diff --git a/demo/app-root.ts b/demo/app-root.ts
index 89f9ab1..ef6498b 100644
--- a/demo/app-root.ts
+++ b/demo/app-root.ts
@@ -6,11 +6,11 @@ import { unsafeHTML } from 'lit/directives/unsafe-html.js';
 
 const storyModules = import.meta.glob(
   ['../src/elements/**/*-story.ts', '../src/labs/**/*-story.ts'],
-  { eager: true }
+  { eager: true },
 );
 
 const storyEntries = Object.keys(storyModules)
-  .map(path => {
+  .map((path) => {
     const labs = path.includes('/src/labs/');
     const parts = path.split('/');
     const filename = parts[parts.length - 1]; // e.g. "ia-button-story.ts"
@@ -19,13 +19,15 @@ const storyEntries = Object.keys(storyModules)
   })
   .sort((a, b) => a.tag.localeCompare(b.tag));
 
-const productionEntries = storyEntries.filter(e => !e.labs);
-const labsEntries = storyEntries.filter(e => e.labs);
+const productionEntries = storyEntries.filter((e) => !e.labs);
+const labsEntries = storyEntries.filter((e) => e.labs);
 const ALL_ENTRIES = [...productionEntries, ...labsEntries];
 
 @customElement('app-root')
 export class AppRoot extends LitElement {
-  createRenderRoot() { return this; }
+  createRenderRoot() {
+    return this;
+  }
 
   private _observer?: IntersectionObserver;
   private _abortController = new AbortController();
@@ -34,33 +36,63 @@ export class AppRoot extends LitElement {
     return html`
       <nav id="ia-sidebar">
         <h2>Production-Ready</h2>
-        ${productionEntries.map(e => html`<a href="#${e.id}">&lt;${e.tag}&gt;</a>`)}
+        ${productionEntries.map(
+          (e) => html`<a href="#${e.id}">&lt;${e.tag}&gt;</a>`,
+        )}
         <h2>Labs 🧪</h2>
-        ${labsEntries.map(e => html`<a href="#${e.id}">&lt;${e.tag}&gt;</a>`)}
+        ${labsEntries.map((e) => html`<a href="#${e.id}">&lt;${e.tag}&gt;</a>`)}
       </nav>
       <div id="ia-content">
         <h1>Internet Archive Elements</h1>
+
+        <fieldset>
+          <legend>Settings</legend>
+          <label for="darkModeToggle">Dark Mode</label>
+          <input
+            id="darkModeToggle"
+            type="checkbox"
+            switch
+            @change=${this.toggleDarkMode}
+          />
+        </fieldset>
+
         <h2>Production-Ready Elements</h2>
-        ${productionEntries.map(e => html`
-          <div id="${e.id}" class="ia-anchor">
-            ${unsafeHTML(`<${e.storyTag}></${e.storyTag}>`)}
-          </div>
-        `)}
+        ${productionEntries.map(
+          (e) => html`
+            <div id="${e.id}" class="ia-anchor">
+              ${unsafeHTML(`<${e.storyTag}></${e.storyTag}>`)}
+            </div>
+          `,
+        )}
         <h2>Labs Elements</h2>
-        ${labsEntries.map(e => html`
-          <div id="${e.id}" class="ia-anchor">
-            ${unsafeHTML(`<${e.storyTag}></${e.storyTag}>`)}
-          </div>
-        `)}
+        ${labsEntries.map(
+          (e) => html`
+            <div id="${e.id}" class="ia-anchor">
+              ${unsafeHTML(`<${e.storyTag}></${e.storyTag}>`)}
+            </div>
+          `,
+        )}
       </div>
     `;
   }
 
+  private toggleDarkMode(event: Event) {
+    const checkbox = event.target as HTMLInputElement;
+    if (checkbox.checked) {
+      document.documentElement.classList.add('dark');
+    } else {
+      document.documentElement.classList.remove('dark');
+    }
+  }
+
   firstUpdated() {
-    const allIds = ALL_ENTRIES.map(e => e.id);
+    const allIds = ALL_ENTRIES.map((e) => e.id);
 
     const links = Object.fromEntries(
-      allIds.map(id => [id, this.querySelector(`#ia-sidebar a[href="#${id}"]`)])
+      allIds.map((id) => [
+        id,
+        this.querySelector(`#ia-sidebar a[href="#${id}"]`),
+      ]),
     );
 
     const visible = new Set<string>();
@@ -68,31 +100,37 @@ export class AppRoot extends LitElement {
     // Only anchors in the top 30% of the viewport count as "active".
     // The first (topmost) visible anchor wins.
     this._observer = new IntersectionObserver(
-      entries => {
+      (entries) => {
         for (const entry of entries) {
           if (entry.isIntersecting) visible.add(entry.target.id);
           else visible.delete(entry.target.id);
         }
-        const activeId = allIds.find(id => visible.has(id)) ?? allIds[0];
-        allIds.forEach(id => links[id]?.classList.toggle('active', id === activeId));
+        const activeId = allIds.find((id) => visible.has(id)) ?? allIds[0];
+        allIds.forEach((id) =>
+          links[id]?.classList.toggle('active', id === activeId),
+        );
       },
       { rootMargin: '0px 0px -70% 0px' },
     );
 
-    allIds.forEach(id => {
+    allIds.forEach((id) => {
       const el = document.getElementById(id);
       if (el) this._observer!.observe(el);
     });
 
-    allIds.forEach(id => {
-      links[id]?.addEventListener('click', (e: Event) => {
-        e.preventDefault();
-        const el = document.getElementById(id);
-        if (el) {
-          const top = el.getBoundingClientRect().top + window.scrollY;
-          window.scrollTo({ top: Math.max(0, top - 16), behavior: 'smooth' });
-        }
-      }, { signal: this._abortController.signal });
+    allIds.forEach((id) => {
+      links[id]?.addEventListener(
+        'click',
+        (e: Event) => {
+          e.preventDefault();
+          const el = document.getElementById(id);
+          if (el) {
+            const top = el.getBoundingClientRect().top + window.scrollY;
+            window.scrollTo({ top: Math.max(0, top - 16), behavior: 'smooth' });
+          }
+        },
+        { signal: this._abortController.signal },
+      );
     });
   }
 
diff --git a/demo/index.css b/demo/index.css
index 560264d..3b1acd4 100644
--- a/demo/index.css
+++ b/demo/index.css
@@ -13,9 +13,23 @@
   -moz-osx-font-smoothing: grayscale;
 }
 
+:root.dark {
+  color-scheme: dark;
+  color: rgba(255, 255, 255, 0.87);
+  background-color: #242424;
+
+  --ia-theme-primary-background-color: #242424;
+  --ia-theme-secondary-background-color: #1e1e1e;
+  --ia-theme-primary-text-color: rgba(255, 255, 255, 0.87);
+  --ia-theme-secondary-text-color: #a0a0a0;
+  --ia-theme-link-color: #4b64ff;
+  --ia-theme-primary-cta-fill: #4b64ff;
+  --ia-theme-primary-cta-text-color: #ffffff;
+}
+
 a {
   font-weight: 500;
-  color: #646cff;
+  color: var(--ia-theme-link-color);
   text-decoration: inherit;
 }
 
diff --git a/demo/story-template.ts b/demo/story-template.ts
index d0871cc..a07c78e 100644
--- a/demo/story-template.ts
+++ b/demo/story-template.ts
@@ -390,6 +390,14 @@ export class StoryTemplate extends LitElement {
           padding: 0.5em;
         }
 
+        .disclosure-arrow {
+          width: 12px;
+          height: 12px;
+          transform: rotate(-90deg);
+          transition: transform 0.2s ease-in-out;
+          filter: invert(0.5);
+        }
+
         .slot-container.hidden {
           display: none;
         }