body { font-family: sans-serif; padding: 20px; }
.container { max-width: 600px; margin: auto; }
video { width: 100%; margin: 10px 0; }
.trimmer { position: relative; width: 100%; height: 20px; background: #ddd; margin: 10px 0; }
.draggable-bar {
  position: absolute; top: 0; width: 4px; height: 100%;
  background: red; cursor: ew-resize;
}
#startTrimBar { left: 0; }
#endTrimBar { right: 0; }