make call buttons round for consistency with other apps

css/base.css

@@ -1605,13 +1605,26 @@ img.channel {
 }
 
 .controls {
+  position: absolute;
   display: flex;
+  column-gap: 1rem;
   align-items: center;
   justify-content: center;
-  height: 3.2rem;
+  width: 100%;
+  bottom: 2.5rem;
   z-index: 1;
-  background-color: #eceff1;
-  box-shadow: 0px -2px 3px -1px rgba(0,0,0,0.1); /* Faint shadow above panel */
+}
+
+.incoming-call .controls {
+  bottom: 1rem;
+}
+
+.controls button {
+  border-radius: 50%;
+  width: 4rem;
+  height: 4rem;
+  min-width: initial;
+  box-shadow: 0 3px 6px 0 rgba(0, 0, 0, 0.25);
 }
 
 #video-container-panel {
@@ -1745,7 +1758,7 @@ video {
   left: initial;
   width: 100%;
   height: 100%;
-  padding: 5rem 3.5rem 2rem 3.5rem;
+  padding: 4rem 3.5rem 5.5rem 3.5rem;
   display: flex;
   align-items: center;
   justify-content: center;