Refine themes, add sidebar controls, and theme docs

Refined: softer dark-mode link color (#a0c4e8), fix export button
vertical alignment with inline-flex, tighten settings page spacing
(reduce gaps from 3rem to 1.5rem).

Terminal: switch accent from cyan to green (#4ae54a dark / #1a7a2e
light), add proper light mode with pale steel background, scanlines
only in dark mode.

Sidebar: add quick-access controls in footer — moon/sun icon toggles
light/dark, circle icon cycles through style themes showing current
name. Both update reactively on state change.

Add THEMES.md with full documentation on creating new themes:
variable reference, selector guide, light/dark mode tips, and the
registration process.

https://claude.ai/code/session_01Jv3c8GdaDQMm5WYwHUJMVe

5 files changed, 342 insertions, 80 deletions

diff --git a/frontend-vanilla/THEMES.md b/frontend-vanilla/THEMES.md
new file mode 100644
index 0000000..8367046
--- /dev/null
+++ b/frontend-vanilla/THEMES.md
@@ -0,0 +1,151 @@
+# Creating a New Theme
+
+Neko's style theme system layers an additional CSS file on top of the base
+stylesheet. The base `style.css` defines CSS custom properties (variables) and
+all component styles. A theme file overrides whichever of those it wants.
+
+## Quick Start
+
+1. Create a new CSS file in `frontend-vanilla/public/themes/yourtheme.css`
+2. Register the theme name in `frontend-vanilla/src/main.ts` — add it to the
+   `STYLE_THEMES` array:
+   ```ts
+   const STYLE_THEMES = ['default', 'refined', 'terminal', 'codex', 'sakura', 'yourtheme'] as const;
+   ```
+3. Rebuild: `cd frontend-vanilla && npm run build`
+4. Copy output: `cp -r dist/* ../web/dist/v3/`
+
+That's it. The theme will appear in Settings > Style and in the sidebar cycle
+button.
+
+## How it works
+
+When a user picks a style theme, JavaScript inserts a `<link>` tag:
+
+```html
+<link id="style-theme-link" rel="stylesheet" href="/v3/themes/yourtheme.css">
+```
+
+This loads *after* the base stylesheet, so any rules you write will override
+the defaults via normal CSS cascade (same specificity = last one wins). When
+the user switches to "Default," the link tag is removed entirely.
+
+The theme CSS files live in `public/themes/` so Vite copies them as-is into the
+build output (no hashing, no bundling). They're plain CSS — no build step
+required for the theme file itself.
+
+## CSS Variables You Can Override
+
+The base stylesheet defines these custom properties on `:root` (light mode)
+and `.theme-dark` (dark mode):
+
+```css
+/* Colors */
+--bg-color          /* Page background */
+--text-color        /* Primary text */
+--sidebar-bg        /* Sidebar background */
+--link-color        /* Links and titles */
+--border-color      /* Borders, rules, dividers */
+--accent-color      /* Interactive accent (selection, focus) */
+
+/* Fonts */
+--font-body         /* Body/article text (default: Palatino stack) */
+--font-heading      /* Dynamic heading font (user-selectable) */
+--font-heading-system  /* System heading font (Helvetica Neue stack) */
+--font-sans         /* Sans-serif stack (Inter/system-ui) */
+--font-mono         /* Monospace stack (Courier New) */
+```
+
+### Supporting both light and dark mode
+
+Your theme should define colors for both modes:
+
+```css
+/* Light mode */
+:root {
+  --bg-color: #faf8f4;
+  --text-color: #2c2c2c;
+  --link-color: #8b4513;
+  /* ... */
+}
+
+/* Dark mode */
+.theme-dark {
+  --bg-color: #1c1a17;
+  --text-color: #d4cfc6;
+  --link-color: #c9956b;
+  /* ... */
+}
+```
+
+The light/dark toggle adds/removes the `theme-dark` class on `#app`. Your
+theme's `.theme-dark` rules will override your `:root` rules when active.
+
+**Important:** The base stylesheet has some `.theme-dark .sidebar` rules that
+set the sidebar to a grey background with dark text. If your theme wants a
+different dark-mode sidebar, you'll need to override those specifically:
+
+```css
+.theme-dark .sidebar { background: ...; }
+.theme-dark .sidebar-section li a { color: ...; }
+.theme-dark .sidebar-section h3 { color: ...; }
+.theme-dark .sidebar-footer a { color: ...; }
+```
+
+## Key Selectors Reference
+
+### Layout
+- `.sidebar` — Fixed sidebar (11rem wide)
+- `.main-content` — Scrollable content area
+- `.main-content > *` — Content max-width container (default: 35em)
+
+### Feed items
+- `.feed-item` — Individual article wrapper
+- `.item-title` — Article title/link
+- `.dateline` — Date + feed source line
+- `.item-description` — Article body content
+- `.star-btn` / `.star-btn.is-starred` / `.star-btn.is-unstarred` — Star toggle
+- `.scrape-btn` — "text" button for full-content fetch
+
+### Settings page
+- `.settings-view` — Settings container
+- `.settings-section` / `.settings-section h3` — Section blocks
+- `.settings-group` / `.data-group` — Form groups
+- `.theme-options` — Button row for theme/style selectors
+- `.button-group` — Button row for export/import
+- `.manage-feed-list` / `.manage-feed-item` — Feed management list
+
+### Buttons
+- `button` / `.button` — All buttons and button-styled links
+- `button.active` — Currently selected option
+
+### Sidebar details
+- `.sidebar-section h3` — Section headers (FEEDS, TAGS)
+- `.sidebar-section li a` — Feed/filter links
+- `.sidebar-section li.active a` — Selected item
+- `.sidebar-footer` — Bottom area (settings, logout, controls)
+- `.sidebar-quick-controls` / `.sidebar-icon-btn` — Theme toggle icons
+
+## Tips
+
+- **Override fonts broadly.** Set `font-family` on `body` for article text and
+  on `.sidebar`, `.settings-view`, `button` for UI elements.
+- **Use the cascade.** You don't need `!important` — your theme loads after the
+  base stylesheet. Just match or exceed the specificity of the base rule.
+- **Keep it to overrides.** Don't redefine layout or structural properties
+  unless you have a reason. Focus on colors, typography, and spacing.
+- **Test both modes.** Always check your theme in both light and dark.
+- **Note on font overrides:** The user can independently select heading and body
+  fonts in Settings > Fonts. These apply CSS classes like `.font-sans`,
+  `.heading-font-serif`, etc. Your theme's font choices will be the "default"
+  that users see before changing font settings.
+
+## Existing Themes
+
+| Theme      | Character |
+|------------|-----------|
+| `default`  | No extra CSS — the base stylesheet as-is |
+| `refined`  | Tightened spacing, better typographic rhythm, polished details |
+| `terminal` | Monospace, green phosphor accent, CRT scanlines in dark mode |
+| `codex`    | Book-inspired: warm cream paper, serif type, fleuron separators |
+| `sakura`   | Japanese aesthetic: restrained palette, muted rose accent, calm spacing |
diff --git a/frontend-vanilla/public/themes/refined.css b/frontend-vanilla/public/themes/refined.css
index 9143552..fab2b96 100644
--- a/frontend-vanilla/public/themes/refined.css
+++ b/frontend-vanilla/public/themes/refined.css
@@ -14,7 +14,12 @@
   --spacing-md: 1rem;
   --spacing-lg: 1.5rem;
   --spacing-xl: 2rem;
-  --spacing-2xl: 3rem;
+}
+
+/* Dark mode: a warmer, softer link color */
+.theme-dark {
+  --link-color: #a0c4e8;
+  --accent-color: #6fa8d6;
 }
 
 /* Slightly refined base typography */
@@ -114,22 +119,21 @@ body {
 }
 
 /* ---- Settings Page Refinements ---- */
-/* This is where the biggest improvements are needed */
 
 .settings-view {
-  padding-top: var(--spacing-xl);
+  padding-top: var(--spacing-lg);
 }
 
 .settings-view h2 {
   font-size: 1.8rem;
   font-weight: 700;
-  margin-bottom: var(--spacing-2xl);
+  margin-bottom: var(--spacing-xl);
   letter-spacing: -0.025em;
 }
 
 .settings-grid {
-  gap: var(--spacing-2xl);
-  margin-bottom: var(--spacing-2xl);
+  gap: var(--spacing-lg);
+  margin-bottom: var(--spacing-lg);
 }
 
 .settings-section {
@@ -140,28 +144,28 @@ body {
 .settings-section h3 {
   font-size: 1.1rem;
   font-weight: 700;
-  margin-bottom: var(--spacing-lg);
-  padding-bottom: var(--spacing-sm);
+  margin-bottom: var(--spacing-sm);
+  padding-bottom: var(--spacing-xs);
   border-bottom: 1px solid var(--border-color);
 }
 
 .settings-group,
 .data-group {
-  margin-bottom: var(--spacing-lg);
+  margin-bottom: var(--spacing-sm);
 }
 
 .settings-group label,
 .data-group label {
   font-size: 0.75rem;
   letter-spacing: 0.1em;
-  margin-bottom: var(--spacing-sm);
+  margin-bottom: var(--spacing-xs);
 }
 
 .theme-options {
   gap: var(--spacing-sm);
 }
 
-/* Consistent button sizing */
+/* Consistent button sizing & vertical centering fix */
 button,
 .button {
   height: 2.2rem;
@@ -169,12 +173,15 @@ button,
   font-size: 0.75rem;
   letter-spacing: 0.06em;
   border-radius: 5px;
+  display: inline-flex;
+  align-items: center;
+  justify-content: center;
 }
 
 /* Add feed form alignment */
 .add-feed-form {
   gap: var(--spacing-sm);
-  margin-bottom: var(--spacing-xl);
+  margin-bottom: var(--spacing-lg);
 }
 
 .add-feed-form input {
@@ -183,7 +190,7 @@ button,
 
 /* Manage feeds list consistency */
 .manage-feeds-section {
-  margin-top: var(--spacing-2xl);
+  margin-top: var(--spacing-xl);
 }
 
 .manage-feed-item {
diff --git a/frontend-vanilla/public/themes/terminal.css b/frontend-vanilla/public/themes/terminal.css
index f497dfa..dd9c1b2 100644
--- a/frontend-vanilla/public/themes/terminal.css
+++ b/frontend-vanilla/public/themes/terminal.css
@@ -6,32 +6,38 @@
  */
 
 /* ---- Color System ---- */
+/* Light mode: bright terminal on a pale steel background */
 :root {
-  --bg-color: #0a0e14;
-  --text-color: #b0bec5;
-  --sidebar-bg: #0d1117;
-  --link-color: #00e5ff;
-  --border-color: #1e2a35;
-  --accent-color: #00e5ff;
-
-  --terminal-glow: rgba(0, 229, 255, 0.08);
-  --terminal-dim: rgba(0, 229, 255, 0.03);
-  --terminal-green: #39ff14;
-  --terminal-cyan: #00e5ff;
-  --terminal-magenta: #ff00ff;
-  --terminal-amber: #ffab00;
+  --bg-color: #f0f2f0;
+  --text-color: #1e2d1e;
+  --sidebar-bg: #e4e8e4;
+  --link-color: #1a7a2e;
+  --border-color: #c4cec4;
+  --accent-color: #1a7a2e;
+
+  --terminal-accent: #1a7a2e;
+  --terminal-glow: rgba(26, 122, 46, 0.08);
+  --terminal-dim: rgba(26, 122, 46, 0.03);
+  --terminal-amber: #a66800;
+  --terminal-red: #c62828;
 
-  color-scheme: dark;
+  color-scheme: light dark;
 }
 
-/* Override dark theme if also applied */
+/* Dark mode: phosphor green on black */
 .theme-dark {
-  --bg-color: #0a0e14;
-  --text-color: #b0bec5;
-  --sidebar-bg: #0d1117;
-  --link-color: #00e5ff;
-  --border-color: #1e2a35;
-  --accent-color: #00e5ff;
+  --bg-color: #0a0e0a;
+  --text-color: #b0bfb0;
+  --sidebar-bg: #0d110d;
+  --link-color: #4ae54a;
+  --border-color: #1e2a1e;
+  --accent-color: #4ae54a;
+
+  --terminal-accent: #4ae54a;
+  --terminal-glow: rgba(74, 229, 74, 0.08);
+  --terminal-dim: rgba(74, 229, 74, 0.03);
+  --terminal-amber: #ffab00;
+  --terminal-red: #ff5252;
 }
 
 /* ---- Typography ---- */
@@ -46,8 +52,8 @@ body {
   -webkit-font-smoothing: antialiased;
 }
 
-/* Subtle scanline overlay on the whole page */
-body::after {
+/* Subtle scanline overlay -- only in dark mode */
+.theme-dark body::after {
   content: '';
   position: fixed;
   top: 0;
@@ -82,14 +88,14 @@ body::after {
 
 .sidebar-section h3 {
   font-family: inherit;
-  color: var(--terminal-cyan);
+  color: var(--terminal-accent);
   opacity: 0.6;
   font-size: 0.65rem;
   letter-spacing: 0.2em;
 }
 
 .theme-dark .sidebar-section h3 {
-  color: var(--terminal-cyan);
+  color: var(--terminal-accent);
 }
 
 .sidebar-section li a {
@@ -105,19 +111,19 @@ body::after {
 
 .sidebar-section li a:hover {
   background: var(--terminal-glow);
-  color: var(--terminal-cyan);
+  color: var(--terminal-accent);
   transform: none;
 }
 
 .theme-dark .sidebar-section li a:hover {
   background: var(--terminal-glow);
-  color: var(--terminal-cyan);
+  color: var(--terminal-accent);
 }
 
 .sidebar-section li.active a {
   background: var(--terminal-glow);
-  color: var(--terminal-cyan);
-  box-shadow: inset 2px 0 0 var(--terminal-cyan);
+  color: var(--terminal-accent);
+  box-shadow: inset 2px 0 0 var(--terminal-accent);
   border: none;
   border-radius: 0;
   font-weight: 500;
@@ -125,7 +131,7 @@ body::after {
 
 .theme-dark .sidebar-section li.active a {
   background: var(--terminal-glow);
-  color: var(--terminal-cyan);
+  color: var(--terminal-accent);
 }
 
 .sidebar-footer {
@@ -144,14 +150,14 @@ body::after {
 }
 
 .sidebar-footer a:hover {
-  color: var(--terminal-cyan);
+  color: var(--terminal-accent);
   background: var(--terminal-dim);
   opacity: 1;
 }
 
 /* Search */
 .sidebar-search input {
-  background: rgba(0, 229, 255, 0.05);
+  background: var(--terminal-dim);
   border: 1px solid var(--border-color);
   border-radius: 2px;
   color: var(--text-color);
@@ -159,18 +165,22 @@ body::after {
 }
 
 .theme-dark .sidebar-search input {
-  background: rgba(0, 229, 255, 0.05);
+  background: var(--terminal-dim);
   color: var(--text-color);
   border-color: var(--border-color);
 }
 
 .sidebar-search input:focus {
-  border-color: var(--terminal-cyan);
-  box-shadow: 0 0 8px rgba(0, 229, 255, 0.15);
+  border-color: var(--terminal-accent);
+  box-shadow: 0 0 8px rgba(74, 229, 74, 0.15);
 }
 
 .sidebar-search input::placeholder {
-  color: rgba(176, 190, 197, 0.3);
+  color: rgba(0, 0, 0, 0.25);
+}
+
+.theme-dark .sidebar-search input::placeholder {
+  color: rgba(176, 191, 176, 0.3);
 }
 
 /* ---- Toggle ---- */
@@ -203,7 +213,7 @@ body::after {
 
 .feed-item.selected {
   background-color: var(--terminal-dim);
-  box-shadow: inset 3px 0 0 var(--terminal-cyan);
+  box-shadow: inset 3px 0 0 var(--terminal-accent);
   border-radius: 0;
 }
 
@@ -215,30 +225,35 @@ body::after {
   font-family: 'SF Mono', 'Fira Code', 'Cascadia Code', 'Courier New', monospace;
   font-size: 1.4rem;
   line-height: 1.35;
-  color: var(--terminal-cyan);
+  color: var(--terminal-accent);
   font-weight: 600;
   letter-spacing: -0.01em;
 }
 
 .item-title:hover {
-  color: #ffffff;
-  text-shadow: 0 0 12px rgba(0, 229, 255, 0.3);
   text-decoration: none;
 }
 
+.theme-dark .item-title:hover {
+  color: #ffffff;
+  text-shadow: 0 0 12px rgba(74, 229, 74, 0.3);
+}
+
 .dateline {
-  color: rgba(176, 190, 197, 0.35);
+  color: var(--text-color);
+  opacity: 0.35;
   font-family: inherit;
   font-size: 0.75em;
   letter-spacing: 0.04em;
 }
 
 .dateline a {
-  color: rgba(176, 190, 197, 0.35);
+  color: inherit;
 }
 
 .dateline a:hover {
-  color: var(--terminal-cyan);
+  color: var(--terminal-accent);
+  opacity: 1;
 }
 
 .item-description {
@@ -249,15 +264,15 @@ body::after {
 }
 
 .item-description a {
-  color: var(--terminal-cyan);
+  color: var(--terminal-accent);
 }
 
-.item-description a:hover {
-  text-shadow: 0 0 8px rgba(0, 229, 255, 0.2);
+.theme-dark .item-description a:hover {
+  text-shadow: 0 0 8px rgba(74, 229, 74, 0.2);
 }
 
 .item-description pre {
-  background: rgba(0, 229, 255, 0.04);
+  background: var(--terminal-dim);
   border: 1px solid var(--border-color);
   border-radius: 2px;
   font-family: inherit;
@@ -276,15 +291,18 @@ body::after {
 /* Scrape */
 .scrape-btn {
   font-family: inherit;
-  color: var(--terminal-cyan);
+  color: var(--terminal-accent);
   border-color: var(--border-color);
   background: transparent;
   border-radius: 2px;
 }
 
 .scrape-btn:hover {
-  border-color: var(--terminal-cyan);
-  box-shadow: 0 0 6px rgba(0, 229, 255, 0.15);
+  border-color: var(--terminal-accent);
+}
+
+.theme-dark .scrape-btn:hover {
+  box-shadow: 0 0 6px rgba(74, 229, 74, 0.15);
 }
 
 /* ---- Buttons ---- */
@@ -303,8 +321,8 @@ button,
 
 button:hover,
 .button:hover {
-  border-color: var(--terminal-cyan);
-  color: var(--terminal-cyan);
+  border-color: var(--terminal-accent);
+  color: var(--terminal-accent);
   background: var(--terminal-dim);
 }
 
@@ -317,16 +335,16 @@ button:hover,
 
 .theme-dark button:hover,
 .theme-dark .button:hover {
-  border-color: var(--terminal-cyan);
-  color: var(--terminal-cyan);
+  border-color: var(--terminal-accent);
+  color: var(--terminal-accent);
   background: var(--terminal-dim);
 }
 
 button.active,
 .theme-dark button.active {
-  background: var(--terminal-cyan);
+  background: var(--terminal-accent);
   color: var(--bg-color);
-  border-color: var(--terminal-cyan);
+  border-color: var(--terminal-accent);
 }
 
 /* ---- Settings ---- */
@@ -336,7 +354,7 @@ button.active,
 }
 
 .settings-view h2 {
-  color: var(--terminal-cyan);
+  color: var(--terminal-accent);
   font-weight: 600;
   letter-spacing: 0.05em;
   font-size: 1.5rem;
@@ -364,13 +382,17 @@ button.active,
   color: var(--text-color) !important;
 }
 
+.theme-dark .settings-view h2 {
+  color: var(--terminal-accent) !important;
+}
+
 /* Inputs */
 input[type="text"],
 input[type="url"],
 input[type="search"],
 select {
   font-family: inherit;
-  background: rgba(0, 229, 255, 0.04);
+  background: var(--terminal-dim);
   border: 1px solid var(--border-color);
   border-radius: 2px;
   color: var(--text-color);
@@ -378,8 +400,8 @@ select {
 
 input:focus,
 select:focus {
-  border-color: var(--terminal-cyan);
-  box-shadow: 0 0 8px rgba(0, 229, 255, 0.15);
+  border-color: var(--terminal-accent);
+  box-shadow: 0 0 8px rgba(74, 229, 74, 0.15);
 }
 
 /* Feed list in settings */
@@ -404,12 +426,16 @@ select:focus {
 
 /* Delete button */
 .delete-feed-btn {
-  color: #ff5252 !important;
-  border-color: rgba(255, 82, 82, 0.3) !important;
+  color: var(--terminal-red) !important;
+  border-color: rgba(198, 40, 40, 0.3) !important;
 }
 
 .delete-feed-btn:hover {
-  border-color: #ff5252 !important;
+  border-color: var(--terminal-red) !important;
+  background: rgba(198, 40, 40, 0.06) !important;
+}
+
+.theme-dark .delete-feed-btn:hover {
   box-shadow: 0 0 6px rgba(255, 82, 82, 0.2) !important;
   background: rgba(255, 82, 82, 0.08) !important;
 }
@@ -425,22 +451,31 @@ select:focus {
 }
 
 ::-webkit-scrollbar-thumb {
-  background: rgba(0, 229, 255, 0.15);
+  background: rgba(74, 229, 74, 0.15);
   border-radius: 0;
 }
 
+.theme-dark ::-webkit-scrollbar-thumb {
+  background: rgba(74, 229, 74, 0.15);
+}
+
 ::-webkit-scrollbar-thumb:hover {
-  background: rgba(0, 229, 255, 0.3);
+  background: rgba(74, 229, 74, 0.3);
 }
 
 /* ---- Backdrop ---- */
 .sidebar-backdrop {
-  background: rgba(0, 0, 0, 0.6);
+  background: rgba(240, 242, 240, 0.6);
   backdrop-filter: blur(2px);
 }
 
+.theme-dark .sidebar-backdrop {
+  background: rgba(0, 0, 0, 0.6);
+}
+
 /* ---- Loading/Empty States ---- */
 .loading, .empty {
-  color: rgba(176, 190, 197, 0.4);
+  color: var(--text-color);
+  opacity: 0.4;
   font-family: inherit;
 }
diff --git a/frontend-vanilla/src/main.ts b/frontend-vanilla/src/main.ts
index fa74274..56ae91a 100644
--- a/frontend-vanilla/src/main.ts
+++ b/frontend-vanilla/src/main.ts
@@ -76,6 +76,10 @@ export function renderLayout() {
           -->
         </div>
         <div class="sidebar-footer">
+          <div class="sidebar-quick-controls">
+            <button id="sidebar-theme-toggle" class="sidebar-icon-btn" title="${store.theme === 'light' ? 'Switch to dark mode' : 'Switch to light mode'}">${store.theme === 'light' ? '☽' : '☀'}</button>
+            <button id="sidebar-style-cycle" class="sidebar-icon-btn" title="Style: ${store.styleTheme}">${store.styleTheme === 'default' ? '◯' : '◉'} ${store.styleTheme}</button>
+          </div>
           <a href="/v3/settings" data-nav="settings">Settings</a>
           <a href="#" id="logout-button">Logout</a>
         </div>
@@ -104,6 +108,18 @@ export function attachLayoutListeners() {
     logout();
   });
 
+  // Sidebar quick controls: light/dark toggle
+  document.getElementById('sidebar-theme-toggle')?.addEventListener('click', () => {
+    store.setTheme(store.theme === 'light' ? 'dark' : 'light');
+  });
+
+  // Sidebar quick controls: cycle style theme
+  document.getElementById('sidebar-style-cycle')?.addEventListener('click', () => {
+    const idx = STYLE_THEMES.indexOf(store.styleTheme as typeof STYLE_THEMES[number]);
+    const next = STYLE_THEMES[(idx + 1) % STYLE_THEMES.length];
+    store.setStyleTheme(next);
+  });
+
   document.getElementById('sidebar-toggle-btn')?.addEventListener('click', () => {
     store.toggleSidebar();
   });
@@ -864,6 +880,12 @@ store.on('theme-updated', () => {
     // Re-apply classes with proper specificity logic
     appEl.className = `theme-${store.theme} font-${store.fontTheme} heading-font-${store.headingFontTheme}`;
   }
+  // Update sidebar toggle icon
+  const toggleBtn = document.getElementById('sidebar-theme-toggle');
+  if (toggleBtn) {
+    toggleBtn.textContent = store.theme === 'light' ? '☽' : '☀';
+    toggleBtn.title = store.theme === 'light' ? 'Switch to dark mode' : 'Switch to light mode';
+  }
   // Also re-render settings if we are on settings page to update active state of buttons
   if (router.getCurrentRoute().path === '/settings') {
     renderSettings();
@@ -885,6 +907,12 @@ store.on('sidebar-toggle', () => {
 
 store.on('style-theme-updated', () => {
   loadStyleTheme(store.styleTheme);
+  // Update sidebar style cycle button
+  const cycleBtn = document.getElementById('sidebar-style-cycle');
+  if (cycleBtn) {
+    cycleBtn.textContent = `${store.styleTheme === 'default' ? '◯' : '◉'} ${store.styleTheme}`;
+    cycleBtn.title = `Style: ${store.styleTheme}`;
+  }
   // Re-render settings if on settings page to update active state
   if (router.getCurrentRoute().path === '/settings') {
     renderSettings();
diff --git a/frontend-vanilla/src/style.css b/frontend-vanilla/src/style.css
index e9512b7..3061948 100644
--- a/frontend-vanilla/src/style.css
+++ b/frontend-vanilla/src/style.css
@@ -215,6 +215,47 @@ html {
   opacity: 1;
 }
 
+/* Quick controls row in sidebar footer */
+.sidebar-quick-controls {
+  display: flex;
+  gap: 0.4rem;
+  margin-bottom: 0.25rem;
+}
+
+.sidebar-icon-btn {
+  background: none;
+  border: none;
+  cursor: pointer;
+  font-size: 0.75rem;
+  padding: 0.3rem 0.6rem;
+  border-radius: 6px;
+  color: var(--text-color);
+  opacity: 0.5;
+  transition: opacity 0.15s, background 0.15s;
+  font-family: var(--font-sans);
+  text-transform: none;
+  font-weight: 500;
+  height: auto;
+  line-height: 1.3;
+}
+
+.sidebar-icon-btn:hover {
+  opacity: 1;
+  background: rgba(255, 255, 255, 0.08);
+  border: none;
+}
+
+.theme-dark .sidebar-icon-btn {
+  color: rgba(0, 0, 0, 0.87);
+  border: none;
+  background: none;
+}
+
+.theme-dark .sidebar-icon-btn:hover {
+  background: rgba(0, 0, 0, 0.06);
+  border: none;
+}
+
 /* Main Content area - always fills full width (sidebar overlays) */
 .main-content {
   width: 100%;