/* roulang page: index */
:root {
      --primary: #1A5FDC;
      --primary-dark: #1550C0;
      --accent: #00C2E0;
      --bg-light: #F4F7FC;
      --bg-white: #FFFFFF;
      --text-main: #1E293B;
      --text-soft: #64748B;
      --text-light: #94A3B8;
      --border-light: #E8ECF2;
      --border-input: #D1D9E6;
      --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.04);
      --shadow-md: 0 8px 24px rgba(26, 95, 220, 0.12);
      --radius-card: 12px;
      --radius-btn: 8px;
      --radius-chip: 20px;
      --font-sans: "Inter", "SF Pro Display", -apple-system, "PingFang SC", "Microsoft YaHei", sans-serif;
      --transition-smooth: 0.25s ease;
    }

    * {
      box-sizing: border-box;
      margin: 0;
      padding: 0;
    }

    body {
      font-family: var(--font-sans);
      background-color: var(--bg-white);
      color: var(--text-main);
      line-height: 1.7;
      -webkit-font-smoothing: antialiased;
      scroll-behavior: smooth;
    }

    .container {
      max-width: 1280px;
      margin: 0 auto;
      padding: 0 2rem;
    }

    @media (max-width: 768px) {
      .container {
        padding: 0 1.25rem;
      }
    }

    /* 导航栏毛玻璃效果 */
    .nav-glass {
      background: rgba(255, 255, 255, 0.88);
      backdrop-filter: blur(12px);
      -webkit-backdrop-filter: blur(12px);
      border-bottom: 1px solid rgba(232, 236, 242, 0.7);
      box-shadow: 0 2px 12px rgba(0,0,0,0.02);
    }

    /* 分段标签chip */
    .nav-chip {
      display: inline-flex;
      align-items: center;
      padding: 0.4rem 1rem;
      border-radius: var(--radius-chip);
      font-size: 0.9rem;
      font-weight: 500;
      color: var(--text-soft);
      background: transparent;
      transition: background 0.2s, color 0.2s;
      white-space: nowrap;
    }
    .nav-chip:hover {
      background: #EDF2FA;
      color: var(--primary);
    }
    .nav-chip.active {
      background: var(--primary);
      color: white;
      font-weight: 600;
    }

    /* 卡片系统 */
    .card {
      background: var(--bg-white);
      border: 1px solid var(--border-light);
      border-radius: var(--radius-card);
      box-shadow: var(--shadow-sm);
      transition: transform var(--transition-smooth), box-shadow var(--transition-smooth);
      overflow: hidden;
    }
    .card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-md);
    }

    /* 按钮 */
    .btn-primary {
      background-color: var(--primary);
      color: white;
      border-radius: var(--radius-btn);
      padding: 0.75rem 1.75rem;
      font-weight: 600;
      font-size: 1rem;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      border: none;
      cursor: pointer;
      transition: background 0.2s, box-shadow 0.2s;
      text-decoration: none;
      box-shadow: 0 4px 10px rgba(26,95,220,0.25);
    }
    .btn-primary:hover {
      background-color: var(--primary-dark);
      box-shadow: 0 6px 16px rgba(26,95,220,0.35);
    }
    .btn-secondary {
      background: transparent;
      border: 1.5px solid var(--primary);
      color: var(--primary);
      border-radius: var(--radius-btn);
      padding: 0.7rem 1.7rem;
      font-weight: 600;
      font-size: 1rem;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      transition: background 0.2s, color 0.2s;
      text-decoration: none;
    }
    .btn-secondary:hover {
      background: rgba(26,95,220,0.08);
    }
    .btn-accent {
      background: var(--accent);
      color: #fff;
      border-radius: var(--radius-btn);
      padding: 0.65rem 1.5rem;
      font-weight: 600;
      font-size: 0.95rem;
      box-shadow: 0 4px 10px rgba(0,194,224,0.3);
      border: none;
      cursor: pointer;
      transition: background 0.2s;
    }
    .btn-accent:hover {
      background: #00A8C4;
    }

    /* 统计数字 */
    .stat-number {
      font-size: 3rem;
      font-weight: 800;
      color: var(--primary);
      line-height: 1.2;
      letter-spacing: -0.02em;
    }
    @media (max-width: 768px) {
      .stat-number {
        font-size: 2.2rem;
      }
    }

    /* FAQ 手风琴 */
    .faq-item {
      border-bottom: 1px solid var(--border-light);
      padding: 1.25rem 0;
    }
    .faq-question {
      display: flex;
      align-items: center;
      cursor: pointer;
      font-weight: 600;
      font-size: 1.15rem;
      color: var(--text-main);
      gap: 0.6rem;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.35s ease, padding 0.2s;
      background: #F4F7FC;
      border-radius: 8px;
      margin-top: 0.5rem;
      padding: 0 1rem;
      color: var(--text-soft);
      line-height: 1.6;
    }
    .faq-item.active .faq-answer {
      max-height: 200px;
      padding: 1rem;
    }
    .faq-icon {
      color: var(--accent);
      font-size: 1.3rem;
    }

    /* 表单 */
    .input-field {
      width: 100%;
      padding: 0.8rem 1rem;
      border: 1px solid var(--border-input);
      border-radius: var(--radius-btn);
      font-family: var(--font-sans);
      transition: border 0.2s, box-shadow 0.2s;
      background: white;
      font-size: 0.95rem;
    }
    .input-field:focus {
      outline: none;
      border-color: var(--primary);
      box-shadow: 0 0 0 3px rgba(26,95,220,0.15);
    }

    footer {
      background: #1E293B;
      color: #CBD5E1;
      padding: 3rem 0 1.5rem;
    }
    footer a {
      color: #CBD5E1;
      text-decoration: none;
      transition: color 0.2s;
    }
    footer a:hover {
      color: white;
    }
    .footer-logo {
      filter: brightness(0) invert(1);
    }