body {
  margin: 0;
  padding: 0;
  font-family: Arial, sans-serif;
  background: rgb(255, 128, 0);
  min-height: 100vh;
  overflow: hidden;
}

.scene {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-direction: column;
}

.hidden {
  display: none !important;
}

/* スタートシーンのスタイル */
.content {
  text-align: center;
  color: white;
  padding: 20px;
}

.content h1 {
  margin: 0 0 20px 0;
  font-size: 2.5em;
  text-shadow: 0 2px 4px rgba(0, 0, 0, 0.3);
}

.content p {
  margin: 0 0 30px 0;
  font-size: 1.1em;
  opacity: 0.9;
  max-width: 400px;
  line-height: 1.5;
}

.start-button {
  padding: 15px 40px;
  font-size: 1.2em;
  background: #fff;
  color: #667eea;
  border: none;
  border-radius: 8px;
  cursor: pointer;
  box-shadow: 0 4px 15px rgba(0, 0, 0, 0.2);
  transition: all 0.3s ease;
}

.start-button:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(0, 0, 0, 0.3);
}

/* キャンバスシーンのスタイル */
#canvas {
  border: 2px solid rgba(255, 255, 255, 0.3);
  border-radius: 10px;
  background: rgba(255, 255, 255, 0.1);
  backdrop-filter: blur(10px);
}

.back-button {
  position: absolute;
  top: 20px;
  left: 20px;
  padding: 10px 20px;
  background: rgba(255, 255, 255, 0.2);
  color: white;
  border: 1px solid rgba(255, 255, 255, 0.3);
  border-radius: 8px;
  cursor: pointer;
  font-size: 14px;
  transition: all 0.3s ease;
}

.back-button:hover {
  background: rgba(255, 255, 255, 0.3);
}

.error {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  background: rgba(255, 0, 0, 0.8);
  color: white;
  padding: 20px;
  border-radius: 8px;
  text-align: center;
  font-size: 1.1em;
  box-shadow: 0 4px 15px rgba(0, 0, 0, 0.3);
}