.visualizer {
  position: fixed;
  bottom: 0;
  width: 100%;
  height: 100px;
  display: flex;
  align-items: flex-end;
  justify-content: flex-start;
  background: transparent;
  z-index: 10;
  pointer-events: none;
}

.visualizer-bar {
  background-color: rgba(255, 255, 255, 0.15);
  border-radius: 2px;
  transition: height 0.1s ease;
  /* ancho se controla por JS */
}