:root {
  /* 品牌核心色彩体系：探索者大地与天际色调 */
  --color-brand-dark: #0f172a;
  --color-brand-primary: #1e3a8a;
  --color-brand-accent: #2563eb;
  --color-brand-warm: #d97706;
  --color-brand-terracotta: #dc2626;
  --color-brand-emerald: #059669;
  
  /* 中性背景与文字阶梯 */
  --bg-main: #f8fafc;
  --bg-card: #ffffff;
  --bg-card-subtle: #f1f5f9;
  --bg-hero: linear-gradient(135deg, #0f172a 0%, #1e293b 50%, #172554 100%);
  
  --text-primary: #0f172a;
  --text-secondary: #475569;
  --text-muted: #64748b;
  --text-inverse: #f8fafc;
  --text-inverse-muted: #94a3b8;
  
  /* 边框与分割线 */
  --border-subtle: #e2e8f0;
  --border-focus: #3b82f6;
  
  /* 阴影层次 */
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.08), 0 2px 4px -2px rgba(0, 0, 0, 0.04);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.08), 0 4px 6px -4px rgba(0, 0, 0, 0.03);
  --shadow-hover: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 8px 10px -6px rgba(0, 0, 0, 0.04);
  
  /* 圆角规范 */
  --radius-sm: 6px;
  --radius-md: 12px;
  --radius-lg: 18px;
  --radius-full: 9999px;
  
  /* 动效过渡时间 */
  --transition-fast: 0.15s ease;
  --transition-normal: 0.25s cubic-bezier(0.16, 1, 0.3, 1);
}