修改页面中缩略图和视频的加载策略，提高加载速度

@@ -12,6 +12,8 @@ interface ImageCardProps {
 
 const ImageCard: React.FC<ImageCardProps> = ({ image, onClick, onLike, currentUser, isVideo = false }) => {
   const [isLoaded, setIsLoaded] = useState(false);
+  const [isHovered, setIsHovered] = useState(false);
+  const [videoStarted, setVideoStarted] = useState(false);
   const videoRef = useRef<HTMLVideoElement>(null);
 
   const handleLike = (e: React.MouseEvent) => {
@@ -20,60 +22,75 @@ const ImageCard: React.FC<ImageCardProps> = ({ image, onClick, onLike, currentUs
   };
   
   const handleMouseEnter = () => {
-    if (videoRef.current) {
-      videoRef.current.currentTime = 0;
-      videoRef.current.play().catch(e => console.error("Video play failed", e));
-    }
+    setIsHovered(true);
+    // Video will be played via autoPlay once rendered
   }
 
   const handleMouseLeave = () => {
-    if (videoRef.current) {
-      videoRef.current.pause();
-      videoRef.current.currentTime = videoRef.current.duration || 0;
-    }
+    setIsHovered(false);
+    setVideoStarted(false);
   }
 
-  const handleVideoMetadata = () => {
-    if (videoRef.current) {
-      videoRef.current.currentTime = videoRef.current.duration || 0;
-    }
-  }
-
-  // If it's a video with a thumbnail, we want to show it immediately (via poster)
-  // instead of waiting for the video file to load metadata.
+  // Content is considered "ready" if the main image/video is loaded 
+  // OR if we have a thumbnail to show for a video.
   const showContent = isLoaded || (isVideo && !!image.thumbnail);
 
   return (
     <div 
-      className="group relative mb-4 break-inside-avoid rounded-2xl overflow-hidden bg-gray-200 cursor-zoom-in shadow-sm hover:shadow-xl transition-all duration-300"
+      className="group relative mb-4 break-inside-avoid rounded-2xl overflow-hidden bg-gray-100 cursor-zoom-in shadow-sm hover:shadow-xl transition-all duration-300"
       onClick={() => onClick(image)}
       onMouseEnter={handleMouseEnter}
       onMouseLeave={handleMouseLeave}
     >
       {/* Placeholder / Skeleton */}
       {!showContent && (
-        <div className="absolute inset-0 bg-gray-200 animate-pulse min-h-[200px]" />
+        <div className="absolute inset-0 bg-gray-200 animate-pulse min-h-[150px]" />
       )}
 
       {/* Main Content */}
       {isVideo ? (
-        <video
-          ref={videoRef}
-          src={image.url}
-          poster={image.thumbnail} // Use thumbnail as poster
-          className={`w-full h-auto object-cover transition-opacity duration-300 ${showContent ? 'opacity-100' : 'opacity-0'}`}
-          onLoadedMetadata={handleVideoMetadata}
-          onLoadedData={() => setIsLoaded(true)}
-          loop
-          muted
-          playsInline
-          preload="metadata"
-        />
+        <div className="relative w-full overflow-hidden bg-gray-100">
+          {/* Always show thumbnail first */}
+          <img
+            src={image.thumbnail || (isVideo ? '' : image.url)}
+            alt={image.prompt}
+            className={`w-full h-auto object-cover transition-opacity duration-500 ${videoStarted ? 'opacity-0' : 'opacity-100'} ${!image.thumbnail && isVideo ? 'opacity-0' : ''}`}
+            onLoad={() => setIsLoaded(true)}
+            loading="lazy"
+          />
+          
+          {isVideo && !image.thumbnail && !videoStarted && (
+             <div className="absolute inset-0 flex items-center justify-center bg-gray-200 text-gray-400">
+                <Video size={32} />
+             </div>
+          )}
+          
+          {/* Load video only on hover */}
+          {isHovered && (
+            <video
+              ref={videoRef}
+              src={image.url}
+              className={`absolute inset-0 w-full h-full object-cover transition-opacity duration-300 ${videoStarted ? 'opacity-100' : 'opacity-0'}`}
+              onLoadedData={() => setVideoStarted(true)}
+              autoPlay
+              loop
+              muted
+              playsInline
+            />
+          )}
+          
+          {/* Video Indicator Icon (When not hovered) */}
+          {!isHovered && (
+            <div className="absolute top-3 left-3 p-1.5 bg-black/30 backdrop-blur-md rounded-lg text-white/90">
+              <Video size={14} />
+            </div>
+          )}
+        </div>
       ) : (
         <img
           src={image.url}
           alt={image.prompt}
-          className={`w-full h-auto object-cover transition-transform duration-700 ease-in-out group-hover:scale-105 ${showContent ? 'opacity-100' : 'opacity-0'}`}
+          className={`w-full h-auto object-cover transition-transform duration-700 ease-in-out group-hover:scale-105 ${isLoaded ? 'opacity-100' : 'opacity-0'}`}
           onLoad={() => setIsLoaded(true)}
           loading="lazy"
         />