feat: update video content and improve grid layout

- Add new video thumbnails for music, game, tech, and art categories
- Update video data with more realistic content
- Adjust grid layout dimensions for better responsiveness
- Simplify category buttons in the UI
- Remove unused maxresdefault.jpg cover image

index.html

@@ -172,13 +172,10 @@
                     <button class="category-btn active">All</button>
                     <button class="category-btn">Music</button>
                     <button class="category-btn">Game</button>
-                    <button class="category-btn">Live</button>
-                    <button class="category-btn">Album</button>
-                    <button class="category-btn">Animation</button>
+                    <button class="category-btn">Technology</button>
                     <button class="category-btn">Art</button>
                     <button class="category-btn">Recently Uploaded</button>
                     <button class="category-btn">Watched</button>
-                    <button class="category-btn">New</button>
                 </div>
                 
                 <!-- 横屏视频 -->