scrapes from all open tabs.

src/viewer/viewer.css

@@ -40,6 +40,25 @@ body {
   opacity: 0.3;
 }
 
+.panel-label {
+  position: absolute;
+  bottom: 6px;
+  left: 8px;
+  right: 8px;
+  background: rgba(0, 0, 0, 0.7);
+  color: #e2e8f0;
+  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
+  font-size: 11px;
+  padding: 3px 8px;
+  border-radius: 4px;
+  overflow: hidden;
+  white-space: nowrap;
+  text-overflow: ellipsis;
+  z-index: 10;
+  pointer-events: none;
+  text-align: center;
+}
+
 .panel.empty::after {
   content: 'No video';
   color: #64748b;