/* roulang page: index */
:root {
      --color-turf-dark: #0B2B26;
      --color-turf-deep: #163832;
      --color-volt-active: #10B981;
      --color-volt-lime: #84CC16;
      --color-track-warn: #EA580C;
      --color-canvas-bg: #F8FAFC;
      --color-dark-panel: #061815;
      --font-stack: -apple-system, BlinkMacSystemFont, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
    }

    body {
      font-family: var(--font-stack);
      line-height: 1.78;
      color: #334155;
      background-color: #F8FAFC;
      overflow-x: hidden;
      margin: 0;
      padding: 0;
    }

    /* 锚点滚动距离防遮挡偏移 */
    section[id], div[id] {
      scroll-margin-top: 108px;
    }

    .theme-turf-bg { background-color: var(--color-turf-dark); }
    .theme-turf-deep { background-color: var(--color-turf-deep); }
    .theme-dark-panel { background-color: var(--color-dark-panel); }
    .theme-volt-text { color: var(--color-volt-active); }
    .theme-volt-bg { background-color: var(--color-volt-active); }
    
    .nav-blur-card {
      background: rgba(255, 255, 255, 0.94);
      backdrop-filter: blur(12px);
      -webkit-backdrop-filter: blur(12px);
    }

    .gradient-hero-mask {
      background: linear-gradient(135deg, rgba(11, 43, 38, 0.94) 0%, rgba(22, 56, 50, 0.88) 55%, rgba(6, 24, 21, 0.97) 100%);
    }

    .badge-volt {
      background: rgba(16, 185, 129, 0.15);
      border: 1px solid rgba(16, 185, 129, 0.4);
      color: #059669;
    }

    .btn-volt-action {
      background: linear-gradient(90deg, #10B981 0%, #059669 100%);
      transition: all 0.25s ease-in-out;
    }
    .btn-volt-action:hover {
      box-shadow: 0 10px 25px -5px rgba(16, 185, 129, 0.4);
      transform: translateY(-2px);
    }

    .btn-secondary-line {
      border: 1px solid rgba(255, 255, 255, 0.35);
      background: rgba(255, 255, 255, 0.08);
      color: #FFFFFF;
      transition: all 0.25s ease-in-out;
    }
    .btn-secondary-line:hover {
      border-color: #FFFFFF;
      background: rgba(255, 255, 255, 0.18);
      transform: translateY(-2px);
    }

    .glass-metric-card {
      background: rgba(255, 255, 255, 0.1);
      backdrop-filter: blur(10px);
      border: 1px solid rgba(255, 255, 255, 0.16);
    }

    .custom-card {
      transition: transform 0.3s cubic-bezier(0.16, 1, 0.3, 1), box-shadow 0.3s cubic-bezier(0.16, 1, 0.3, 1);
    }
    .custom-card:hover {
      transform: translateY(-4px);
      box-shadow: 0 20px 25px -5px rgba(15, 23, 42, 0.08), 0 8px 10px -6px rgba(15, 23, 42, 0.04);
    }

    /* 手风琴平滑过度 */
    .faq-content {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.35s ease-out, opacity 0.3s ease-out;
      opacity: 0;
    }
    .faq-item.active .faq-content {
      max-height: 280px;
      opacity: 1;
    }
    .faq-item.active .faq-chevron {
      transform: rotate(180deg);
    }

    /* 移动端菜单抽屉 */
    #mobile-drawer {
      transition: max-height 0.35s cubic-bezier(0.4, 0, 0.2, 1);
    }
    #mobile-drawer.open {
      max-height: 520px;
    }