feat: add card layout controls to extension popup

Co-authored-by: Cursor <cursoragent@cursor.com>

popup/popup.html

@@ -28,6 +28,27 @@
       </select>
     </div>
 
+    <div class="section">
+      <h2>Card Layout</h2>
+      <label class="toggle-row">
+        <span>Enable card layout</span>
+        <input type="checkbox" id="cardLayout">
+      </label>
+      <label for="cardBackground">Background Style</label>
+      <select id="cardBackground">
+        <option value="reddit">Reddit Default</option>
+        <option value="shadcn">shadcn Style</option>
+      </select>
+      <label for="cardGap">Card Spacing</label>
+      <select id="cardGap">
+        <option value="8">8px</option>
+        <option value="12">12px</option>
+        <option value="16">16px</option>
+        <option value="24">24px</option>
+        <option value="32">32px</option>
+      </select>
+    </div>
+
     <div class="section">
       <h2>Light Mode Colors</h2>
       <fieldset>