.edge-pattern {
  position: fixed;
  top: -50vh;
  left: 0;
  width: 600px;          /* width of the visible edge strip */
  height: 200vh;
  pointer-events: none;

  background-image: url("images/edge-pattern.png");
  background-repeat: repeat-y;

  background-size: auto 1200px;   /* 🔥 BIG BOI SCALE */
  background-position: center top;

  opacity: 0.3;
  z-index: 999999;
  will-change: transform;
}
#recordBtn.recording {
  background: #c62828;
  color: white;
  box-shadow: 0 0 14px #ff3b3b;
}