Animations, GIFs and the globe now move for every reader

decePub no longer looks at the system's "reduce motion" setting, so everything moves the same way whatever it says:
- a GIF video in a post plays by itself, muted and looping, instead of waiting for a tap; it now also starts on a page
  just opened, before the first tap, where the browser used to hold it still;
- animated custom emoji move in the emoji picker instead of showing a still picture;
- the globe turns by itself while no located post is in view, flies to the posts, and its pulses, arcs and Sun move;
- going back to the top of a feed scrolls smoothly;
- tooltips, dropdowns, menus, folding sections, toasts, loading spinners, placeholders, progress bars, radio buttons
  and ratings keep their animations: the build now takes daisyUI's reduce-motion rules out of the stylesheet
  (tools/css/motion.py, run after every Tailwind build, in watch mode too).

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01W4YtEKqxKjKyHkFzuRVMNA

CLAUDE.md

@@ -80,6 +80,10 @@ without network access. NuGet restore still uses nuget.org.
 - `IncludeTailwindOutput` adds the generated file to `Content` before static web assets are resolved. Without that, a
   clean-clone publish would ship `app.css` without its `.gz`/`.br` copies and outside `service-worker-assets.js`.
   The deploy workflow checks for `css/app.css.gz`.
+- Right after Tailwind writes `app.css`, `tools/css/motion.py` (run by `TailwindCompile` and by `tailwind.sh build` and
+  `watch`) deletes the blocks daisyUI emits for `prefers-reduced-motion: reduce` and unwraps its `no-preference` ones,
+  so its transitions and animations play for everyone. It fails the build on a query it cannot rewrite. It needs
+  `python3`.
 - `bash tools/tailwind.sh watch` rebuilds the CSS live next to `dotnet watch`.
 - Tailwind scans every file `.gitignore` doesn't exclude (minus `tools/` and `wwwroot/vendor/`), and only
   generates the classes it finds written out **whole**. Never build a class name by concatenation or interpolation (`"btn-" + size`, `$"btn-{size}"`). Write
@@ -355,7 +359,9 @@ Never redeclare the base's members in a component.
   paints any `[data-blurhash]`: a picture's until it loads, again when its source changes, and for good behind the
   sensitive-media button), a picture's focal point (`object-position`), and an event's online link, participants and
   status. A picture, video or sound that fails to load says "Media unavailable" with "Open original"
-  (`data-media-unavailable`), and a gifv plays only on a tap under `prefers-reduced-motion`.
+  (`data-media-unavailable`), and a gifv plays by itself, muted and looping, for every reader. Blazor writes `muted`
+  only as an attribute, which leaves the video unmuted and Chromium refuses to autoplay it before the reader's first
+  tap, so `main.js` sets the `muted` property of every video carrying the attribute on its `loadstart`.
 - **About** (`Pages/About.razor` at `/about`, no sign-in, `data-about`; linked from NavMenu as `data-nav-about` and from
   Login as `data-about-offer`): the server's name (`data-about-title`), short description and thumbnail, its long
   description (`data-about-description`, `/api/v1/instance/extended_description`), contact (`data-about-contact`), rules
@@ -612,11 +618,11 @@ Never redeclare the base's members in a component.
     quick choices (`Quick`), the server's emoji by category (none first) and common unicode ones by group
     (`Helpers/UnicodeEmojis.cs`, single emoji only, searched by their Mastodon/GitHub shortcode and a few words). Each
     choice is `data-emoji-choice` (the shortcode, or the character) and goes to `OnPick` as `:shortcode:` or the
-    character; it closes the picker first. A GIF shows its still picture under `prefers-reduced-motion`. The card's React
-    button (`data-react`) and the announcements banner's (`data-announcement-react`) react with it, after their quick
-    reactions; the composer's emoji button writes it where the caret is, replacing a selection, else at the end, a
-    shortcode with a space on each side where a letter would touch it (`AppStatusService.CaretOf` / `PlaceCaret`,
-    `main.js`'s `caretOf` and `placeCaret`).
+    character; it closes the picker first. An animated emoji moves in the picker for every reader (its `url`, never its
+    `static_url`). The card's React button (`data-react`) and the announcements banner's (`data-announcement-react`)
+    react with it, after their quick reactions; the composer's emoji button writes it where the caret is, replacing a
+    selection, else at the end, a shortcode with a space on each side where a letter would touch it
+    (`AppStatusService.CaretOf` / `PlaceCaret`, `main.js`'s `caretOf` and `placeCaret`).
   - **Suggestions:** in the composer, `:` and two letters or more at the end of the words offer the matching emoji
     (shortcodes starting with it first, eight at most) among the mention and hashtag suggestions, as
     `data-emoji-suggestion="{shortcode}"`; one picked is written `:shortcode: `.
@@ -765,8 +771,8 @@ Never redeclare the base's members in a component.
 - **The globe** (`wwwroot/js/globe.js`, an ES module imported by `GlobePanel`) runs on globe.gl, vendored in
   `wwwroot/vendor/globe/` with its textures and `countries.json` (`SOURCES.md` has versions, licences and hashes; the
   service worker never precaches it). It looks at the spherical mean of the located posts in view, pulses and draws an
-  arc to a hovered post, honours `prefers-reduced-motion`, and draws only while something moves (idle, it costs no GPU
-  time; `wake()` before anything that animates).
+  arc to a hovered post, moves the same way for every reader (camera flights, the Sun, pulses, arcs, auto-rotation),
+  and draws only while something moves (idle, it costs no GPU time; `wake()` before anything that animates).
   - **Map.** Each pixel computes its own map coordinates from its point on the sphere (`sharpen`), so the poles don't
     pinch; the maps wrap horizontally and get 8× anisotropic filtering (`keepSharp`). The day texture is NASA's, its
     seam repaired by `tools/globe/prepare-day-texture.py` (dev-only, needs Pillow).
@@ -978,6 +984,9 @@ The nginx vhost and headers are in `deploy/nginx/` (it sends `X-Robots-Tag: noin
 
 ## Conventions
 
+- **Motion plays for everyone** (owner, 9 November 2026): nothing reads `prefers-reduced-motion` or any equivalent
+  (`matchMedia`, `motion-safe:`/`motion-reduce:`, a flag fed from it), so animations, GIFs and gifvs, smooth scrolling
+  and the globe behave the same for every reader.
 - Indent with tabs.
 - `Nullable` is disabled and `ImplicitUsings` is enabled.
 - Global Razor usings are in `_Imports.razor`.

Components/Content.razor

@@ -907,8 +907,7 @@
 			<img alt="@media.Description" title="@media.Description" loading="lazy" class="w-full rounded-lg object-cover @(several ? "aspect-square" : "max-h-[60vh]")"
 				 src="@(media.PreviewUrl ?? media.Url)" data-blurhash="@media.Blurhash" style="@FocalPoint(media)" @onerror="() => unavailableMedia.Add(media.Id)" />
 		</button>,
-		// under reduced motion a gifv waits for a tap (its controls)
-		"gifv" => @<video class="w-full rounded-lg" autoplay="@(!CascadingState.Status.PrefersReducedMotion())" controls="@CascadingState.Status.PrefersReducedMotion()" muted loop
+		"gifv" => @<video class="w-full rounded-lg" autoplay muted loop
 						  playsinline poster="@media.PreviewUrl" title="@media.Description" src="@media.Url" @onerror="() => unavailableMedia.Add(media.Id)"></video>,
 		"video" => @<video class="w-full max-h-[50vh] aspect-video rounded-lg neo-inset neo-2xs" controls playsinline preload="metadata"
 						  poster="@media.PreviewUrl" title="@media.Description" src="@media.Url" @onerror="() => unavailableMedia.Add(media.Id)"></video>,

Components/EmojiPicker.razor

@@ -53,7 +53,7 @@
 											 OnClick="@(() => Pick($":{emoji.Shortcode}:"))" title="@($":{emoji.Shortcode}:")" aria-label="@($":{emoji.Shortcode}:")"
 											 data-emoji-choice="@emoji.Shortcode">
 										@* alt="": the button is named by the shortcode. *@
-										<img alt="" loading="lazy" draggable="false" class="h-6 w-6 object-contain" src="@PictureOf(emoji)" />
+										<img alt="" loading="lazy" draggable="false" class="h-6 w-6 object-contain" src="@emoji.Url" />
 									</DButton>
 								}
 							</div>
@@ -143,9 +143,6 @@
 				.Where(g => g.Emojis.Count > 0)
 		];
 
-	// the still picture when the reader asked for less motion (an animated GIF moves)
-	string PictureOf(CustomEmoji emoji) => CascadingState.Status.PrefersReducedMotion() && emoji.StaticUrl is { Length: > 0 } still ? still : emoji.Url;
-
 	async Task Opened(bool open)
 	{
 		isOpen = open;

Services/AppStatusService.cs

@@ -31,11 +31,6 @@ public class AppStatusService(IJSRuntime jsRuntime)
 		// whether the pointer can hover (a mouse); a touch screen can't, so what shows on hover there opens on a tap
 		public bool CanHover() => JsSyncRuntime.Invoke<bool>("canHover");
 
-		// read once: a card asks it for each gifv it shows
-		bool? reducedMotion;
-
-		public bool PrefersReducedMotion() => reducedMotion ??= JsSyncRuntime.Invoke<bool>("prefersReducedMotion");
-
 		// puts the text on the clipboard; false when the browser refused it, which main.js reports through logFromJs
 		public async ValueTask<bool> CopyText(string text, CancellationToken cancellationToken = default) =>
 			await jsRuntime.InvokeAsync<bool>("copyText", cancellationToken, text);

Styles/feed.css

@@ -282,12 +282,6 @@
 		stroke-dasharray: 2 6;
 	}
 
-	@media (prefers-reduced-motion: reduce) {
-		.globe-ring-value {
-			transition: none;
-		}
-	}
-
 	.globe-legend {
 		position: absolute;
 		left: 0.5rem;

decePubClient.csproj

@@ -46,9 +46,10 @@
 
   <Target Name="TailwindCompile" DependsOnTargets="EnsureTailwindTools"
           Condition="'$(DesignTimeBuild)' != 'true' And '$(NoBuild)' != 'true' And '$(SkipTailwind)' != 'true'"
-          Inputs="@(TailwindSource);$(TailwindExe);$(TailwindVendorDir)daisyui.mjs;$(TailwindVendorDir)daisyui-theme.mjs;$(MSBuildProjectFullPath)"
+          Inputs="@(TailwindSource);$(TailwindExe);$(TailwindVendorDir)daisyui.mjs;$(TailwindVendorDir)daisyui-theme.mjs;tools/css/motion.py;$(MSBuildProjectFullPath)"
           Outputs="wwwroot/css/app.css;$(IntermediateOutputPath)tailwind.stamp">
     <Exec Command="&quot;$(TailwindExe)&quot; -i Styles/app.css -o wwwroot/css/app.css $(TailwindMode)" WorkingDirectory="$(MSBuildProjectDirectory)" />
+    <Exec Command="python3 -I tools/css/motion.py wwwroot/css/app.css" WorkingDirectory="$(MSBuildProjectDirectory)" />
     <!-- The CLI leaves an unchanged output untouched, which would make this target rerun on every build. -->
     <Touch Files="wwwroot/css/app.css;$(IntermediateOutputPath)tailwind.stamp" AlwaysCreate="true" />
   </Target>

tools/css/motion.py

@@ -0,0 +1,71 @@
+import re
+import sys
+from pathlib import Path
+
+MEDIA = re.compile(r'@media([^{;]*prefers-reduced-motion[^{;]*)\{')
+MOTION = re.compile(r'\(\s*prefers-reduced-motion\s*:\s*(reduce|no-preference)\s*\)')
+
+
+def block_end(css, start):
+    depth, i, quote = 1, start, None
+    while depth:
+        ch = css[i]
+        if quote:
+            if ch == '\\':
+                i += 1
+            elif ch == quote:
+                quote = None
+        elif ch in '"\'':
+            quote = ch
+        elif ch == '{':
+            depth += 1
+        elif ch == '}':
+            depth -= 1
+        i += 1
+    return i
+
+
+def without_motion(prelude):
+    if ',' in prelude or re.search(r'\b(or|not|only)\b', prelude):
+        raise ValueError(f'@media{prelude}')
+    parts = [part.strip() for part in re.split(r'\band\b', prelude)]
+    wanted = [MOTION.fullmatch(part).group(1) for part in parts if MOTION.fullmatch(part)]
+    if len(wanted) != 1 or any('prefers-reduced-motion' in part and not MOTION.fullmatch(part) for part in parts):
+        raise ValueError(f'@media{prelude}')
+    return wanted[0], ' and '.join(part for part in parts if not MOTION.fullmatch(part))
+
+
+def everyone_moves(css):
+    out, i = [], 0
+    while match := MEDIA.search(css, i):
+        out.append(css[i:match.start()])
+        end = block_end(css, match.end())
+        wanted, rest = without_motion(match.group(1))
+        if wanted == 'no-preference':
+            inner = everyone_moves(css[match.end():end - 1])
+            if not rest and inner.strip() and not inner.rstrip().endswith((';', '}')):
+                inner += ';'
+            out.append(f'@media {rest}{{{inner}}}' if rest else inner)
+        i = end
+    out.append(css[i:])
+    return ''.join(out)
+
+
+failed = False
+for name in sys.argv[1:]:
+    path = Path(name)
+    before = path.read_text(encoding='utf-8')
+    try:
+        after = everyone_moves(before)
+    except ValueError as query:
+        print(f'{name}: cannot rewrite {query}', file=sys.stderr)
+        failed = True
+        continue
+    if 'prefers-reduced-motion' in after:
+        print(f'{name}: a prefers-reduced-motion query is still there', file=sys.stderr)
+        failed = True
+        continue
+    if after != before:
+        path.write_text(after, encoding='utf-8')
+        print(f'{name}: motion now plays for everyone')
+sys.exit(1 if failed else 0)

tools/tailwind.sh

@@ -74,7 +74,10 @@ prepare() {
 cd "$ROOT"
 case "${1:-build}" in
 	prepare) prepare ;;
-	build) prepare; "$TAILWIND" -i Styles/app.css -o wwwroot/css/app.css --optimize ;;
-	watch) prepare; exec "$TAILWIND" -i Styles/app.css -o wwwroot/css/app.css --watch ;;
+	build) prepare; "$TAILWIND" -i Styles/app.css -o wwwroot/css/app.css --optimize; python3 -I tools/css/motion.py wwwroot/css/app.css ;;
+	watch) prepare; "$TAILWIND" -i Styles/app.css -o wwwroot/css/app.css --watch 2>&1 | while IFS= read -r line; do
+		echo "$line"
+		case "$line" in Done*) python3 -I tools/css/motion.py wwwroot/css/app.css ;; esac
+	done ;;
 	*) echo "usage: tailwind.sh [prepare|build|watch]" >&2; exit 2 ;;
 esac

wwwroot/js/feed.js

@@ -46,7 +46,7 @@ export function scrollToOffset(rootId, top) {
 }
 
 export function scrollToTop(rootId) {
-	document.getElementById(rootId)?.scrollTo({ top: 0, behavior: matchMedia("(prefers-reduced-motion: reduce)").matches ? "auto" : "smooth" })
+	document.getElementById(rootId)?.scrollTo({ top: 0, behavior: "smooth" })
 }
 
 export function dispose() {

wwwroot/js/globe.js

@@ -9,7 +9,7 @@
 // night map (city lights) where it is down, blended across a twilight band, and brighter or dimmer with the Earth–Sun
 // distance. It shows now, or, while a post is hovered or focused, the moment that post was written; the Sun moves there
 // and back smoothly. Land borders are thin lines, and country names sit inside each country in the reader's language,
-// more of them and larger as the camera comes closer. Motion follows prefers-reduced-motion. It renders only while
+// more of them and larger as the camera comes closer. It renders only while
 // something moves (a camera flight, the Sun moving, a hovered post's pulse, auto-rotation, the reader dragging or
 // zooming) and never while the page or the globe is hidden: an idle globe costs no GPU time. No .NET round-trip on
 // scroll or hover: the posts' places come in one call per feed change (setPosts), the cards are matched by
@@ -21,7 +21,6 @@ import { createInstruments } from "./instruments.js"
 const vendor = new URL("../vendor/globe/", import.meta.url).href
 const textures = { day: vendor + "earth-blue-marble.jpg", night: vendor + "earth-night.jpg" }
 const countriesUrl = vendor + "countries.json"
-const reducedMotion = matchMedia("(prefers-reduced-motion: reduce)")
 // a touch screen: a tap on a card opens its thread there (main.js), so cards are pinned with a mouse only
 const canHover = matchMedia("(hover: hover)")
 
@@ -218,7 +217,7 @@ function resize() {
 		if (state.view)
 			scheduleView()
 		else
-			state.globe.pointOfView({ ...state.globe.pointOfView(), altitude: 2.6 * shape }, reducedMotion.matches ? 0 : 600)
+			state.globe.pointOfView({ ...state.globe.pointOfView(), altitude: 2.6 * shape }, 600)
 	}
 	state.shape = shape
 }
@@ -243,7 +242,7 @@ async function build(width, height) {
 			.pointRadius(p => 0.25 + Math.min(Math.sqrt(p.count), 6) * 0.12)
 			.pointColor(p => colour(p.src))
 			.pointLabel(p => label(p))
-			.pointsTransitionDuration(reducedMotion.matches ? 0 : 600)
+			.pointsTransitionDuration(600)
 			.ringColor(r => t => r.colour.replace(/[\d.]+\)$/, `${(1 - t).toFixed(2)})`))
 			.ringMaxRadius(r => r.radius)
 			.ringPropagationSpeed(r => r.speed)
@@ -254,7 +253,7 @@ async function build(width, height) {
 			.arcDashLength(0.45)
 			.arcDashGap(0.25)
 			.arcDashInitialGap(1)
-			.arcDashAnimateTime(reducedMotion.matches ? 0 : 1600)
+			.arcDashAnimateTime(1600)
 			.htmlLat(d => d.lat)
 			.htmlLng(d => d.lng)
 			.htmlAltitude(d => d.kind === "country" ? 0.004 : 0.12)
@@ -419,13 +418,10 @@ function loadNight() {
 	image.src = textures.night
 }
 
-// The Sun moves to a new moment: its subsolar point travels there over about a second (the shorter way round), or
-// jumps with reduced motion.
+// The Sun moves to a new moment: its subsolar point travels there over about a second (the shorter way round).
 function aimSun(sun) {
 	state.sun = sun
 	state.sunUniforms.sunIntensity.value = sun.irradiance
-	if (reducedMotion.matches)
-		state.sunPoint = { lat: sun.lat, lng: sun.lng }
 	state.sunUniforms.sunDirection.value = directionOf(state.sunPoint)
 	state.instruments?.setMoment(sun, state.focus)
 	state.instruments?.setSun(state.sunPoint)
@@ -659,7 +655,6 @@ function watchTheme() {
 
 function watchVisibility() {
 	listen(document, "visibilitychange", () => pause(document.visibilityState !== "visible" || !hasSize()))
-	listen(reducedMotion, "change", () => scheduleView())
 }
 
 function listen(target, type, listener) {
@@ -832,13 +827,13 @@ function drawRings() {
 	const rings = []
 	const hovered = state.hovered && state.points.get(state.hovered)
 	if (placed(hovered))
-		rings.push({ lat: hovered.lat, lng: hovered.lng, radius: 4, speed: 3, period: reducedMotion.matches ? 100000 : 900, colour: colour(hovered.src, 1) })
+		rings.push({ lat: hovered.lat, lng: hovered.lng, radius: 4, speed: 3, period: 900, colour: colour(hovered.src, 1) })
 	else if (hovered && Number.isFinite(hovered.beforeLat))
-		rings.push({ lat: hovered.beforeLat, lng: hovered.beforeLng, radius: 3, speed: 1.5, period: reducedMotion.matches ? 100000 : 1400, colour: colour("country", 1) })
+		rings.push({ lat: hovered.beforeLat, lng: hovered.beforeLng, radius: 3, speed: 1.5, period: 1400, colour: colour("country", 1) })
 	const reach = Math.max(0, ...[...state.points.values()].filter(p => p.src === "nearyou").map(p => p.range ?? 0))
 	const reader = [...state.points.values()].find(p => p.src === "nearyou")
 	if (reader && reach > 0)
-		rings.push({ lat: reader.lat, lng: reader.lng, radius: reach / 111, speed: reach / 111 / 2, period: reducedMotion.matches ? 100000 : 2400, colour: colour("nearyou", 0.8) })
+		rings.push({ lat: reader.lat, lng: reader.lng, radius: reach / 111, speed: reach / 111 / 2, period: 2400, colour: colour("nearyou", 0.8) })
 	state.globe.ringsData(rings)
 }
 
@@ -894,7 +889,7 @@ function updateView() {
 		state.view = null
 		state.spreadKm = 0
 		state.instruments?.setView(null, 0, [], { located: 0, visible: state.visible.size })
-		controls.autoRotate = !reducedMotion.matches
+		controls.autoRotate = true
 		wake()
 		return
 	}
@@ -921,8 +916,8 @@ function updateView() {
 function fly(view, ms) {
 	if (!view || !state?.globe)
 		return
-	wake((reducedMotion.matches ? 0 : ms) + 400)
-	state.globe.pointOfView(view, reducedMotion.matches ? 0 : ms)
+	wake(ms + 400)
+	state.globe.pointOfView(view, ms)
 }
 
 // A column taller than wide shows less of the globe across: the camera moves back to keep it whole.

wwwroot/main.js

@@ -108,6 +108,10 @@ document.addEventListener("click", event => {
 		window.logFromJs(e.message, "openThread")
 	}
 })
+document.addEventListener("loadstart", event => {
+	if (event.target instanceof HTMLVideoElement && event.target.hasAttribute("muted"))
+		event.target.muted = true
+}, { capture: true })
 // The Back button (a popstate) as opposed to the app's own navigation: Blazor's location-changing handlers can't tell
 // them apart, and MainLayout lets Back close an open overlay but lets the app's navigation through. Registered for the
 // capture phase, so it runs before Blazor's own listener.
@@ -136,16 +140,6 @@ window.revealActive = strip => {
 		window.logFromJs(e.message, "revealActive")
 	}
 }
-// the reader asked for less motion: what would move by itself (a gifv) waits for a tap
-window.prefersReducedMotion = () => {
-	try {
-		return window.matchMedia("(prefers-reduced-motion: reduce)").matches
-	} catch (e) {
-		console.error(e)
-		window.logFromJs(e.message, "prefersReducedMotion")
-		return false
-	}
-}
 // text put on the clipboard (the recovery codes of two-factor sign-in); false when the browser refused it
 window.copyText = async text => {
 	try {