fix(ui): semantic turquoise tokens, badge styling, saved fade animation

- Add turquoise/turquoise-fg semantic color tokens to layout.css
  (light + dark mode), replacing all hardcoded #00C7B1 in components
- Bump Details toggle from text-xs to text-sm for visual hierarchy
- Block badge: navy → turquoise, overlapping top-left card border
  with absolute positioning to visually link PDF annotation badges
- Saved indicator: smooth 300ms opacity fade before removal
  (new 'fading' state in SaveState type)
- Transcribe buttons: use border-turquoise/bg-turquoise/text-turquoise-fg

Fixes @Leonie concerns: toggle visual weight, semantic tokens,
badge styling, saved fade animation

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

frontend/src/lib/components/DocumentTopBar.svelte

@@ -111,7 +111,7 @@ let mobileMenuOpen = $state(false);
 		aria-pressed={false}
 		class={mobile
 			? 'flex w-full items-center gap-2 rounded px-3 py-2 text-left text-[16px] text-ink transition hover:bg-muted focus-visible:ring-2 focus-visible:ring-primary'
-			: 'hidden items-center gap-1.5 rounded border border-[#00C7B1] px-3 py-1.5 font-sans text-[16px] font-medium text-ink transition hover:bg-[#00C7B1] hover:text-white focus-visible:ring-2 focus-visible:ring-primary md:flex'}
+			: 'hidden items-center gap-1.5 rounded border border-turquoise px-3 py-1.5 font-sans text-[16px] font-medium text-ink transition hover:bg-turquoise hover:text-turquoise-fg focus-visible:ring-2 focus-visible:ring-primary md:flex'}
 	>
 		<svg
 			class="h-5 w-5 shrink-0"
@@ -139,8 +139,8 @@ let mobileMenuOpen = $state(false);
 		aria-label={m.transcription_mode_stop()}
 		aria-pressed={true}
 		class={mobile
-			? 'flex w-full items-center gap-2 rounded bg-[#00C7B1] px-3 py-2 text-left text-[16px] text-white transition focus-visible:ring-2 focus-visible:ring-primary'
+			? 'flex w-full items-center gap-2 rounded bg-turquoise px-3 py-2 text-left text-[16px] text-turquoise-fg transition focus-visible:ring-2 focus-visible:ring-primary'
-			: 'flex items-center gap-1.5 rounded bg-[#00C7B1] px-3 py-1.5 font-sans text-[16px] font-medium text-white transition focus-visible:ring-2 focus-visible:ring-primary'}
+			: 'flex items-center gap-1.5 rounded bg-turquoise px-3 py-1.5 font-sans text-[16px] font-medium text-white transition focus-visible:ring-2 focus-visible:ring-primary'}
 	>
 		<svg
 			class="h-5 w-5 shrink-0"
@@ -236,7 +236,7 @@ let mobileMenuOpen = $state(false);
 			onclick={() => (detailsOpen = !detailsOpen)}
 			aria-expanded={detailsOpen}
 			aria-label={m.doc_details_toggle()}
-			class="ml-2 inline-flex min-h-[44px] shrink-0 items-center gap-1 rounded border px-2 py-1 font-sans text-xs font-semibold transition-colors {detailsOpen ? 'border-primary bg-primary text-primary-fg' : 'border-line text-ink-2 hover:bg-muted hover:text-ink'}"
+			class="ml-2 inline-flex min-h-[44px] shrink-0 items-center gap-1.5 rounded border px-3 py-1 font-sans text-sm font-semibold transition-colors {detailsOpen ? 'border-primary bg-primary text-primary-fg' : 'border-line text-ink-2 hover:bg-muted hover:text-ink'}"
 		>
 			{m.doc_details_toggle()}
 			<svg

frontend/src/lib/components/TranscriptionBlock.svelte

@@ -1,7 +1,7 @@
 <script lang="ts">
 import { m } from '$lib/paraglide/messages.js';
 
-type SaveState = 'idle' | 'saving' | 'saved' | 'error';
+type SaveState = 'idle' | 'saving' | 'saved' | 'fading' | 'error';
 
 type Props = {
 	blockId: string;
@@ -30,7 +30,7 @@ let {
 }: Props = $props();
 
 let leftBorderClass = $derived(
-	saveState === 'error' ? 'border-l-2 border-error' : active ? 'border-l-2 border-[#00C7B1]' : ''
+	saveState === 'error' ? 'border-l-2 border-error' : active ? 'border-l-2 border-turquoise' : ''
 );
 
 function autoresize(node: HTMLTextAreaElement) {
@@ -61,15 +61,19 @@ function handleDelete() {
 }
 </script>
 
-<div class="overflow-hidden rounded border border-line {leftBorderClass}" data-block-id={blockId}>
+<div
-	<div class="p-4">
+	class="relative overflow-visible rounded border border-line {leftBorderClass}"
+	data-block-id={blockId}
+>
+	<!-- Turquoise numbered badge — overlaps top-left of card -->
+	<span
+		class="absolute -top-2 -left-2 z-10 flex h-6 w-6 items-center justify-center rounded-full bg-turquoise text-xs font-bold text-turquoise-fg shadow-sm"
+	>
+		{blockNumber}
+	</span>
+	<div class="p-4 pl-6">
 		<!-- Header -->
 		<div class="mb-2 flex items-center gap-2">
-			<span
-				class="flex h-6 w-6 items-center justify-center rounded-full bg-[#002850] text-xs font-bold text-white"
-			>
-				{blockNumber}
-			</span>
 			{#if label}
 				<span class="text-xs font-medium tracking-wide text-ink-2 uppercase">
 					{label}
@@ -96,8 +100,10 @@ function handleDelete() {
 					<span class="animate-pulse text-xs text-ink-3">
 						{m.transcription_block_save_saving()}
 					</span>
-				{:else if saveState === 'saved'}
+				{:else if saveState === 'saved' || saveState === 'fading'}
-					<span class="text-xs text-green-600">
+					<span
+						class="text-xs text-green-600 transition-opacity duration-300 {saveState === 'fading' ? 'opacity-0' : 'opacity-100'}"
+					>
 						{m.transcription_block_save_saved()} <span class="inline-block">&#10003;</span>
 					</span>
 				{:else if saveState === 'error'}

frontend/src/lib/components/TranscriptionEditView.svelte

@@ -4,7 +4,7 @@ import { SvelteMap } from 'svelte/reactivity';
 import TranscriptionBlock from './TranscriptionBlock.svelte';
 import type { TranscriptionBlockData } from '$lib/types';
 
-type SaveState = 'idle' | 'saving' | 'saved' | 'error';
+type SaveState = 'idle' | 'saving' | 'saved' | 'fading' | 'error';
 
 type Props = {
 	blocks: TranscriptionBlockData[];
@@ -50,7 +50,12 @@ async function executeSave(blockId: string) {
 function scheduleSavedFade(blockId: string) {
 	setTimeout(() => {
 		if (getSaveState(blockId) === 'saved') {
-			setSaveState(blockId, 'idle');
+			setSaveState(blockId, 'fading');
+			setTimeout(() => {
+				if (getSaveState(blockId) === 'fading') {
+					setSaveState(blockId, 'idle');
+				}
+			}, 300);
 		}
 	}, 2000);
 }

frontend/src/routes/layout.css

@@ -59,6 +59,10 @@
 	/* Header surface — independent from canvas/surface for per-mode control */
 	--color-header: var(--c-header);
 
+	/* Turquoise — transcription mode accent */
+	--color-turquoise: var(--c-turquoise);
+	--color-turquoise-fg: var(--c-turquoise-fg);
+
 	/* Focus ring — keyboard focus indicator, mode-aware (navy in light, mint in dark) */
 	--color-focus-ring: var(--c-focus-ring);
 
@@ -93,6 +97,9 @@
 	/* Header is brand-navy in light mode; same in dark mode for contrast compliance */
 	--c-header: #012851;
 
+	--c-turquoise: #00c7b1;
+	--c-turquoise-fg: #ffffff;
+
 	/* Focus ring: brand-navy in light mode — 14:1 on white, ~11:1 on sand */
 	--c-focus-ring: #012851;
 
@@ -132,6 +139,9 @@
 		/* Header at brand-navy: 4.99:1 with ink-3 (WCAG AA ✓), visually above canvas */
 		--c-header: #012851;
 
+		--c-turquoise: #00c7b1;
+		--c-turquoise-fg: #012851;
+
 		/* Focus ring: brand-mint in dark mode — 9.2:1 on canvas, 7.1:1 on surface */
 		--c-focus-ring: #a1dcd8;
 
@@ -167,6 +177,9 @@
 	/* Header at brand-navy: 4.99:1 with ink-3 (WCAG AA ✓), visually above canvas */
 	--c-header: #012851;
 
+	--c-turquoise: #00c7b1;
+	--c-turquoise-fg: #012851;
+
 	/* Focus ring: brand-mint in dark mode — 9.2:1 on canvas, 7.1:1 on surface */
 	--c-focus-ring: #a1dcd8;