diff --git a/public/core.js b/public/core.js
index 16a743a..4f10a10 100644
--- a/public/core.js
+++ b/public/core.js
@@ -26,6 +26,7 @@ window.MusicRoom = {
   preMuteVolume: 1,
   STORAGE_KEY: "blastoise_volume",
   CHANNEL_STORAGE_KEY: "blastoise_channel",
+  THEME_STORAGE_KEY: "blastoise_theme",
   
   // Playback state
   localTimestamp: 0,
@@ -71,17 +72,25 @@ window.MusicRoom = {
   const M = window.MusicRoom;
   const CHANNEL_COOKIE_MAX_AGE = 60 * 60 * 24 * 400;
 
-  function getCookie(name) {
+  M.getCookieValue = function(name) {
     const prefix = `${name}=`;
     return document.cookie
       .split(";")
       .map(cookie => cookie.trim())
       .find(cookie => cookie.startsWith(prefix))
       ?.slice(prefix.length) || null;
-  }
+  };
+
+  M.setCookieValue = function(name, value, maxAge = CHANNEL_COOKIE_MAX_AGE) {
+    document.cookie = `${name}=${encodeURIComponent(value)}; Path=/; SameSite=Lax; Max-Age=${maxAge}`;
+  };
+
+  M.clearCookieValue = function(name) {
+    document.cookie = `${name}=; Path=/; SameSite=Lax; Max-Age=0`;
+  };
 
   M.getSavedChannelId = function() {
-    const cookieValue = getCookie(M.CHANNEL_STORAGE_KEY);
+    const cookieValue = M.getCookieValue(M.CHANNEL_STORAGE_KEY);
     if (cookieValue) {
       try {
         return decodeURIComponent(cookieValue);
@@ -103,8 +112,7 @@ window.MusicRoom = {
 
   M.rememberChannel = function(channelId) {
     if (!channelId) return;
-    const encoded = encodeURIComponent(channelId);
-    document.cookie = `${M.CHANNEL_STORAGE_KEY}=${encoded}; Path=/; SameSite=Lax; Max-Age=${CHANNEL_COOKIE_MAX_AGE}`;
+    M.setCookieValue(M.CHANNEL_STORAGE_KEY, channelId);
 
     try {
       localStorage.setItem(M.CHANNEL_STORAGE_KEY, channelId);
@@ -112,7 +120,7 @@ window.MusicRoom = {
   };
 
   M.clearRememberedChannel = function() {
-    document.cookie = `${M.CHANNEL_STORAGE_KEY}=; Path=/; SameSite=Lax; Max-Age=0`;
+    M.clearCookieValue(M.CHANNEL_STORAGE_KEY);
 
     try {
       localStorage.removeItem(M.CHANNEL_STORAGE_KEY);
diff --git a/public/index.html b/public/index.html
index 181dbe0..9e1e80b 100644
--- a/public/index.html
+++ b/public/index.html
@@ -47,7 +47,29 @@
           <button id="btn-logout">logout</button>
         </div>
       </div>
-      <div id="stream-select"></div>
+      <div id="stream-select">
+        <select id="theme-select" title="Theme">
+          <optgroup label="Themes">
+            <option value="default">Default</option>
+            <option value="phosphor">Phosphor Noir</option>
+            <option value="vaporwave">Vaporwave Pool</option>
+            <option value="sunrise">Sunrise Radio</option>
+            <option value="paper">Paper Sleeve</option>
+            <option value="contrast">High Contrast</option>
+            <option value="aquarium">Aquarium Glass</option>
+            <option value="amber">Terminal Amber</option>
+          </optgroup>
+          <optgroup label="Layouts">
+            <option value="compact">Tiny Desk</option>
+            <option value="cinema">Cinema Queue</option>
+          </optgroup>
+          <optgroup label="Bad Ideas">
+            <option value="spreadsheet">Bad Spreadsheet</option>
+            <option value="myspace">MySpace Accident</option>
+            <option value="sideways">Sideways Doomscroll</option>
+          </optgroup>
+        </select>
+      </div>
     </div>
     
     <!-- Mobile tab bar -->
@@ -179,6 +201,7 @@
 </div>
 <script src="/trackStorage.js"></script>
 <script src="/core.js"></script>
+<script src="/themes.js"></script>
 <script src="/utils.js"></script>
 <script src="/trackComponent.js"></script>
 <script src="/trackContainer.js"></script>
diff --git a/public/styles.css b/public/styles.css
index 6a3d5d8..624e5d7 100644
--- a/public/styles.css
+++ b/public/styles.css
@@ -662,3 +662,399 @@ button:hover { background: #333; }
   /* Login panel */
   #login-panel { padding: 1rem; }
 }
+
+/* Theme selector */
+#stream-select { margin-left: auto; }
+#theme-select { min-width: 170px; }
+
+/* Shared theme surfaces */
+body[data-ui-theme]:not([data-ui-theme="default"]) #channels-panel,
+body[data-ui-theme]:not([data-ui-theme="default"]) #library-panel,
+body[data-ui-theme]:not([data-ui-theme="default"]) #queue-panel,
+body[data-ui-theme]:not([data-ui-theme="default"]) #player-bar,
+body[data-ui-theme]:not([data-ui-theme="default"]) #login-panel,
+body[data-ui-theme]:not([data-ui-theme="default"]) .panel-views,
+body[data-ui-theme]:not([data-ui-theme="default"]) #playlist-contents-header,
+body[data-ui-theme]:not([data-ui-theme="default"]) .context-menu,
+body[data-ui-theme]:not([data-ui-theme="default"]) #toast-history {
+  background: var(--panel-bg, #1a1a1a);
+  border-color: var(--panel-border, #333);
+  color: var(--text-color, #eee);
+}
+
+body[data-ui-theme]:not([data-ui-theme="default"]) #site-header h1,
+body[data-ui-theme]:not([data-ui-theme="default"]) h3,
+body[data-ui-theme]:not([data-ui-theme="default"]) .panel-tab.active,
+body[data-ui-theme]:not([data-ui-theme="default"]) #selected-playlist-name {
+  color: var(--heading-color, var(--text-color, #eee));
+}
+
+body[data-ui-theme]:not([data-ui-theme="default"]) button,
+body[data-ui-theme]:not([data-ui-theme="default"]) select,
+body[data-ui-theme]:not([data-ui-theme="default"]) input,
+body[data-ui-theme]:not([data-ui-theme="default"]) .panel-tab,
+body[data-ui-theme]:not([data-ui-theme="default"]) .track-actions .track-menu-btn,
+body[data-ui-theme]:not([data-ui-theme="default"]) .track-actions .track-play-btn,
+body[data-ui-theme]:not([data-ui-theme="default"]) .track-actions .track-preview-btn {
+  background: var(--control-bg, #222);
+  border-color: var(--control-border, #444);
+  color: var(--control-color, var(--text-color, #eee));
+}
+
+body[data-ui-theme]:not([data-ui-theme="default"]) .track:hover,
+body[data-ui-theme]:not([data-ui-theme="default"]) .playlist-item:hover,
+body[data-ui-theme]:not([data-ui-theme="default"]) .context-menu-item:hover {
+  background: var(--hover-bg, #222);
+}
+
+body[data-ui-theme]:not([data-ui-theme="default"]) #queue .track.active,
+body[data-ui-theme]:not([data-ui-theme="default"]) .playlist-item.selected,
+body[data-ui-theme]:not([data-ui-theme="default"]) .mobile-tab.active,
+body[data-ui-theme]:not([data-ui-theme="default"]) .now-playing-bar,
+body[data-ui-theme]:not([data-ui-theme="default"]) .toast {
+  background: var(--active-bg, #2a4a3a);
+  border-color: var(--accent, #4e8);
+  color: var(--active-color, var(--accent, #4e8));
+}
+
+body[data-ui-theme]:not([data-ui-theme="default"]) .track.cached .cache-indicator,
+body[data-ui-theme]:not([data-ui-theme="default"]) #progress-bar.playing.synced,
+body[data-ui-theme]:not([data-ui-theme="default"]) #buffer-bar .segment.available,
+body[data-ui-theme]:not([data-ui-theme="default"]) #sync-indicator.visible {
+  background: var(--accent, #4e8);
+}
+
+body[data-ui-theme]:not([data-ui-theme="default"]) .track.not-cached .cache-indicator,
+body[data-ui-theme]:not([data-ui-theme="default"]) #btn-sync.synced,
+body[data-ui-theme]:not([data-ui-theme="default"]) .toast.toast-warning {
+  color: var(--warning, #ea4);
+}
+
+body[data-ui-theme="phosphor"] {
+  --panel-bg: #07140f;
+  --panel-border: #1f7a48;
+  --text-color: #caf7d9;
+  --heading-color: #73ff9c;
+  --control-bg: #0b1f17;
+  --control-border: #24965a;
+  --control-color: #dfffe8;
+  --hover-bg: #123321;
+  --active-bg: #123d29;
+  --active-color: #8cffad;
+  --accent: #51f080;
+  --warning: #f5de72;
+  background: #020806;
+  color: var(--text-color);
+}
+
+body[data-ui-theme="phosphor"] #app { filter: drop-shadow(0 0 8px rgba(81, 240, 128, 0.12)); }
+body[data-ui-theme="phosphor"] #track-name,
+body[data-ui-theme="phosphor"] #btn-sync.synced.connected { text-shadow: 0 0 10px rgba(81, 240, 128, 0.55); }
+
+body[data-ui-theme="vaporwave"] {
+  --panel-bg: #21123a;
+  --panel-border: #ff71ce;
+  --text-color: #f8d7ff;
+  --heading-color: #05ffa1;
+  --control-bg: #351a54;
+  --control-border: #b967ff;
+  --control-color: #ffffff;
+  --hover-bg: #46206d;
+  --active-bg: #2d567a;
+  --active-color: #05ffa1;
+  --accent: #01cdfe;
+  --warning: #fffb96;
+  background: linear-gradient(135deg, #12091f 0%, #2f1856 46%, #0b4857 100%);
+  color: var(--text-color);
+}
+
+body[data-ui-theme="vaporwave"] #main-content { gap: 0.8rem; }
+body[data-ui-theme="vaporwave"] #channels-panel,
+body[data-ui-theme="vaporwave"] #library-panel,
+body[data-ui-theme="vaporwave"] #queue-panel,
+body[data-ui-theme="vaporwave"] #player-bar { box-shadow: 0 0 22px rgba(1, 205, 254, 0.2), inset 0 0 0 1px rgba(255, 113, 206, 0.22); }
+
+body[data-ui-theme="sunrise"] {
+  --panel-bg: #241b2d;
+  --panel-border: #f18f01;
+  --text-color: #fff0d4;
+  --heading-color: #ffcf56;
+  --control-bg: #3a2340;
+  --control-border: #f45d48;
+  --control-color: #fff7e8;
+  --hover-bg: #50314f;
+  --active-bg: #5f342e;
+  --active-color: #ffd166;
+  --accent: #ff9f1c;
+  --warning: #2ec4b6;
+  background: radial-gradient(circle at 20% 0%, #7a2f5c 0, #2b1838 45%, #101018 100%);
+  color: var(--text-color);
+}
+
+body[data-ui-theme="paper"] {
+  --panel-bg: #f4efe3;
+  --panel-border: #3b3327;
+  --text-color: #1d1a17;
+  --heading-color: #0b0b0b;
+  --control-bg: #fffaf0;
+  --control-border: #5a4a36;
+  --control-color: #1d1a17;
+  --hover-bg: #e5d8bd;
+  --active-bg: #d9c69f;
+  --active-color: #1d1a17;
+  --accent: #285f47;
+  --warning: #a75a00;
+  background: #d7c9aa;
+  color: var(--text-color);
+}
+
+body[data-ui-theme="paper"] #channels-panel,
+body[data-ui-theme="paper"] #library-panel,
+body[data-ui-theme="paper"] #queue-panel,
+body[data-ui-theme="paper"] #player-bar {
+  border: 1px solid var(--panel-border);
+  box-shadow: 4px 4px 0 #3b3327;
+}
+
+body[data-ui-theme="contrast"] {
+  --panel-bg: #000;
+  --panel-border: #fff;
+  --text-color: #fff;
+  --heading-color: #ffff00;
+  --control-bg: #000;
+  --control-border: #fff;
+  --control-color: #fff;
+  --hover-bg: #202020;
+  --active-bg: #ffff00;
+  --active-color: #000;
+  --accent: #00ffff;
+  --warning: #ff00ff;
+  background: #000;
+  color: #fff;
+}
+
+body[data-ui-theme="contrast"] #channels-panel,
+body[data-ui-theme="contrast"] #library-panel,
+body[data-ui-theme="contrast"] #queue-panel,
+body[data-ui-theme="contrast"] #player-bar { border: 2px solid #fff; border-radius: 0; }
+
+body[data-ui-theme="aquarium"] {
+  --panel-bg: rgba(8, 42, 58, 0.86);
+  --panel-border: #52e0c4;
+  --text-color: #d7fff8;
+  --heading-color: #a3fff1;
+  --control-bg: #10394d;
+  --control-border: #59bde0;
+  --control-color: #ebfffb;
+  --hover-bg: #174d62;
+  --active-bg: #0d5f65;
+  --active-color: #adfff0;
+  --accent: #52e0c4;
+  --warning: #ffd166;
+  background: linear-gradient(180deg, #062c45, #03161d);
+  color: var(--text-color);
+}
+
+body[data-ui-theme="aquarium"] #app { backdrop-filter: blur(2px); }
+body[data-ui-theme="aquarium"] #channels-panel,
+body[data-ui-theme="aquarium"] #library-panel,
+body[data-ui-theme="aquarium"] #queue-panel,
+body[data-ui-theme="aquarium"] #player-bar { border: 1px solid rgba(163, 255, 241, 0.42); }
+
+body[data-ui-theme="amber"] {
+  --panel-bg: #1b1204;
+  --panel-border: #8c5d13;
+  --text-color: #ffd98a;
+  --heading-color: #ffb000;
+  --control-bg: #2a1b06;
+  --control-border: #b97919;
+  --control-color: #ffe8ad;
+  --hover-bg: #3a2508;
+  --active-bg: #4c3109;
+  --active-color: #ffc857;
+  --accent: #ffb000;
+  --warning: #f77f00;
+  background: #080502;
+  color: var(--text-color);
+  font-family: "Cascadia Mono", "Consolas", monospace;
+}
+
+body[data-ui-theme="amber"] * { letter-spacing: 0; }
+body[data-ui-theme="amber"] #track-name { text-transform: uppercase; }
+
+body[data-ui-theme="compact"] {
+  --panel-bg: #15181b;
+  --panel-border: #35414a;
+  --text-color: #e6edf3;
+  --heading-color: #9fc7ff;
+  --control-bg: #20262c;
+  --control-border: #3e4d58;
+  --control-color: #edf4fb;
+  --hover-bg: #242c33;
+  --active-bg: #22364b;
+  --active-color: #9fc7ff;
+  --accent: #79c0ff;
+  --warning: #e3b341;
+  background: #0d1117;
+  color: var(--text-color);
+}
+
+body[data-ui-theme="compact"] #app { max-width: 1200px; padding: 0.25rem; }
+body[data-ui-theme="compact"] #main-content { gap: 0.25rem; }
+body[data-ui-theme="compact"] #channels-panel { flex-basis: 130px; }
+body[data-ui-theme="compact"] #library-panel,
+body[data-ui-theme="compact"] #queue-panel { padding: 0.25rem; max-height: 66vh; }
+body[data-ui-theme="compact"] #library .track,
+body[data-ui-theme="compact"] #queue .track,
+body[data-ui-theme="compact"] #playlist-tracks .track { padding: 0.16rem 0.35rem; font-size: 0.78rem; }
+body[data-ui-theme="compact"] #player-bar { padding: 0.35rem 0.5rem; }
+
+body[data-ui-theme="cinema"] {
+  --panel-bg: #101010;
+  --panel-border: #41362a;
+  --text-color: #e8dfcc;
+  --heading-color: #f6c65b;
+  --control-bg: #1f1a15;
+  --control-border: #6d5735;
+  --control-color: #f3ead7;
+  --hover-bg: #292118;
+  --active-bg: #3d2b18;
+  --active-color: #f6c65b;
+  --accent: #f6c65b;
+  --warning: #db5461;
+  background: #050505;
+  color: var(--text-color);
+}
+
+body[data-ui-theme="cinema"] #main-content { display: grid; grid-template-columns: 150px minmax(280px, 0.8fr) minmax(420px, 1.45fr); }
+body[data-ui-theme="cinema"] #queue-panel { order: 3; max-height: 70vh; }
+body[data-ui-theme="cinema"] #queue .track.active { font-size: 1rem; padding: 0.65rem 0.75rem; }
+body[data-ui-theme="cinema"] #player-bar { border-top: 4px solid var(--accent); }
+
+html[data-ui-theme="spreadsheet"],
+html[data-ui-theme="myspace"],
+html[data-ui-theme="sideways"] {
+  max-width: none;
+  overflow-x: auto;
+  overscroll-behavior-x: auto;
+}
+
+html[data-ui-theme="spreadsheet"] { min-width: 2100px; }
+html[data-ui-theme="myspace"] { min-width: 1850px; }
+html[data-ui-theme="sideways"] { min-width: 2600px; }
+
+body[data-ui-theme="spreadsheet"],
+body[data-ui-theme="myspace"],
+body[data-ui-theme="sideways"] {
+  max-width: none;
+  overflow-x: auto;
+}
+
+body[data-ui-theme="spreadsheet"] {
+  --panel-bg: #ffffff;
+  --panel-border: #8b8b8b;
+  --text-color: #000000;
+  --heading-color: #008000;
+  --control-bg: #efefef;
+  --control-border: #777777;
+  --control-color: #000000;
+  --hover-bg: #ffffcc;
+  --active-bg: #00ff00;
+  --active-color: #000000;
+  --accent: #0000ff;
+  --warning: #ff0000;
+  background: #fff;
+  color: #000;
+  font-family: "Times New Roman", serif;
+}
+
+body[data-ui-theme="spreadsheet"] #app { width: 2100px; max-width: none; overflow-x: visible; }
+body[data-ui-theme="spreadsheet"] #main-content { width: 2050px; max-width: none; overflow-x: visible; gap: 0; }
+body[data-ui-theme="spreadsheet"] #channels-panel,
+body[data-ui-theme="spreadsheet"] #library-panel,
+body[data-ui-theme="spreadsheet"] #queue-panel,
+body[data-ui-theme="spreadsheet"] #player-bar {
+  border: 1px solid #000;
+  border-radius: 0;
+  box-shadow: none;
+}
+body[data-ui-theme="spreadsheet"] .track { border-bottom: 1px solid #999; border-radius: 0; }
+body[data-ui-theme="spreadsheet"] #library,
+body[data-ui-theme="spreadsheet"] #queue { overflow-x: scroll; }
+
+body[data-ui-theme="myspace"] {
+  --panel-bg: #220044;
+  --panel-border: #00ff66;
+  --text-color: #ffff00;
+  --heading-color: #ff00ff;
+  --control-bg: #0000cc;
+  --control-border: #ffff00;
+  --control-color: #ffffff;
+  --hover-bg: #ff00ff;
+  --active-bg: #00ffff;
+  --active-color: #000000;
+  --accent: #00ff66;
+  --warning: #ff6600;
+  background: repeating-linear-gradient(45deg, #ff00ff 0 18px, #00ffff 18px 36px, #ffff00 36px 54px);
+  color: var(--text-color);
+  font-family: Impact, "Arial Black", sans-serif;
+}
+
+body[data-ui-theme="myspace"] #app { width: 1850px; max-width: none; overflow-x: visible; transform: rotate(-0.35deg); }
+body[data-ui-theme="myspace"] #main-content { width: 1780px; max-width: none; overflow-x: visible; gap: 1.25rem; }
+body[data-ui-theme="myspace"] #channels-panel,
+body[data-ui-theme="myspace"] #library-panel,
+body[data-ui-theme="myspace"] #queue-panel,
+body[data-ui-theme="myspace"] #player-bar {
+  border: 6px ridge #00ff66;
+  border-radius: 22px;
+  box-shadow: 12px 12px 0 #ff00ff, -9px -7px 0 #00ffff;
+}
+body[data-ui-theme="myspace"] .track:nth-child(odd) { transform: rotate(0.45deg); }
+body[data-ui-theme="myspace"] .track:nth-child(even) { transform: rotate(-0.45deg); }
+body[data-ui-theme="myspace"] #track-name { font-size: 1.25rem; color: #00ff66; text-shadow: 2px 2px #ff00ff; }
+
+body[data-ui-theme="sideways"] {
+  --panel-bg: #241313;
+  --panel-border: #cc3333;
+  --text-color: #f8dcdc;
+  --heading-color: #ff6b35;
+  --control-bg: #351b1b;
+  --control-border: #8c2f39;
+  --control-color: #fff1f1;
+  --hover-bg: #482121;
+  --active-bg: #5a231f;
+  --active-color: #ffb199;
+  --accent: #ff6b35;
+  --warning: #ffd166;
+  background: #190b0b;
+  color: var(--text-color);
+}
+
+body[data-ui-theme="sideways"] #app { width: 2600px; max-width: none; overflow-x: visible; }
+body[data-ui-theme="sideways"] #main-content {
+  width: 2480px;
+  max-width: none;
+  display: grid;
+  grid-template-columns: 260px 1060px 1060px;
+  overflow-x: visible;
+}
+body[data-ui-theme="sideways"] #channels-panel,
+body[data-ui-theme="sideways"] #library-panel,
+body[data-ui-theme="sideways"] #queue-panel { max-height: 42vh; }
+body[data-ui-theme="sideways"] #player-bar { width: 2480px; max-width: none; }
+
+@media (max-width: 768px) {
+  #stream-select { width: 100%; margin-left: 0; }
+  #theme-select { width: 100%; min-height: 44px; }
+
+  body[data-ui-theme="compact"] #app,
+  body[data-ui-theme="cinema"] #app {
+    max-width: 100%;
+  }
+
+  body[data-ui-theme="cinema"] #main-content {
+    display: flex;
+    grid-template-columns: none;
+  }
+}
diff --git a/public/themes.js b/public/themes.js
new file mode 100644
index 0000000..b68b6eb
--- /dev/null
+++ b/public/themes.js
@@ -0,0 +1,90 @@
+// MusicRoom - UI theme and layout experiments
+
+(function() {
+  const M = window.MusicRoom;
+
+  const THEMES = new Set([
+    "default",
+    "phosphor",
+    "vaporwave",
+    "sunrise",
+    "paper",
+    "contrast",
+    "aquarium",
+    "amber",
+    "compact",
+    "cinema",
+    "spreadsheet",
+    "myspace",
+    "sideways"
+  ]);
+
+  function decodeCookieValue(value) {
+    if (!value) return null;
+    try {
+      return decodeURIComponent(value);
+    } catch {
+      M.clearCookieValue(M.THEME_STORAGE_KEY);
+      return null;
+    }
+  }
+
+  function normalizeTheme(theme) {
+    return THEMES.has(theme) ? theme : "default";
+  }
+
+  M.getSavedTheme = function() {
+    const cookieTheme = normalizeTheme(decodeCookieValue(M.getCookieValue(M.THEME_STORAGE_KEY)));
+    if (cookieTheme !== "default") return cookieTheme;
+
+    try {
+      const storedTheme = normalizeTheme(localStorage.getItem(M.THEME_STORAGE_KEY));
+      if (storedTheme !== "default") {
+        M.rememberTheme(storedTheme);
+        return storedTheme;
+      }
+    } catch {}
+
+    return "default";
+  };
+
+  M.rememberTheme = function(theme) {
+    const normalized = normalizeTheme(theme);
+    if (normalized === "default") {
+      M.clearThemePreference();
+      return;
+    }
+
+    M.setCookieValue(M.THEME_STORAGE_KEY, normalized);
+    try {
+      localStorage.setItem(M.THEME_STORAGE_KEY, normalized);
+    } catch {}
+  };
+
+  M.clearThemePreference = function() {
+    M.clearCookieValue(M.THEME_STORAGE_KEY);
+    try {
+      localStorage.removeItem(M.THEME_STORAGE_KEY);
+    } catch {}
+  };
+
+  M.applyTheme = function(theme, remember = true) {
+    const normalized = normalizeTheme(theme);
+    document.documentElement.dataset.uiTheme = normalized;
+    document.body.dataset.uiTheme = normalized;
+
+    const selector = document.getElementById("theme-select");
+    if (selector) selector.value = normalized;
+
+    if (remember) M.rememberTheme(normalized);
+  };
+
+  document.addEventListener("DOMContentLoaded", () => {
+    const selector = document.getElementById("theme-select");
+    M.applyTheme(M.getSavedTheme(), false);
+
+    if (selector) {
+      selector.onchange = () => M.applyTheme(selector.value);
+    }
+  });
+})();