/* roulang page: index */
:root {
      --primary: #E8451E;
      --primary-dark: #C0392B;
      --primary-light: rgba(232, 69, 30, 0.08);
      --secondary: #1E1E1E;
      --accent-brown: #8B5E3C;
      --accent-yellow: #F7B731;
      --bg: #FAF7F2;
      --white: #FFFFFF;
      --gray-light: #F5F0EB;
      --gray-border: #E0DCD7;
      --text: #2C2C2C;
      --text-weak: #6B625A;
      --radius-sm: 8px;
      --radius: 12px;
      --radius-lg: 16px;
      --shadow-sm: 0 4px 20px rgba(0,0,0,0.04);
      --shadow: 0 6px 24px rgba(0,0,0,0.06);
      --shadow-hover: 0 12px 32px rgba(0,0,0,0.1);
      --transition: 0.25s ease;
      --font-title: 'PingFang SC', 'Microsoft YaHei', 'Helvetica Neue', sans-serif;
      --font-body: 'PingFang SC', 'Microsoft YaHei', 'Helvetica Neue', sans-serif;
    }

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

    html {
      scroll-behavior: smooth;
      font-size: 16px;
    }

    body {
      font-family: var(--font-body);
      background-color: var(--bg);
      color: var(--text);
      line-height: 1.7;
      -webkit-font-smoothing: antialiased;
      -moz-osx-font-smoothing: grayscale;
    }

    img {
      max-width: 100%;
      height: auto;
      display: block;
    }

    a {
      color: inherit;
      text-decoration: none;
      transition: color var(--transition);
    }

    button, input, textarea {
      font-family: inherit;
      font-size: inherit;
    }

    .container {
      max-width: 1280px;
      margin-left: auto;
      margin-right: auto;
      padding-left: 1.5rem;
      padding-right: 1.5rem;
    }

    /* 导航玻璃态 */
    .header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      z-index: 50;
      transition: background var(--transition), box-shadow var(--transition), backdrop-filter var(--transition);
      background: rgba(250, 247, 242, 0.7);
      backdrop-filter: blur(12px);
      border-bottom: 1px solid rgba(255,255,255,0.25);
      box-shadow: 0 2px 12px rgba(0,0,0,0.04);
    }
    .header.scrolled {
      background: rgba(250, 247, 242, 0.95);
      backdrop-filter: blur(12px);
      box-shadow: 0 4px 20px rgba(0,0,0,0.08);
      border-bottom: 1px solid #E0DCD7;
    }

    .nav-link {
      position: relative;
      font-weight: 500;
      color: var(--secondary);
      padding: 0.4rem 0;
      transition: color var(--transition);
    }
    .nav-link::after {
      content: '';
      position: absolute;
      bottom: -2px;
      left: 0;
      width: 0%;
      height: 2px;
      background: var(--primary);
      transition: width var(--transition);
    }
    .nav-link:hover {
      color: var(--primary);
    }
    .nav-link:hover::after {
      width: 100%;
    }

    .btn-primary {
      background: var(--primary);
      color: white;
      border-radius: var(--radius-sm);
      padding: 0.7rem 1.8rem;
      font-weight: 600;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      transition: background var(--transition), transform 0.2s, box-shadow var(--transition);
      box-shadow: 0 4px 12px rgba(232,69,30,0.3);
      border: none;
      cursor: pointer;
    }
    .btn-primary:hover {
      background: var(--primary-dark);
      transform: scale(1.02);
      box-shadow: 0 6px 18px rgba(232,69,30,0.4);
    }

    .btn-outline {
      background: transparent;
      border: 2px solid var(--primary);
      color: var(--primary);
      border-radius: var(--radius-sm);
      padding: 0.65rem 1.7rem;
      font-weight: 600;
      transition: background var(--transition), color var(--transition), transform 0.2s;
    }
    .btn-outline:hover {
      background: var(--primary-light);
      transform: scale(1.02);
    }

    .section-title {
      font-family: var(--font-title);
      font-weight: 700;
      letter-spacing: -0.02em;
      color: var(--secondary);
    }

    .card {
      background: var(--white);
      border-radius: var(--radius);
      padding: 1.8rem;
      box-shadow: var(--shadow-sm);
      transition: box-shadow var(--transition), transform var(--transition);
      border: 1px solid rgba(0,0,0,0.03);
    }
    .card:hover {
      box-shadow: var(--shadow-hover);
      transform: translateY(-4px);
    }

    .stat-number {
      font-family: 'SF Pro Display', 'PingFang SC', sans-serif;
      font-weight: 700;
      color: var(--primary);
      line-height: 1.1;
    }

    .faq-item {
      border-bottom: 1px solid var(--gray-border);
    }
    .faq-question {
      width: 100%;
      background: none;
      border: none;
      text-align: left;
      padding: 1.2rem 0;
      font-weight: 600;
      display: flex;
      justify-content: space-between;
      align-items: center;
      cursor: pointer;
      color: var(--secondary);
      transition: color var(--transition);
    }
    .faq-question:hover {
      color: var(--primary);
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.35s ease;
      color: var(--text-weak);
    }
    .faq-item.open .faq-answer {
      max-height: 200px;
    }
    .faq-icon {
      color: var(--primary);
      font-size: 1.2rem;
      transition: transform 0.2s;
    }
    .faq-item.open .faq-icon {
      transform: rotate(45deg);
    }

    .input-field {
      width: 100%;
      background: var(--white);
      border: 1px solid var(--gray-border);
      border-radius: var(--radius-sm);
      padding: 0.8rem 1rem;
      transition: border-color var(--transition);
      outline: none;
    }
    .input-field:focus {
      border-color: var(--primary);
      box-shadow: 0 0 0 3px rgba(232,69,30,0.1);
    }

    footer {
      background: var(--secondary);
      color: #EAE5DF;
      border-top: 2px solid var(--primary);
    }

    @media (max-width: 768px) {
      .container {
        padding-left: 1.2rem;
        padding-right: 1.2rem;
      }
    }