/* ============================================================
   双主题 CSS 变量
   通过 <html data-theme="dark|light"> 切换，全站统一管理
   ============================================================ */

:root,
[data-theme="dark"] {
  --color-bg:            #0d1117;
  --color-bg-card:       #161b22;
  --color-bg-hover:      #1f242c;
  --color-bg-sidebar:    #0d1117;
  --color-bg-toc:        transparent;
  --color-border:        #30363d;
  --color-border-soft:   #21262d;
  --color-text:          #c9d1d9;
  --color-text-muted:    #8b949e;
  --color-primary:       #58a6ff;
  --color-accent:        #79c0ff;
  --color-primary-bg:    rgba(56, 139, 253, 0.12);
  --color-primary-border:rgba(56, 139, 253, 0.4);
  --color-code-bg:       #161b22;
  --color-code-inline-bg:rgba(110, 118, 129, 0.2);
  --color-success:       #3fb950;
  --color-danger:        #f85149;
  --shadow-soft:         0 1px 3px rgba(0, 0, 0, 0.3);
  --shadow-elevated:     0 8px 24px rgba(0, 0, 0, 0.45);
}

[data-theme="light"] {
  --color-bg:            #ffffff;
  --color-bg-card:       #f6f8fa;
  --color-bg-hover:      #eaeef2;
  --color-bg-sidebar:    #ffffff;
  --color-bg-toc:        transparent;
  --color-border:        #d0d7de;
  --color-border-soft:   #eaeef2;
  --color-text:          #1f2328;
  --color-text-muted:    #656d76;
  --color-primary:       #0969da;
  --color-accent:        #0598ff;
  --color-primary-bg:    rgba(9, 105, 218, 0.08);
  --color-primary-border:rgba(9, 105, 218, 0.35);
  --color-code-bg:       #f6f8fa;
  --color-code-inline-bg:rgba(175, 184, 193, 0.2);
  --color-success:       #1a7f37;
  --color-danger:        #cf222e;
  --shadow-soft:         0 1px 3px rgba(31, 35, 40, 0.12);
  --shadow-elevated:     0 8px 24px rgba(31, 35, 40, 0.12);
}

/* 布局 / 排版尺寸变量（主题无关） */
:root {
  --sidebar-width:     280px;
  --toc-width:         240px;
  --content-max-width: 820px;
  --header-height:     56px;

  --font-sans: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC',
               'Hiragino Sans GB', 'Microsoft YaHei', Helvetica, Arial, sans-serif;
  --font-mono: 'SF Mono', 'Fira Code', 'Cascadia Code', Consolas,
               'Liberation Mono', Menlo, monospace;

  --radius-sm: 4px;
  --radius-md: 8px;
  --radius-lg: 12px;

  --transition-fast:   150ms ease;
  --transition-normal: 250ms ease;
}

/* 主题切换全局平滑过渡 */
html {
  transition: background-color var(--transition-normal),
              color var(--transition-normal);
}