -- this
     just draws whatever it's handed, same "stop once it doesn't fit"
     graceful degradation as draw_weather_row)."""
-    img = Image.new("RGB", (target_w, target_h), BG)
-    draw = ImageDraw.Draw(img)
-    text_x0 = MARGIN
-    text_w = target_w - MARGIN * 2
-    y = MARGIN
+    img, draw, (cx0, cy0, cw, ch) = panel_style.card_canvas(target_w, target_h)
+    text_x0 = cx0 + MARGIN
+    text_w = cw - MARGIN * 2
+    y = cy0 + MARGIN
 
-    title_size = max(14, min(target_w, target_h) // 16)
+    title_size = max(14, min(cw, ch) // 16)
     if city_label:
-        title_font = ImageFont.load_default(size=title_size)
-        draw_text(img, (text_x0, y), city_label, title_font)
-        y += title_size + 10
-        draw.line([(text_x0, y), (text_x0 + text_w, y)], fill=RULE)
-        y += 12
+        header_h = title_size + 20
+        panel_style.draw_header_bar(draw, (cx0, cy0, cw, header_h), header_h,
+                                    panel_style.theme_color("weather", palette_rgb))
+        title_font = panel_style.font_bold(title_size)
+        draw_text(img, (text_x0, cy0 + (header_h - title_size) // 2), city_label, title_font, BG)
+        y = cy0 + header_h + 12
 
     days = list(daily.items())
     if not days:
         return img
     col_w = max(1, text_w // len(days))
-    icon_r = max(12, min(col_w // 3, (target_h - y - MARGIN) // 4))
+    icon_r = max(12, min(col_w // 3, (cy0 + ch - y - MARGIN) // 4))
     unit_suffix = "F" if units == "fahrenheit" else "C"
     labels = [_day_label(date.fromisoformat(day_str)) for day_str, _ in days]
     temps_strs = [f"{round(d['high'])}°/{round(d['low'])}°{unit_suffix}" for _, d in days]
     label_size = _fit_font_size(draw, labels + temps_strs, col_w - 6, max_size=icon_r)
-    label_font = ImageFont.load_default(size=label_size)
+    label_font = panel_style.font_regular(label_size)
+    temp_font = panel_style.font_bold(label_size)
 
     for i, (_, d) in enumerate(days):
         x0 = text_x0 + i * col_w
         label, temps = labels[i], temps_strs[i]
         lbbox = draw.textbbox((0, 0), label, font=label_font)
-        draw_text(img, (x0 + col_w // 2 - (lbbox[2] - lbbox[0]) // 2, y), label, label_font, MUTED)
+        draw_text(img, (x0 + col_w // 2 - (lbbox[2] - lbbox[0]) // 2, y), label, label_font)
         cx, cy = x0 + col_w // 2, y + label_size + 10 + icon_r
         draw_weather_icon(draw, cx, cy, icon_r, d["category"], palette_rgb)
-        tbbox = draw.textbbox((0, 0), temps, font=label_font)
-        draw_text(img, (cx - (tbbox[2] - tbbox[0]) // 2, cy + icon_r + 8), temps, label_font)
+        tbbox = draw.textbbox((0, 0), temps, font=temp_font)
+        draw_text(img, (cx - (tbbox[2] - tbbox[0]) // 2, cy + icon_r + 8), temps, temp_font)
     return img
 
 
@@ -360,10 +372,9 @@ def build_multi_city(cities: list[dict], target_w: int, target_h: int, palette_r
     reuses draw_weather_row (the same layout calendar_render.py's
     embedded strip uses), just as the whole widget's own content instead
     of a strip above an agenda day."""
-    img = Image.new("RGB", (target_w, target_h), BG)
+    img, draw, (cx0, cy0, cw, ch) = panel_style.card_canvas(target_w, target_h)
     if not cities:
         return img
-    draw = ImageDraw.Draw(img)
     # Just the city name on-panel ("Portland", not the full disambiguated
     # "Portland, Oregon, United States") -- that fuller form matters for
     # telling apart geocoder candidates when adding a city (see
@@ -372,7 +383,7 @@ def build_multi_city(cities: list[dict], target_w: int, target_h: int, palette_r
     # calendar_render.py's _weather_for_day already does for its own
     # embedded strip.
     cities = [{**c, "label": c["label"].split(",")[0].strip()} for c in cities]
-    text_w = target_w - MARGIN * 2
+    text_w = cw - MARGIN * 2
     # Sized against how many entries actually need to fit side by side,
     # not just the box's height -- an icon/font picked from target_h
     # alone (as this used to do) drew each entry so wide that only the
@@ -380,13 +391,14 @@ def build_multi_city(cities: list[dict], target_w: int, target_h: int, palette_r
     # doesn't fit" degradation silently dropped every city after it,
     # even in an ordinary-sized widget with plenty of cities configured.
     col_w = max(1, text_w // len(cities))
-    icon_r = max(10, min(col_w // 6, target_h // 6, 40))
+    icon_r = max(10, min(col_w // 6, ch // 6, 40))
     unit_suffix = "F" if units == "fahrenheit" else "C"
     labels = [f"{c['label']} {round(c['high'])}°/{round(c['low'])}°{unit_suffix}" for c in cities]
-    font_size = _fit_font_size(draw, labels, col_w - (icon_r * 2 + 24), max_size=icon_r)
-    font = ImageFont.load_default(size=font_size)
-    y = max(MARGIN, (target_h - (icon_r * 2 + 8)) // 2)
-    draw_weather_row(img, draw, MARGIN, y, text_w, cities, icon_r=icon_r, font=font, units=units,
+    font_size = _fit_font_size(draw, labels, col_w - (icon_r * 2 + 24), max_size=icon_r,
+                               font_loader=panel_style.font_regular)
+    font = panel_style.font_regular(font_size)
+    y = max(cy0 + MARGIN, cy0 + (ch - (icon_r * 2 + 8)) // 2)
+    draw_weather_row(img, draw, cx0 + MARGIN, y, text_w, cities, icon_r=icon_r, font=font, units=units,
                      show_labels=True, palette_rgb=palette_rgb)
     return img
 

server/app/widgets/_shared.py

@@ -7,17 +7,19 @@ fraction of the panel, so its placeholder needs to scale down with it.
 
 from __future__ import annotations
 
-from PIL import Image, ImageDraw, ImageFont
+from PIL import Image, ImageDraw
 
-_BG = (245, 245, 245)
-_FG = (90, 90, 90)
+from .. import panel_style
+from ..image_pipeline import draw_text
+
+_BG = (255, 255, 255)
 
 
 def placeholder_image(target_w: int, target_h: int, lines: list[str]) -> Image.Image:
     img = Image.new("RGB", (target_w, target_h), _BG)
     draw = ImageDraw.Draw(img)
     font_size = max(10, min(20, target_h // 8))
-    font = ImageFont.load_default(size=font_size)
+    font = panel_style.font_regular(font_size)
     line_h = font_size + 4
     total_h = line_h * len(lines)
     y = max(4, (target_h - total_h) // 2)
@@ -25,6 +27,6 @@ def placeholder_image(target_w: int, target_h: int, lines: list[str]) -> Image.I
         bbox = draw.textbbox((0, 0), line, font=font)
         line_w = bbox[2] - bbox[0]
         x = max(4, (target_w - line_w) // 2)
-        draw.text((x, y), line, fill=_FG, font=font)
+        draw_text(img, (x, y), line, font)
         y += line_h
     return img

server/app/widgets/battery.py

@@ -17,10 +17,11 @@ from __future__ import annotations
 import io
 import time
 
-from PIL import Image, ImageDraw, ImageFont
+from PIL import Image, ImageDraw
 from sqlalchemy.orm import Session
 
-from ..image_pipeline import DEFAULT_PALETTE_RGB, _quantize, draw_text, logical_render_size
+from .. import panel_style
+from ..image_pipeline import _quantize, draw_text, logical_render_size
 from ..models import BatteryWidgetConfig, Frame, Widget
 from ..routers.common import battery_estimate_s
 from ._shared import placeholder_image
@@ -28,45 +29,16 @@ from ._shared import placeholder_image
 ACTIONS: dict = {}
 ACTION_LABELS: dict[str, str] = {}
 
-BG = (255, 255, 255)
-MUTED = (110, 110, 110)
 
-# Same thresholds/colors as manage_overlay.py's own battery glyph (not
-# shared code -- that one draws onto the manage-QR overlay in a fixed
-# small size, this one fills an arbitrary widget region -- but the
-# "how worried should I be" color story should read the same wherever a
-# battery glyph shows up on a panel). Exact panel ink RGB values, not
-# arbitrary reds/yellows/greens -- a flat fill already at a palette
-# color quantizes with zero dithering error once the whole composited
-# canvas gets quantized, where an off-palette color would dither into a
-# visible speckle at these small on-panel sizes.
-_LOW = DEFAULT_PALETTE_RGB[3]  # red
-_MEDIUM = DEFAULT_PALETTE_RGB[2]  # yellow
-_HIGH = DEFAULT_PALETTE_RGB[5]  # green
-
-
-def _fill_color(percent: int) -> tuple[int, int, int]:
-    if percent <= 15:
-        return _LOW
-    if percent <= 40:
-        return _MEDIUM
-    return _HIGH
-
-
-def _draw_icon(draw: ImageDraw.ImageDraw, cx: int, top: int, icon_w: int, icon_h: int, percent: int) -> None:
-    stroke = max(2, icon_h // 12)
+def _draw_icon(draw: ImageDraw.ImageDraw, cx: int, top: int, icon_w: int, icon_h: int, percent: int,
+              palette_rgb: list | None = None) -> None:
+    """Centers panel_style.draw_battery_icon (top-left-anchored) under
+    `cx` -- this widget's own layout picks a center point, that helper's
+    shared implementation (also used by manage_overlay.py's battery
+    readout) just needs a top-left corner."""
     nub_w = max(3, icon_w // 10)
-    nub_h = icon_h // 2
     x0 = cx - (icon_w + nub_w) // 2
-    y0 = top
-    inner_x0, inner_y0 = x0 + stroke, y0 + stroke
-    inner_x1, inner_y1 = x0 + icon_w - stroke, y0 + icon_h - stroke
-    fill_x1 = inner_x0 + round((inner_x1 - inner_x0) * (max(0, min(100, percent)) / 100))
-    if fill_x1 > inner_x0:
-        draw.rectangle([inner_x0, inner_y0, fill_x1, inner_y1], fill=_fill_color(percent))
-    draw.rectangle([x0, y0, x0 + icon_w, y0 + icon_h], outline=(0, 0, 0), width=stroke)
-    nub_y = y0 + (icon_h - nub_h) // 2
-    draw.rectangle([x0 + icon_w, nub_y, x0 + icon_w + nub_w, nub_y + nub_h], fill=(0, 0, 0))
+    panel_style.draw_battery_icon(draw, x0, top, icon_w, icon_h, percent, palette_rgb)
 
 
 def _format_estimate(seconds: float) -> str:
@@ -99,22 +71,26 @@ def render(db: Session, frame: Frame, widget: Widget, target_w: int, target_h: i
 
     cfg = db.get(BatteryWidgetConfig, widget.id)
     mode = cfg.mode if cfg else "detailed"
+    palette_rgb = frame.palette_rgb
 
-    img = Image.new("RGB", (target_w, target_h), BG)
-    draw = ImageDraw.Draw(img)
-    cx = target_w // 2
+    img, draw, (cx0, cy0, cw, ch) = panel_style.card_canvas(target_w, target_h)
+    cx = cx0 + cw // 2
 
-    icon_h = max(20, min(target_w, target_h) // 3)
+    icon_h = max(20, min(cw, ch) // 3)
     icon_w = int(icon_h * 1.8)
-    icon_top = max(4, target_h // 8)
-    _draw_icon(draw, cx, icon_top, icon_w, icon_h, percent)
+    icon_top = max(4, cy0 + ch // 8)
+    _draw_icon(draw, cx, icon_top, icon_w, icon_h, percent, palette_rgb)
 
-    pct_font_size = max(18, min(target_w, target_h) // 3)
-    pct_font = ImageFont.load_default(size=pct_font_size)
+    # The percent number picks up the icon's own charge-level color
+    # (red/yellow/green) instead of plain black -- ties the two into one
+    # visual statement rather than "colored icon, black number".
+    pct_font_size = max(18, min(cw, ch) // 3)
+    pct_font = panel_style.font_bold(pct_font_size)
     pct_text = f"{percent}%"
     bbox = draw.textbbox((0, 0), pct_text, font=pct_font)
     pct_y = icon_top + icon_h + 10
-    draw_text(img, (cx - (bbox[2] - bbox[0]) // 2, pct_y), pct_text, pct_font)
+    draw_text(img, (cx - (bbox[2] - bbox[0]) // 2, pct_y), pct_text, pct_font,
+             panel_style.battery_fill_color(percent, palette_rgb))
 
     if mode == "detailed":
         lines = []
@@ -125,13 +101,13 @@ def render(db: Session, frame: Frame, widget: Widget, target_w: int, target_h: i
             lines.append(f"Reported {_format_age(frame.battery_as_of)}")
 
         small_font_size = max(11, pct_font_size // 3)
-        small_font = ImageFont.load_default(size=small_font_size)
+        small_font = panel_style.font_regular(small_font_size)
         y = pct_y + pct_font_size + 12
         for line in lines:
-            if y + small_font_size > target_h - 4:
+            if y + small_font_size > cy0 + ch - 4:
                 break
             lbbox = draw.textbbox((0, 0), line, font=small_font)
-            draw_text(img, (cx - (lbbox[2] - lbbox[0]) // 2, y), line, small_font, MUTED)
+            draw_text(img, (cx - (lbbox[2] - lbbox[0]) // 2, y), line, small_font)
             y += small_font_size + 6
 
     return img

server/app/widgets/weather.py

@@ -1,9 +1,12 @@
 """Weather widget: one of four display modes (see models.
 WeatherWidgetConfig) backed by a pluggable provider (app/weather/'s
 PROVIDERS registry -- Open-Meteo or NWS) and drawn by app/weather_render.
-py's build() dispatch. No real "next"/"back" concept (same as
-whiteboard) -- a single "check now" action forces a re-fetch bypassing
-the normal throttle."""
+py's build() dispatch -- or, for "current"/"daily" modes with
+render_style="modern", by app/html_render.py's Jinja2/headless-Chromium
+renderer instead (experimental; hourly/multi_city always render classic
+regardless of render_style, see html_render's module docstring). No real
+"next"/"back" concept (same as whiteboard) -- a single "check now"
+action forces a re-fetch bypassing the normal throttle."""
 
 from __future__ import annotations
 
@@ -27,6 +30,18 @@ def render(db: Session, frame: Frame, widget: Widget, target_w: int, target_h: i
     data = get_or_refresh_weather_widget_data(db, frame, widget)
     if data is None:
         return placeholder_image(target_w, target_h, ["Weather widget", "not configured yet"])
+
+    if cfg.render_style == "modern" and cfg.mode in ("current", "daily"):
+        # Local import: html_render pulls in Playwright, a real headless-
+        # Chromium dependency -- every other widget type, and this one's
+        # own classic/hourly/multi_city paths, should never pay for it
+        # (same reasoning as image_pipeline.render_placeholder's local
+        # `import qrcode`).
+        from .. import html_render
+
+        return html_render.build(cfg.mode, data, target_w, target_h, frame.palette_rgb, cfg.units,
+                                 city_label=cfg.city_label or "")
+
     return weather_render.build(
         cfg.mode, data, target_w, target_h, frame.palette_rgb, cfg.units,
         city_label=cfg.city_label or "", interval_hours=cfg.hourly_interval_hours,

server/requirements.txt

@@ -11,3 +11,5 @@ icalendar==7.2.2
 recurring-ical-events==3.8.2
 caldav==3.2.1
 pypdfium2==5.12.1
+playwright==1.61.0
+numpy==2.5.1

server/tests/test_migrations.py

@@ -93,6 +93,7 @@ def test_expected_columns_exist_on_current_schema():
     assert "ix_frame_button_actions_widget_button" in button_action_indexes  # migration 28
     assert {"hold_duration_ms", "next_hold_action", "back_hold_action", "last_cycled_layout_id"} <= frame_columns
     assert {"last_displayed_image", "last_displayed_at"} <= frame_columns  # migration 30
+    assert "render_style" in weather_widget_columns  # migration 31
 
 
 # --- widget system backfill (migration 16 + _ensure_widgets_backfilled) ---

server/tests/test_saved_layouts.py

@@ -27,6 +27,7 @@ from app.models import (
     TaskWidgetConfig,
     User,
     Widget,
+    WeatherWidgetConfig,
 )
 
 from .conftest import csrf_headers, link_user, login, make_user
@@ -56,6 +57,16 @@ def _add_tasks_widget(db_session, frame_id=1, x=3, y=0, w=2, h=2, sort_order=2)
     return widget
 
 
+def _add_weather_widget(db_session, frame_id=1, x=0, y=0, w=2, h=2, sort_order=1) -> Widget:
+    widget = Widget(frame_id=frame_id, widget_type="weather", x=x, y=y, w=w, h=h,
+                    sort_order=sort_order, created_at=time.time())
+    db_session.add(widget)
+    db_session.flush()
+    db_session.add(WeatherWidgetConfig(widget_id=widget.id))
+    db_session.commit()
+    return widget
+
+
 def _setup_alice(client) -> None:
     resp = client.post("/setup", data={"username": "alice", "password": "hunter22"})
     assert resp.status_code == 303, resp.text
@@ -89,6 +100,48 @@ def test_save_captures_placement_and_photo_settings_but_not_queue_state(client,
                            "queue_target_len": 30}
 
 
+def test_save_and_apply_round_trip_weather_settings(client, db_session):
+    _setup_alice(client)
+    weather = _add_weather_widget(db_session)
+    with db_session.no_autoflush:
+        wcfg = db_session.get(WeatherWidgetConfig, weather.id)
+        wcfg.mode = "daily"
+        wcfg.provider = "nws"
+        wcfg.units = "celsius"
+        wcfg.city_label = "Boston, MA"
+        wcfg.city_latitude = 42.36
+        wcfg.city_longitude = -71.06
+        wcfg.hourly_interval_hours = 6
+        wcfg.daily_days = 7
+        wcfg.checked_at = 12345.0
+        wcfg.cached = {"stale": "runtime state, not a setting"}
+    db_session.commit()
+    db_session.expunge(wcfg)
+
+    save_resp = client.post("/api/frames/1/layouts", json={"name": "Weather Layout"}, headers=csrf_headers(client))
+    assert save_resp.status_code == 200, save_resp.text
+    layout = db_session.query(SavedLayout).filter_by(user_id=1, name="Weather Layout").one()
+    snap = db_session.query(SavedLayoutWidget).filter_by(saved_layout_id=layout.id, widget_type="weather").one()
+    assert snap.config == {
+        "mode": "daily", "provider": "nws", "units": "celsius", "city_label": "Boston, MA",
+        "city_latitude": 42.36, "city_longitude": -71.06, "hourly_interval_hours": 6, "daily_days": 7,
+        "cities": None, "render_style": "classic",
+    }
+
+    client.delete("/api/frames/1/widgets", headers=csrf_headers(client))
+    apply_resp = client.post(f"/api/frames/1/layouts/{layout.id}/apply", headers=csrf_headers(client))
+    assert apply_resp.status_code == 200, apply_resp.text
+
+    new_widget = db_session.query(Widget).filter_by(frame_id=1, widget_type="weather").one()
+    new_cfg = db_session.get(WeatherWidgetConfig, new_widget.id)
+    assert (new_cfg.mode, new_cfg.provider, new_cfg.units) == ("daily", "nws", "celsius")
+    assert (new_cfg.city_label, new_cfg.city_latitude, new_cfg.city_longitude) == ("Boston, MA", 42.36, -71.06)
+    assert (new_cfg.hourly_interval_hours, new_cfg.daily_days) == (6, 7)
+    # Runtime fetch-cache state is never captured/restored by a saved layout.
+    assert new_cfg.checked_at == 0.0
+    assert new_cfg.cached is None
+
+
 def test_save_captures_calendar_sources_and_button_actions(client, db_session):
     _setup_alice(client)
     db_session.query(Widget).filter_by(frame_id=1, widget_type="photos").delete()

server/tests/test_widget_config_and_queue_endpoints.py

@@ -243,6 +243,35 @@ def test_config_save_switching_mode_clears_the_now_incompatible_cache(client, db
     assert resp.status_code == 200, resp.text
 
 
+def test_preview_weather_honors_modern_render_style(client, db_session, monkeypatch):
+    """Regression test: api_widget_preview_weather originally called
+    weather_render.render_weather_preview_png directly, unconditionally --
+    the dialog's own live preview never reflected render_style="modern" at
+    all, even though the real device-facing render (widgets/weather.py's
+    render()) did. Route through html_render instead for modern/current or
+    modern/daily, same as the device path -- assert it's actually reached,
+    not just that the request 200s (it would 200 either way if this
+    silently fell back to classic)."""
+    client.post("/setup", data={"username": "alice", "password": "hunter22"})
+    widget = _add_weather_widget(db_session, mode="current", render_style="modern")
+    monkeypatch.setattr(
+        "app.routers.api_widgets.get_or_refresh_weather_widget_data",
+        lambda db, frame, widget, force=False: {"temp": 72.0, "category": "clear"},
+    )
+    calls = []
+
+    def _fake_render_html_to_image(html, target_w, target_h):
+        calls.append((target_w, target_h))
+        return Image.new("RGB", (target_w, target_h), (255, 255, 255))
+
+    monkeypatch.setattr("app.html_render.render_html_to_image", _fake_render_html_to_image)
+
+    resp = client.get(f"/api/frames/1/widgets/{widget.id}/preview/weather")
+    assert resp.status_code == 200, resp.text
+    assert resp.headers["content-type"] == "image/png"
+    assert calls, "html_render.render_html_to_image was never called -- preview endpoint didn't honor render_style"
+
+
 def test_config_save_truncates_an_overlong_tasks_name(client, db_session):
     client.post("/setup", data={"username": "alice", "password": "hunter22"})
     widget = _add_tasks_widget(db_session)

server/tests/test_widgets_weather.py

@@ -11,7 +11,9 @@ from __future__ import annotations
 
 import time
 
-from app import grid, widgets
+from PIL import Image
+
+from app import grid, html_render, widgets
 from app.models import Frame, WeatherWidgetConfig, Widget
 
 
@@ -109,3 +111,79 @@ def test_check_now_forces_a_refetch(db_session, monkeypatch):
 def test_action_labels():
     assert set(widgets.weather.ACTIONS.keys()) == {"check_now"}
     assert widgets.weather.ACTION_LABELS == {"check_now": "Check for updates"}
+
+
+# --- render_style="modern" (app/html_render.py) -------------------------
+# No real browser here -- html_render.render_html_to_image is monkeypatched
+# to a stub, so these tests exercise weather.py's dispatch + html_render's
+# own template-rendering/ordered_dither logic, not Playwright/Chromium
+# itself (that needs a real browser install -- see the run-server-driven
+# manual verification these tests don't replace).
+
+def _stub_render_html_to_image(monkeypatch, fill=(10, 20, 200)):
+    def _stub(html, target_w, target_h):
+        return Image.new("RGB", (target_w, target_h), fill)
+
+    monkeypatch.setattr(html_render, "render_html_to_image", _stub)
+
+
+def test_render_modern_current_mode(db_session, monkeypatch):
+    frame, widget = _make_widget(db_session, mode="current", city_label="Portland", render_style="modern")
+    monkeypatch.setattr(widgets.weather, "get_or_refresh_weather_widget_data",
+                        lambda db, frame, widget: {"temp": 72.0, "category": "clear"})
+    _stub_render_html_to_image(monkeypatch)
+
+    img = widgets.weather.render(db_session, frame, widget, 300, 200)
+    assert img.size == (300, 200)
+    assert img.mode == "RGB"
+
+
+def test_render_modern_daily_mode(db_session, monkeypatch):
+    frame, widget = _make_widget(db_session, mode="daily", city_label="Denver", daily_days=5, render_style="modern")
+    daily = {f"2026-07-{27 + i}": {"high": 70 + i, "low": 50 + i, "category": "clear"} for i in range(5)}
+    monkeypatch.setattr(widgets.weather, "get_or_refresh_weather_widget_data", lambda db, frame, widget: daily)
+    _stub_render_html_to_image(monkeypatch)
+
+    img = widgets.weather.render(db_session, frame, widget, 400, 300)
+    assert img.size == (400, 300)
+    assert img.mode == "RGB"
+
+
+def test_render_modern_ordered_dither_is_exact_palette(db_session, monkeypatch):
+    """The whole point of doing ordered dithering inside html_render (see
+    its module docstring) is that its output is already exact palette
+    colors before the shared whole-canvas Floyd-Steinberg pass ever sees
+    it -- assert that directly, not just "an image came back"."""
+    frame, widget = _make_widget(db_session, mode="current", render_style="modern")
+    monkeypatch.setattr(widgets.weather, "get_or_refresh_weather_widget_data",
+                        lambda db, frame, widget: {"temp": 72.0, "category": "clear"})
+    # A mid-gray fill is nowhere near any of DEFAULT_PALETTE_RGB's 6 exact
+    # colors -- if ordered_dither's nearest-palette-match ran, every pixel
+    # must land on one of them regardless.
+    _stub_render_html_to_image(monkeypatch, fill=(128, 128, 128))
+
+    img = widgets.weather.render(db_session, frame, widget, 120, 100)
+    from app.image_pipeline import DEFAULT_PALETTE_RGB
+
+    palette = set(DEFAULT_PALETTE_RGB)
+    assert set(img.getdata()) <= palette
+
+
+def test_render_modern_falls_back_to_classic_for_hourly_and_multi_city(db_session, monkeypatch):
+    """hourly/multi_city have no "modern" template yet (see html_render's
+    module docstring) -- render_style="modern" on those modes must still
+    produce the classic PIL render, not error or silently do nothing.
+    Deliberately does NOT stub html_render, so this also proves the
+    classic path never imports it for these modes."""
+    frame, widget = _make_widget(db_session, mode="multi_city", render_style="modern")
+    cities = [{"label": "Portland, Oregon, United States", "high": 75, "low": 55, "category": "clear"}]
+    monkeypatch.setattr(widgets.weather, "get_or_refresh_weather_widget_data", lambda db, frame, widget: cities)
+
+    img = widgets.weather.render(db_session, frame, widget, 400, 300)
+    assert img.size == (400, 300)
+
+
+def test_render_style_default_is_classic(db_session, monkeypatch):
+    frame, widget = _make_widget(db_session, mode="current")
+    cfg = db_session.get(WeatherWidgetConfig, widget.id)
+    assert cfg.render_style == "classic"