body {
  font-family: sans-serif;
  margin: 0;
  padding: 20px;
  text-align: center;
}

h1 {
  margin-bottom: 20px;
}

.main-container {
  display: flex;
  justify-content: center;
  align-items: flex-start;
  gap: 20px;
}

.tutorial {
  width: 150px;
  text-align: center;
  font-size: 14px;
  color: #333;
}

.tutorial-left {
  text-align: right;
}

.tutorial-right {
  text-align: left;
}

.container {
  display: flex;
  flex-direction: column;
  align-items: center;
}

canvas {
  width: 640px;
  height: auto;
  border: 2px solid #333;
  display: block;
  margin: 0 auto 20px auto;
}

.tracks {
  display: flex;
  justify-content: center;
  gap: 10px;
  margin-top: 20px;
}

.sound-control {
  display: flex;
  justify-content: center;
  gap: 15px;
  margin-bottom: 20px;
}

.track {
  padding: 10px 20px;
  background-color: #eee;
  border: 2px solid #ccc;
  border-radius: 8px;
  transition: background-color 0.3s ease;
  min-width: 100px;
  text-align: center;
}

.track.active {
  background-color: #90ee90;
  border-color: #2ecc71;
}

.volume-bar-container {
  width: 100px;
  height: 10px;
  background-color: #eee;
  margin: 5px auto;
}

.volume-bar {
  height: 100%;
  background-color: #4caf50;
  width: 0%;
  transition: width 0.2s ease;
}