/* roulang page: index */
:root {
      --brand-navy: #0A2540;
      --brand-dark: #0D1B2A;
      --brand-blue: #0052FF;
      --brand-teal: #00D4B2;
      --brand-accent: #FF6B35;
      --bg-light: #F8FAFC;
      --card-border: rgba(10, 37, 64, 0.08);
      --shadow-default: 0 4px 20px -2px rgba(10, 37, 64, 0.06);
      --shadow-hover: 0 20px 30px -4px rgba(0, 82, 255, 0.14);
    }

    * {
      box-sizing: border-box;
      scroll-behavior: smooth;
    }

    body {
      font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "PingFang SC", "Microsoft YaHei", sans-serif;
      color: #1E293B;
      background-color: #FFFFFF;
      overflow-x: hidden;
      line-height: 1.6;
    }

    .brand-gradient-text {
      background: linear-gradient(135deg, #0052FF 0%, #00D4B2 100%);
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
    }

    .brand-gradient-btn {
      background: linear-gradient(135deg, #0052FF 0%, #00D4B2 100%);
      transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    }
    .brand-gradient-btn:hover {
      box-shadow: 0 10px 25px -5px rgba(0, 82, 255, 0.4);
      transform: translateY(-2px);
    }
    .brand-gradient-btn:active {
      transform: translateY(0);
    }

    .card-modern {
      background: #FFFFFF;
      border: 1px solid var(--card-border);
      border-radius: 20px;
      box-shadow: var(--shadow-default);
      transition: all 0.3s ease;
    }
    .card-modern:hover {
      box-shadow: var(--shadow-hover);
      transform: translateY(-4px);
      border-color: rgba(0, 82, 255, 0.25);
    }

    .data-badge-glow {
      background: rgba(0, 212, 178, 0.12);
      border: 1px solid rgba(0, 212, 178, 0.3);
      color: #008775;
    }

    .section-spacing {
      padding-top: 5.5rem;
      padding-bottom: 5.5rem;
    }

    /* 手风琴动效 */
    .faq-content {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.35s cubic-bezier(0, 1, 0, 1);
    }
    .faq-item.active .faq-content {
      max-height: 500px;
      transition: max-height 0.45s ease-in-out;
    }
    .faq-item.active .faq-icon {
      transform: rotate(180deg);
    }

    /* 移动抽屉遮罩 */
    #mobileMenu {
      transition: transform 0.3s ease-in-out, opacity 0.3s ease-in-out;
    }
    #mobileMenu.hidden-menu {
      transform: translateX(100%);
      opacity: 0;
      pointer-events: none;
    }
    #mobileMenu.show-menu {
      transform: translateX(0);
      opacity: 1;
      pointer-events: auto;
    }