Fix 1px black border in video thumbnails

internal/assets/static/main.css

@@ -569,7 +569,7 @@ body {
 
 .video-thumbnail {
     width: 100%;
-    aspect-ratio: 16 / 9;
+    aspect-ratio: 16 / 8.9;
     object-fit: cover;
     border-radius: var(--border-radius) var(--border-radius) 0 0;
 }