[mirotalksfu] - fix css

public/css/VideoGrid.css

@@ -5,16 +5,14 @@
 #videoMediaContainer {
     z-index: 1;
     display: flex;
+    width: 100%;
+    height: 100%;
     align-content: center;
     flex-wrap: wrap;
     align-items: center;
     justify-content: center;
     vertical-align: middle;
     position: absolute;
-    left: 0px;
-    bottom: 0px;
-    top: 0px;
-    right: 0px;
 }
 
 .Camera {