:root {
  /* 字体 */
  --font-sans: 'Inter', 'Noto Sans SC', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --font-serif: 'Noto Serif SC', Georgia, 'Times New Roman', serif;
  --font-mono: 'Fira Code', 'SF Mono', Consolas, monospace;

  /* 颜色 - 浅色（Medium 暖白） */
  --color-bg: #ffffff;
  --color-bg-subtle: #fafafa;
  --color-bg-elevated: #ffffff;
  --color-surface: #ffffff;
  --color-surface-hover: #f7f7f7;

  --color-text: #242424;
  --color-text-soft: #6b6b6b;
  --color-text-faint: #8c8c8c;

  --color-border: #ececec;
  --color-border-strong: #e0e0e0;

  --color-accent: #1a8917;
  --color-accent-soft: #f2f7f2;
  --color-accent-hover: #156d12;

  --color-black: #242424;

  /* 字号 */
  --text-xs: 0.78rem;
  --text-sm: 0.875rem;
  --text-base: 1rem;
  --text-lg: 1.125rem;
  --text-xl: 1.375rem;
  --text-2xl: 1.75rem;
  --text-3xl: 2.25rem;
  --text-4xl: 3rem;

  /* 间距 */
  --space-1: 4px;
  --space-2: 8px;
  --space-3: 12px;
  --space-4: 16px;
  --space-5: 20px;
  --space-6: 24px;
  --space-8: 32px;
  --space-10: 40px;
  --space-12: 56px;
  --space-16: 80px;

  /* 圆角 */
  --radius-sm: 4px;
  --radius: 8px;
  --radius-lg: 14px;
  --radius-full: 999px;

  /* 阴影 */
  --shadow-sm: 0 1px 2px rgba(0,0,0,0.04);
  --shadow: 0 2px 8px rgba(0,0,0,0.06);
  --shadow-md: 0 4px 16px rgba(0,0,0,0.08);

  /* 布局 */
  --header-height: 64px;
  --content-width: 720px;
  --reading-width: 680px;

  --transition: 0.2s cubic-bezier(0.4, 0, 0.2, 1);
  --transition-slow: 0.35s cubic-bezier(0.4, 0, 0.2, 1);
}

[data-theme="dark"] {
  --color-bg: #0f0f0f;
  --color-bg-subtle: #161616;
  --color-bg-elevated: #1a1a1a;
  --color-surface: #1a1a1a;
  --color-surface-hover: #232323;

  --color-text: #e8e8e8;
  --color-text-soft: #a8a8a8;
  --color-text-faint: #777777;

  --color-border: #2a2a2a;
  --color-border-strong: #383838;

  --color-accent: #4caf50;
  --color-accent-soft: #1c261c;
  --color-accent-hover: #66bb6a;

  --color-black: #e8e8e8;
}