[mirotalksfu] - improve init UI

public/css/VideoGrid.css

@@ -172,15 +172,6 @@
     border-radius: '10px';
 }
 
-.init-container {
-    position: relative;
-}
-.init-container video {
-    z-index: 0;
-    position: relative;
-    height: 240px;
-}
-
 video {
     width: 100%;
     height: 100%;