:root {
  --base-width: 400px;
  --base-height: auto;
}

body {
  margin: 0;
  overflow: hidden;
  background-color: #000;
  height: 100vh;
  font-family: Arial, sans-serif;
}

#dvd-logo {
  position: fixed;
  top: 0;
  left: 0;
  user-select: none;
  will-change: transform;
}

#logo-img {
  width: var(--base-width);
  height: var(--base-height);
  transform-origin: center;
  transition: transform 0.3s ease;
  will-change: transform, filter;
}

#corner-message {
  position: fixed;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  color: #fff;
  font-size: 48px;
  font-weight: bold;
  text-align: center;
  z-index: 2000;
  opacity: 0;
  transition: opacity 0.3s ease;
}

#corner-message.visible {
  opacity: 1;
  animation: message-fade 3s forwards;
}

#controls {
  position: fixed;
  bottom: 20px;
  right: 20px;
  color: rgba(255, 255, 255, 0.7);
  background-color: rgba(0, 0, 0, 0.8);
  padding: 15px;
  border-radius: 8px;
  font-size: 14px;
  z-index: 1000;
  max-width: 300px;
  transition: opacity 0.3s ease;
}

.controls-hidden #controls {
  opacity: 0;
  pointer-events: none;
}

#settings-panel {
  margin-bottom: 15px;
  display: none;
}

#settings-panel.visible {
  display: block;
}

#settings-panel h3 {
  margin: 0 0 15px 0;
  font-size: 16px;
  color: #fff;
}

.setting-group {
  margin-bottom: 12px;
}

.setting-group label {
  display: block;
  margin-bottom: 5px;
  color: #fff;
}

.setting-group input[type="text"] {
  width: 100%;
  padding: 5px;
  border: none;
  border-radius: 4px;
  background: rgba(255, 255, 255, 0.1);
  color: #fff;
}

.setting-group input[type="range"] {
  width: 100%;
  margin: 5px 0;
}

button {
  background: rgba(255, 255, 255, 0.1);
  border: 1px solid rgba(255, 255, 255, 0.3);
  color: #fff;
  padding: 8px 12px;
  border-radius: 4px;
  cursor: pointer;
  margin-right: 8px;
  margin-bottom: 8px;
  transition: background-color 0.2s ease;
}

button:hover {
  background: rgba(255, 255, 255, 0.2);
}

#instructions {
  white-space: pre-line;
  line-height: 1.5;
  padding-top: 10px;
  border-top: 1px solid rgba(255, 255, 255, 0.1);
}

/* アニメーション */
@keyframes rainbow {
  0% { filter: hue-rotate(0deg); }
  100% { filter: hue-rotate(360deg); }
}

@keyframes message-fade {
  0% { opacity: 0; transform: translate(-50%, -50%) scale(0.8); }
  10% { opacity: 1; transform: translate(-50%, -50%) scale(1); }
  80% { opacity: 1; transform: translate(-50%, -50%) scale(1); }
  100% { opacity: 0; transform: translate(-50%, -50%) scale(0.8); }
}

.rainbow-effect {
  animation: rainbow 3s linear infinite;
}

/* レスポンシブ対応 */
@media (max-width: 768px) {
  :root {
    --base-width: 200px;
  }
  
  #corner-message {
    font-size: 32px;
  }
  
  #controls {
    max-width: 250px;
    font-size: 12px;
  }
}