* {
  font-family: "Helvetica Neue", Arial, sans-serif;
  box-sizing: border-box;
  padding: 0;
  margin: 0;
}
:root {
  --primary-color: #333;
  --secondary-color: #f0f0f0;
  --highlight-color: #e0e0e0;
  --active-color: #d0d0d0;
  --border-color: #ccc;
  --hover-border-color: #999;
  --active-border-color: #888;
  --shadow-color: rgba(0, 0, 0, 0.1);
  --hover-shadow-color: rgba(0, 0, 0, 0.2);
  --font-size: 14px;
  --transition-speed: 0.3s;
  --button-padding: 10px 20px;
}
h2 {
  margin-left: 13px;
  padding: 15px 0px;
}
.container,
.buttons {
  margin-bottom: 20px;
}
.time-display {
  display: inline-block;
  margin-left: 50px;
  font-size: 28px;
  color: lightgray;
}
.volume-slider {
  margin-bottom: -3px;
  margin-left: 5px;
}
.chart-container {
  position: relative;
  height: 1000px;
}
.chart {
  display: none;
  position: absolute;
}
.line,
.onset-line {
  fill: none;
  stroke-width: 3px;
}
.axis path,
.axis line {
  stroke: var(--primary-color);
}
.axis text {
  font-size: 12px;
  fill: var(--primary-color);
}
.toggle-button {
  margin: 5px;
  padding: var(--button-padding);
  font-size: var(--font-size);
  cursor: pointer;
  border-radius: 5px;
  transition: background-color var(--transition-speed) ease,
    border-color var(--transition-speed) ease, transform 0.2s ease,
    box-shadow var(--transition-speed) ease;
  box-shadow: 0 2px 4px var(--shadow-color);
  border: 2px solid black;
}
.toggle-button:hover {
  transform: translateY(-2px);
  box-shadow: 0 4px 8px var(--hover-shadow-color);
}
.toggle-button:active {
  transform: translateY(0);
  box-shadow: 0 2px 4px var(--shadow-color);
}
.progress-bar {
  width: 7500px;
  height: 1000px;
  position: absolute;
  margin-bottom: 10px;
  top: 0;
  left: 0;
  z-index: 10;
}
.progress {
  height: 100%;
  background-color: rgba(0, 0, 0, 0.2);
  width: 0;
  z-index: 11;
}
.onsets-button {
  background-color: steelblue;
}
.timbre-button {
  background-color: rgba(50, 205, 50, 0.6);
}
.loudness-button {
  background-color: rgba(255, 215, 0, 0.6);
}
.chroma-button {
  background-color: rgba(255, 0, 255, 0.6);
}
.tempo-button {
  background-color: rgba(255, 69, 0, 0.6);
}
.spectral-centroid-button {
  background-color: rgba(0, 128, 128, 0.6);
}
.spectral-bandwidth-button {
  background-color: rgba(75, 0, 130, 0.6);
}
.zero-crossing-button {
  background-color: rgba(123, 104, 238, 0.6);
}
.spectral-contrast-button {
  background-color: rgba(255, 99, 71, 0.6);
}
.spectral-rolloff-button {
  background-color: rgba(255, 105, 180, 0.6);
}
.mel-spectrogram-button {
  background-color: rgba(0, 191, 255, 0.6);
}
.tonnetz-button {
  background-color: rgba(75, 0, 130, 0.6);
}
.harmonic-energy-button {
  background-color: rgba(34, 139, 34, 0.6);
}
.percussive-energy-button {
  background-color: rgba(255, 140, 0, 0.6);
}
.spectral-flux-button {
  background-color: rgba(46, 139, 87, 0.6);
}
.onset-strength-button {
  background-color: rgba(30, 144, 255, 0.6);
}
.pitch-button {
  background-color: rgba(0, 255, 127, 0.6);
}
.harmonic-ratio-button {
  background-color: rgba(139, 0, 139, 0.6);
}
.novelty-button {
  background-color: rgba(220, 20, 60, 0.6);
}
.spectral-centroid-velocity-button {
  background-color: rgba(0, 206, 209, 0.6);
}