fix(#103): move language switcher from header into mobile nav drawer

On mobile the header is now cleaner — language buttons move to the
bottom of the hamburger panel. Desktop header is unchanged (sm:flex).

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

frontend/src/lib/components/DocumentBottomPanel.svelte

@@ -107,7 +107,7 @@ function handleCountChange(count: number) {
 </script>
 
 <div
-	class="fixed right-0 bottom-0 left-0 z-30 flex flex-col border-t border-line bg-surface shadow-[0_-4px_16px_rgba(0,0,0,0.08)]"
+	class="z-30 flex shrink-0 flex-col border-t border-line bg-surface shadow-[0_-4px_16px_rgba(0,0,0,0.08)]"
 	style="height: {panelHeight}px"
 	data-testid="bottom-panel"
 >
@@ -127,35 +127,37 @@ function handleCountChange(count: number) {
 	</div>
 
 	<!-- Tab bar -->
-	<div class="flex shrink-0 items-center border-b border-line bg-surface px-4">
-		{#each tabs as tab (tab.id)}
-			<button
-				onclick={() => openTab(tab.id)}
-				class="mr-1 px-3 py-2.5 font-sans text-xs font-medium transition-colors {activeTab === tab.id && open
-					? 'border-b-2 border-primary text-ink'
-					: 'text-ink-3 hover:text-ink'}"
-				aria-pressed={activeTab === tab.id && open}
-			>
-				{tab.label()}
-				{#if tab.id === 'discussion'}
-					<span
-						data-testid="discussion-count-badge"
-						class="ml-1.5 inline-flex h-4 min-w-4 items-center justify-center rounded-full bg-primary px-1 font-sans text-[10px] font-bold text-primary-fg"
-						>{discussionCount}</span
-					>
-				{/if}
-			</button>
-		{/each}
-
-		<!-- spacer -->
-		<div class="flex-1"></div>
+	<div class="flex shrink-0 items-center border-b border-line bg-surface">
+		<!-- Scrollable tabs area — hides scrollbar visually -->
+		<div
+			class="flex flex-1 items-center overflow-x-auto px-2 [scrollbar-width:none] [&::-webkit-scrollbar]:hidden"
+		>
+			{#each tabs as tab (tab.id)}
+				<button
+					onclick={() => openTab(tab.id)}
+					class="mr-1 shrink-0 px-3 py-2.5 font-sans text-xs font-medium transition-colors {activeTab === tab.id && open
+						? 'border-b-2 border-primary text-ink'
+						: 'text-ink-3 hover:text-ink'}"
+					aria-pressed={activeTab === tab.id && open}
+				>
+					{tab.label()}
+					{#if tab.id === 'discussion'}
+						<span
+							data-testid="discussion-count-badge"
+							class="ml-1.5 inline-flex h-4 min-w-4 items-center justify-center rounded-full bg-primary px-1 font-sans text-[10px] font-bold text-primary-fg"
+							>{discussionCount}</span
+						>
+					{/if}
+				</button>
+			{/each}
+		</div>
 
 		{#if open}
 			<button
 				onclick={closePanel}
 				data-testid="panel-close-btn"
 				aria-label="Panel schließen"
-				class="rounded p-1.5 text-ink-3 transition-colors hover:bg-muted hover:text-ink"
+				class="mr-2 shrink-0 rounded p-1.5 text-ink-3 transition-colors hover:bg-muted hover:text-ink"
 			>
 				<svg class="h-4 w-4" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2">
 					<path stroke-linecap="round" stroke-linejoin="round" d="M6 18L18 6M6 6l12 12" />

frontend/src/lib/components/DocumentTopBar.svelte

@@ -58,7 +58,7 @@ const compactMeta = $derived.by(() => {
 </script>
 
 <div
-	class="z-20 flex shrink-0 items-center justify-between border-b border-line bg-surface px-6 py-3 shadow-sm"
+	class="z-20 flex shrink-0 items-center justify-between border-b border-line bg-surface px-3 py-3 shadow-sm sm:px-6"
 	data-topbar
 >
 	<!-- Left: back + title -->
@@ -111,13 +111,16 @@ const compactMeta = $derived.by(() => {
 					aria-hidden="true"
 					class="h-4 w-4 {annotateMode ? 'invert' : ''}"
 				/>
-				{annotateMode ? m.doc_panel_annotate_stop() : m.doc_panel_annotate()}
+				<span class="hidden sm:inline"
+					>{annotateMode ? m.doc_panel_annotate_stop() : m.doc_panel_annotate()}</span
+				>
 			</button>
 		{/if}
 
 		{#if canWrite}
 			<a
 				href="/documents/{doc.id}/edit"
+				aria-label={m.btn_edit()}
 				class="flex items-center gap-2 rounded border border-primary bg-transparent px-3 py-1.5 text-xs font-medium text-ink transition hover:bg-primary hover:text-primary-fg"
 			>
 				<img
@@ -126,7 +129,7 @@ const compactMeta = $derived.by(() => {
 					aria-hidden="true"
 					class="h-4 w-4"
 				/>
-				{m.btn_edit()}
+				<span class="hidden sm:inline">{m.btn_edit()}</span>
 			</a>
 		{/if}
 

frontend/src/routes/+layout.svelte

@@ -46,8 +46,8 @@ const userInitials = $derived.by(() => {
 
 					<!-- Right Side -->
 					<div class="flex items-center gap-3">
-						<!-- Language selector -->
-						<div class="flex items-center gap-1 border-r border-line pr-3">
+						<!-- Language selector (desktop only — mobile lives in nav drawer) -->
+						<div class="hidden items-center gap-1 border-r border-line pr-3 sm:flex">
 							{#each locales as locale (locale)}
 								<button
 									type="button"

frontend/src/routes/AppNav.svelte

@@ -2,9 +2,14 @@
 import { page } from '$app/state';
 import { untrack } from 'svelte';
 import { m } from '$lib/paraglide/messages.js';
+import { setLocale, getLocale } from '$lib/paraglide/runtime';
 
 let { isAdmin = false }: { isAdmin?: boolean } = $props();
 
+const locales = ['DE', 'EN', 'ES'] as const;
+const localeMap = { DE: 'de', EN: 'en', ES: 'es' } as const;
+const activeLocale = $derived(getLocale().toUpperCase());
+
 let mobileNavOpen = $state(false);
 
 $effect(() => {
@@ -180,6 +185,22 @@ function handleOverlayKeydown(event: KeyboardEvent) {
 						{m.nav_admin()}
 					</a>
 				{/if}
+
+				<!-- Language switcher -->
+				<div class="flex items-center gap-2 border-t border-line px-4 py-3">
+					{#each locales as locale (locale)}
+						<button
+							type="button"
+							onclick={() => setLocale(localeMap[locale])}
+							class="min-h-[44px] px-3 font-sans text-sm tracking-widest transition-colors
+                               {activeLocale === locale
+                                ? 'font-bold text-ink'
+                                : 'font-normal text-ink-3 hover:text-ink'}"
+						>
+							{locale}
+						</button>
+					{/each}
+				</div>
 			</nav>
 		</div>
 	</div>

frontend/src/routes/DropZone.svelte

@@ -146,7 +146,7 @@ $effect(() => {
 		? 'border-primary bg-accent-bg py-10 text-primary'
 		: windowDragging
 			? 'border-primary/60 bg-accent-bg/50 py-10 text-primary/80'
-			: 'border-ink/20 py-6 text-ink-3 hover:border-primary hover:text-primary'}"
+			: 'border-ink/30 py-6 text-ink-3 hover:border-primary hover:text-primary'}"
 	ondragover={handleDragOver}
 	ondragleave={handleDragLeave}
 	ondrop={handleDrop}

frontend/src/routes/documents/[id]/edit/FileSectionEdit.svelte

@@ -2,14 +2,24 @@
 import { m } from '$lib/paraglide/messages.js';
 
 let { originalFilename }: { originalFilename: string } = $props();
+
+let selectedFilename = $state<string | null>(null);
+
+function handleFileChange(e: Event) {
+	const file = (e.target as HTMLInputElement).files?.[0];
+	selectedFilename = file?.name ?? null;
+}
 </script>
 
-<div class="rounded-sm border border-line bg-surface p-6 shadow-sm">
-	<h2 class="mb-5 text-xs font-bold tracking-widest text-ink-3 uppercase">
-		{m.doc_section_file()}
-	</h2>
+<div class="rounded-sm border border-line bg-surface shadow-sm">
+	<div class="border-b border-line px-6 py-4">
+		<h2 class="text-xs font-bold tracking-widest text-ink-3 uppercase">
+			{m.doc_section_file()}
+		</h2>
+	</div>
 
-	<div class="mb-4 flex items-center gap-3 rounded bg-muted px-3 py-2 text-sm text-ink-2">
+	<!-- Current file -->
+	<div class="flex items-center gap-3 border-b border-line px-6 py-3 text-sm text-ink-2">
 		<img
 			src="/degruyter-icons/Simple/Medium-24px/SVG/Action/PDF-Document-MD.svg"
 			alt=""
@@ -22,19 +32,31 @@ let { originalFilename }: { originalFilename: string } = $props();
 		>
 	</div>
 
-	<label for="file-upload" class="mb-1 block text-sm font-medium text-ink-2">
-		{m.doc_file_replace_label()}
-		<span class="font-normal text-ink-3">({m.doc_file_replace_note()})</span>
+	<!-- Replace file upload zone -->
+	<label
+		for="file-upload"
+		class="flex cursor-pointer flex-col items-center gap-3 px-6 py-8 transition-colors hover:bg-muted/40"
+	>
+		<svg
+			class="h-8 w-8 text-ink-3"
+			fill="none"
+			stroke="currentColor"
+			viewBox="0 0 24 24"
+			aria-hidden="true"
+		>
+			<path
+				stroke-linecap="round"
+				stroke-linejoin="round"
+				stroke-width="1.5"
+				d="M4 16v1a3 3 0 003 3h10a3 3 0 003-3v-1m-4-8l-4-4m0 0L8 8m4-4v12"
+			/>
+		</svg>
+		{#if selectedFilename}
+			<span class="text-sm font-medium text-ink">{selectedFilename}</span>
+		{:else}
+			<span class="text-sm font-medium text-ink-2">{m.doc_file_replace_label()}</span>
+			<span class="text-xs text-ink-3">{m.doc_file_replace_note()}</span>
+		{/if}
 	</label>
-	<input
-		id="file-upload"
-		type="file"
-		name="file"
-		class="block w-full cursor-pointer text-sm
-               text-ink-2 file:mr-4 file:rounded
-               file:border-0 file:bg-muted
-               file:px-4 file:py-2
-               file:text-sm file:font-semibold
-               file:text-ink hover:file:bg-muted"
-	/>
+	<input id="file-upload" type="file" name="file" onchange={handleFileChange} class="sr-only" />
 </div>

frontend/src/routes/layout.css

@@ -96,8 +96,8 @@
 		--c-overlay: #242424;
 		--c-muted: #252525;
 
-		--c-line: #2e2e2e;
-		--c-line-2: #222222;
+		--c-line: #3d3d3d;
+		--c-line-2: #2e2e2e;
 
 		--c-ink: #f0efe9;
 		--c-ink-2: #9ca3af; /* gray-400 — 7.5:1 on dark surface — WCAG AAA ✓ */
@@ -124,8 +124,8 @@
 	--c-overlay: #242424;
 	--c-muted: #252525;
 
-	--c-line: #2e2e2e;
-	--c-line-2: #222222;
+	--c-line: #3d3d3d;
+	--c-line-2: #2e2e2e;
 
 	--c-ink: #f0efe9;
 	--c-ink-2: #9ca3af;

frontend/src/routes/persons/+page.svelte

@@ -23,7 +23,7 @@ function handleSearch() {
 }
 </script>
 
-<div class="mx-auto max-w-7xl py-12 sm:px-6 lg:px-8">
+<div class="mx-auto max-w-7xl px-4 py-12 sm:px-6 lg:px-8">
 	<!-- Header Area -->
 	<div
 		class="mb-10 flex flex-col justify-between gap-6 border-b border-ink/10 pb-6 md:flex-row md:items-end"