app.css

body {
  background-color: #000;
  color: #fff;
  font-family: "Arial", Times, serif;
  font-size: 12px;
}

#spectrogram:hover {
  cursor: pointer;
}

.label {
  font-weight: bold;
  text-align: right;
}

a {
  color: #fff;
}

button {
  width: 5rem;
  font-size: 12px;
}

#source {
  font-size: 12px;
}

input[type=range] {
  -webkit-appearance: none;
  appearance: none;
  border-radius: 10px;
  height: 10px;
  width: 8rem;
}

#controls {
  margin-left: auto;
  margin-right: auto;
}

#smoothing-value, #threshold-value {
  font-family: monospace;
  color: #888888;
}

#pianolizer {
  position: relative;
  text-align: center;
}

#help {
  position: absolute;
  top: 50%;
  transform: translateY(-50%);
  left: 0;
  right: 0;
  z-index: -1;
  overflow: hidden;
}

.piano-key {
  stroke: #555555; /* also defined in js/visualization.js! */
  fill: #000;
}

.piano-key-label {
  fill: #555555; /* also defined in js/visualization.js! */
  font-family: monospace;
  font-size: 12px;
}

#footer {
  text-align: center;
}