/* CSS 变量定义 - 统一设计系统 */
:root {
  /* ========================================
     主色系 - Primary Colors
     ======================================== */
  --color-primary: #667eea;
  --color-secondary: #764ba2;

  /* 主色透明度变体 */
  --color-primary-05: rgba(102, 126, 234, 0.05);
  --color-primary-08: rgba(102, 126, 234, 0.08);
  --color-primary-10: rgba(102, 126, 234, 0.1);
  --color-primary-12: rgba(102, 126, 234, 0.12);
  --color-primary-15: rgba(102, 126, 234, 0.15);
  --color-primary-18: rgba(102, 126, 234, 0.18);
  --color-primary-20: rgba(102, 126, 234, 0.2);
  --color-primary-30: rgba(102, 126, 234, 0.3);
  --color-primary-40: rgba(102, 126, 234, 0.4);
  --color-primary-50: rgba(102, 126, 234, 0.5);
  --color-primary-60: rgba(102, 126, 234, 0.6);

  /* 次色透明度变体 */
  --color-secondary-05: rgba(118, 75, 162, 0.05);
  --color-secondary-15: rgba(118, 75, 162, 0.15);
  --color-secondary-80: rgba(118, 75, 162, 0.8);

  /* ========================================
     渐变色 - Gradients
     ======================================== */
  --gradient-primary: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  --gradient-primary-reverse: linear-gradient(135deg, #764ba2 0%, #667eea 100%);
  --gradient-primary-light: linear-gradient(135deg, rgba(102, 126, 234, 0.05) 0%, rgba(118, 75, 162, 0.05) 100%);
  --gradient-primary-15: linear-gradient(135deg, rgba(102, 126, 234, 0.15) 0%, rgba(118, 75, 162, 0.15) 100%);
  --gradient-primary-vertical: linear-gradient(180deg, #667eea 0%, rgba(102, 126, 234, 0.8) 100%);
  --gradient-secondary-vertical: linear-gradient(180deg, #764ba2 0%, rgba(118, 75, 162, 0.8) 100%);
  --gradient-bg: linear-gradient(135deg, #f5f7fa 0%, #e4e8f0 100%);

  /* ========================================
     中性色 - Neutral Colors
     ======================================== */
  /* 白色系 */
  --color-white: #ffffff;
  --color-white-30: rgba(255, 255, 255, 0.3);
  --color-white-40: rgba(255, 255, 255, 0.4);
  --color-white-65: rgba(255, 255, 255, 0.65);
  --color-white-70: rgba(255, 255, 255, 0.7);
  --color-white-75: rgba(255, 255, 255, 0.75);
  --color-white-80: rgba(255, 255, 255, 0.8);
  --color-white-85: rgba(255, 255, 255, 0.85);
  --color-white-90: rgba(255, 255, 255, 0.9);
  --color-white-95: rgba(255, 255, 255, 0.95);
  --color-white-98: rgba(255, 255, 255, 0.98);

  /* 浅色背景 */
  --color-light: #f8f9fc;
  --color-light-50: rgba(248, 249, 252, 0.5);
  --color-light-60: rgba(248, 249, 252, 0.6);
  --color-light-80: rgba(248, 249, 252, 0.8);
  --color-light-90: rgba(248, 249, 252, 0.9);

  --color-light-blue: #f1f5f9;
  --color-light-blue-50: rgba(241, 245, 249, 0.5);
  --color-light-blue-80: rgba(241, 245, 249, 0.8);

  /* ========================================
     文本色 - Text Colors
     ======================================== */
  --color-text-dark: #2d3748;
  --color-text-primary: #1e293b;
  --color-text-medium: #475569;
  --color-text-gray: #64748b;
  --color-text-light: #94a3b8;
  --color-text-muted: #666;
  --color-text-nav: #333;

  /* ========================================
     边框色 - Border Colors
     ======================================== */
  --color-border: #e2e8f0;
  --color-border-light: #e1e4e8;
  --color-border-lighter: rgba(226, 232, 240, 0.3);

  /* ========================================
     链接色 - Link Colors
     ======================================== */
  --color-link: #0366d6;
  --color-error: #ef4444;
  --color-accent-red: #f43f5e;

  /* ========================================
     覆盖色 - Overlay Colors
     ======================================== */
  --color-overlay: rgba(0, 0, 0, 0.5);
  --color-overlay-light: rgba(0, 0, 0, 0.15);
  --color-overlay-dark: rgba(0, 0, 0, 0.3);

  /* ========================================
     阴影系统 - Shadows
     ======================================== */
  --shadow-xs: 0 1px 3px rgba(0, 0, 0, 0.08);
  --shadow-sm: 0 2px 4px rgba(0, 0, 0, 0.1);
  --shadow-card: 0 4px 16px var(--color-primary-08);
  --shadow-card-hover: 0 8px 24px var(--color-primary-12);
  --shadow-md: 0 8px 32px var(--color-primary-10);
  --shadow-lg: 0 12px 40px var(--color-primary-15);
  --shadow-xl: 0 12px 40px var(--color-primary-18);
  --shadow-focus: 0 6px 25px var(--color-primary-50);
  --shadow-btn: 0 2px 8px var(--color-primary-20);
  --shadow-btn-hover: 0 4px 12px var(--color-primary-30);
  --shadow-inset: inset 0 2px 8px var(--color-primary-10);
  --shadow-top: 0 -4px 20px var(--color-overlay-light);

  /* ========================================
     圆角系统 - Border Radius
     ======================================== */
  --radius-xs: 2px;
  --radius-sm: 6px;
  --radius-base: 8px;
  --radius-md: 10px;
  --radius-lg: 12px;
  --radius-xl: 16px;
  --radius-2xl: 20px;
  --radius-3xl: 24px;
  --radius-full: 50%;

  /* ========================================
     过渡系统 - Transitions
     ======================================== */
  --transition-fast: all 0.2s ease;
  --transition-normal: all 0.3s ease;
  --transition-smooth: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  --transition-slow: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
  --transition-color: color 0.3s ease;
  --transition-transform: transform 0.3s ease;
  --transition-expand: max-height 0.4s cubic-bezier(0.4, 0, 0.2, 1);

  /* ========================================
     模糊效果 - Blur Effects
     ======================================== */
  --blur-sm: blur(10px);
  --blur-md: blur(15px);
  --blur-lg: blur(20px);

  /* ========================================
     布局系统 - Layout
     ======================================== */
  --container-max-width: 1000px;
  --container-max-width-lg: 1400px;
  --container-padding: 20px;
  --container-padding-tablet: 15px;
  --container-padding-mobile: 8px;

  --gap-xs: 6px;
  --gap-sm: 10px;
  --gap-md: 16px;
  --gap-lg: 20px;
  --gap-xl: 30px;

  /* ========================================
     Z-index 层级
     ======================================== */
  --z-sticky: 100;
  --z-header: 1000;
  --z-floating: 1000;
  --z-overlay: 9998;
  --z-modal: 9999;

  /* ========================================
     字体系统 - Typography
     ======================================== */
  --font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --font-mono: "Consolas", "Monaco", "Courier New", monospace;
  --line-height: 1.6;
  --line-height-tight: 1.3;
  --line-height-relaxed: 1.8;
}