load more button and other device support

frontend/style.css

@@ -122,6 +122,11 @@ body.theme-light {
     color: var(--accent);
 }
 
+:focus-visible {
+    outline: 2px solid var(--accent);
+    outline-offset: 2px;
+}
+
 /* CDN-served icon images (Heroicons) */
 .icon-svg {
     width: 24px;
@@ -450,6 +455,34 @@ body.theme-light .setting-item select option {
     display: block;
 }
 
+.load-more-btn {
+    position: sticky;
+    left: 50%;
+    transform: translateX(-50%);
+    margin: 16px auto 32px auto;
+    width: 52px;
+    height: 52px;
+    border-radius: 999px;
+    border: 1px solid var(--border);
+    background: var(--bg-secondary);
+    color: var(--text-primary);
+    display: flex;
+    align-items: center;
+    justify-content: center;
+    cursor: pointer;
+    transition: all 0.2s ease;
+    z-index: 10;
+}
+
+.load-more-btn:hover {
+    background: var(--bg-tertiary);
+}
+
+.load-more-btn:disabled {
+    opacity: 0.5;
+    cursor: not-allowed;
+}
+
 /* Grid Container */
 .grid-container {
     display: grid;
@@ -465,6 +498,88 @@ body.theme-light .setting-item select option {
         gap: 12px;
         padding: 16px;
     }
+
+    .top-bar {
+        flex-wrap: wrap;
+        height: auto;
+        padding: 12px 16px;
+    }
+
+    .search-container {
+        order: 3;
+        width: 100%;
+        max-width: 100%;
+    }
+
+    .actions {
+        order: 2;
+        width: 100%;
+        justify-content: flex-end;
+    }
+}
+
+@media (max-width: 480px) {
+    .logo {
+        font-size: 18px;
+    }
+
+    .icon-btn {
+        width: 44px;
+        height: 44px;
+    }
+}
+
+@media (min-width: 1600px) {
+    body {
+        font-size: 16px;
+    }
+
+    .top-bar {
+        height: 72px;
+        padding: 0 36px;
+    }
+
+    .grid-container {
+        gap: 24px;
+        padding: 32px 48px;
+    }
+
+    .video-card h4 {
+        font-size: 16px;
+    }
+
+    .video-card p {
+        font-size: 13px;
+    }
+}
+
+@media (min-width: 1920px) {
+    .grid-container {
+        grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
+    }
+}
+
+@media (pointer: coarse) {
+    .icon-btn {
+        width: 52px;
+        height: 52px;
+    }
+
+    .btn-secondary {
+        padding: 10px 14px;
+    }
+
+    .setting-item select,
+    .input-row input {
+        padding: 10px 14px;
+    }
+}
+
+@media (prefers-reduced-motion: reduce) {
+    * {
+        transition: none !important;
+        animation: none !important;
+    }
 }
 
 /* Video Card */