:root {
  /* 颜色 */
  --bg-primary: #0a0a12;
  --bg-secondary: #12121e;
  --bg-card: #1a1a2e;
  --text-primary: #e8e8f0;
  --text-secondary: #8888aa;
  --accent-gold: #FFD700;
  --accent-blue: #4A9EFF;
  --accent-red: #FF4444;
  --accent-green: #44FF88;
  --note-click: #4A9EFF;
  --note-hold: #4A9EFF;
  --note-drag: #FFB800;

  /* 字体 */
  --font-main: 'Inter', 'Noto Sans SC', -apple-system, BlinkMacSystemFont, sans-serif;
  --font-mono: 'JetBrains Mono', 'Fira Code', monospace;

  /* 尺寸 */
  --radius: 8px;
  --radius-lg: 12px;
}

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html, body {
  width: 100%;
  height: 100%;
  overflow: hidden;
  font-family: var(--font-main);
  background: var(--bg-primary);
  color: var(--text-primary);
  -webkit-font-smoothing: antialiased;
  user-select: none;
  -webkit-user-select: none;
}

#app {
  width: 100%;
  height: 100%;
  position: relative;
}

/* 通用按钮 */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 12px 32px;
  border: none;
  border-radius: var(--radius);
  font-family: var(--font-main);
  font-size: 16px;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.2s ease;
  color: var(--text-primary);
  background: var(--bg-card);
}

.btn:hover {
  background: #2a2a44;
  transform: translateY(-1px);
}

.btn:active {
  transform: translateY(0);
}

.btn-primary {
  background: var(--accent-blue);
  color: #fff;
}

.btn-primary:hover {
  background: #3a8eef;
}

.btn-gold {
  background: var(--accent-gold);
  color: #000;
}

.btn-gold:hover {
  background: #eec600;
}

/* 屏幕切换动画 */
.screen {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  opacity: 0;
  transition: opacity 0.3s ease;
  pointer-events: none;
}

.screen.active {
  opacity: 1;
  pointer-events: auto;
}

/* 滚动条 */
::-webkit-scrollbar {
  width: 6px;
}

::-webkit-scrollbar-track {
  background: var(--bg-secondary);
}

::-webkit-scrollbar-thumb {
  background: var(--text-secondary);
  border-radius: 3px;
}

::-webkit-scrollbar-thumb:hover {
  background: #aaa;
}

/* 隐藏 */
.hidden {
  display: none !important;
}