/* roulang page: index */
:root {
      --primary: #0E8388;
      --primary-hover: #0a6c70;
      --secondary: #2E4F4F;
      --accent: #FF9F45;
      --bg-base: #F8FBFB;
      --bg-card: #FFFFFF;
      --dark-accent: #1A2C2C;
      --text-main: #1E293B;
      --text-muted: #475569;
      --text-light: #64748B;
      --border-color: #E2E8F0;
    }

    html {
      scroll-behavior: smooth;
      font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
    }

    body {
      background-color: var(--bg-base);
      color: var(--text-main);
      line-height: 1.8;
      margin: 0;
      padding: 0;
    }

    section {
      scroll-margin-top: 80px;
    }

    .brand-glow {
      text-shadow: 0 0 20px rgba(14, 131, 136, 0.25);
    }

    .card-shadow {
      box-shadow: 0 4px 20px -2px rgba(14, 131, 136, 0.08);
      transition: all 0.25s cubic-bezier(0.4, 0, 0.2, 1);
    }
    .card-shadow:hover {
      box-shadow: 0 12px 30px -4px rgba(14, 131, 136, 0.16);
      transform: translateY(-4px);
    }

    .btn-gradient {
      background-color: var(--primary);
      transition: background-color 0.2s ease, transform 0.15s ease;
    }
    .btn-gradient:hover {
      background-color: var(--primary-hover);
      transform: translateY(-1px);
    }

    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s cubic-bezier(0, 1, 0, 1);
    }
    .faq-item.active .faq-answer {
      max-height: 280px;
      transition: max-height 0.3s cubic-bezier(1, 0, 1, 0);
    }
    .faq-item.active .faq-arrow {
      transform: rotate(180deg);
    }