/* ================= 设计变量与基础重置 (Variables & Reset) ================= */
  :root {
    --sidebar-width: 236px;
    --sidebar-width-collapsed: 72px;
    
    --bg-page: #0f1115;
    --bg-surface: #16181d;
    --bg-surface-hover: #1f2229;
    --bg-surface-active: #242831;
    --bg-card: #16181d;
    --bg-card-hover: #1a1d24;
    --bg-glass: rgba(22, 24, 29, 0.88);
    
    --border: rgba(255, 255, 255, 0.06);
    --border-subtle: rgba(255, 255, 255, 0.035);
    --border-hover: rgba(255, 255, 255, 0.16);
    
    --text-primary: #f3f4f6;
    --text-secondary: #9ca3af;
    --text-muted: #6b7280;
    
    /* Momoyu Pro 薄荷青绿与金橙 */
    --accent: #2dd4bf;
    --accent-hover: #14b8a6;
    --accent-soft: rgba(45, 212, 191, 0.12);
    --accent-glow: rgba(45, 212, 191, 0.25);
    --accent-dark: #0f766e;
    
    --rank-gold: #f97316;
    --card-shadow: 0 4px 20px -2px rgba(0, 0, 0, 0.5), 0 2px 6px -1px rgba(0, 0, 0, 0.4);
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 16px;
    --radius-pill: 9999px;
    
    --grid-cols: 4;
  }

  body.light {
    --bg-page: #F5F5F7;
    --bg-surface: #ffffff;
    --bg-surface-hover: #f3f4f6;
    --bg-surface-active: #e5e7eb;
    --bg-card: #ffffff;
    --bg-card-hover: #f8fafc;
    --bg-glass: rgba(255, 255, 255, 0.92);
    
    --border: #e2e8f0;
    --border-subtle: #f1f5f9;
    --border-hover: #cbd5e1;
    
    --text-primary: #0f172a;
    --text-secondary: #475569;
    --text-muted: #94a3b8;
    
    --accent: #0d9488;
    --accent-hover: #0f766e;
    --accent-soft: rgba(13, 148, 136, 0.1);
    --accent-glow: rgba(13, 148, 136, 0.2);
    
    --rank-gold: #ea580c;
    --card-shadow: 0 2px 10px rgba(0, 0, 0, 0.04), 0 10px 24px -4px rgba(0, 0, 0, 0.06);
  }

  * { box-sizing: border-box; margin: 0; padding: 0; -webkit-tap-highlight-color: transparent; }
  
  html, body {
    min-height: 100%;
    height: 100%;
  }

  /* Momoyu Pro 标志性暗夜网格纹理 */
  body {
    background-color: var(--bg-page);
    background-image: linear-gradient(90deg, rgba(255, 255, 255, 0.035) 1px, transparent 1px),
                      linear-gradient(rgba(255, 255, 255, 0.035) 1px, transparent 1px);
    background-size: 32px 32px;
    color: var(--text-primary);
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "PingFang SC", "Microsoft YaHei", sans-serif;
    font-size: 14px;
    line-height: 1.5;
    transition: background-color .25s ease, color .25s ease;
    overflow-x: hidden;
  }

  body.light {
    background-image: linear-gradient(90deg, rgba(0, 0, 0, 0.035) 1px, transparent 1px),
                      linear-gradient(rgba(0, 0, 0, 0.035) 1px, transparent 1px);
  }

  a { color: inherit; text-decoration: none; }
  button { font-family: inherit; }

  /* ================= 整体两栏布局 (Sidebar + Main) ================= */