/* roulang page: index */
/* 设计变量与全局重置 */
    :root {
      --primary: #FF6B4A;
      --primary-dark: #E85D3A;
      --primary-soft: rgba(255, 107, 74, 0.10);
      --primary-15: rgba(255, 107, 74, 0.15);
      --secondary-dark: #1E1E2C;
      --secondary-light: #F7F5F2;
      --accent: #00C4B4;
      --accent-soft: rgba(0, 196, 180, 0.08);
      --text-main: #1E1E2C;
      --text-secondary: #4B5563;
      --text-muted: #6B7280;
      --border-light: #E8E6E1;
      --card-bg: #FFFFFF;
      --shadow-sm: 0 2px 8px rgba(0,0,0,0.06);
      --shadow-md: 0 8px 24px rgba(0,0,0,0.10);
      --shadow-lg: 0 16px 32px rgba(0,0,0,0.12);
      --radius-card: 12px;
      --radius-btn: 8px;
      --radius-chip: 20px;
      --font-sans: "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", system-ui, -apple-system, sans-serif;
      --transition-smooth: all 0.25s ease;
    }

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

    body {
      font-family: var(--font-sans);
      background-color: #FFFFFF;
      color: var(--text-main);
      line-height: 1.75;
      -webkit-font-smoothing: antialiased;
    }

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

    a {
      text-decoration: none;
      color: inherit;
    }

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

    .container {
      max-width: 1200px;
      margin: 0 auto;
      padding-left: 20px;
      padding-right: 20px;
    }

    /* 导航栏 */
    .navbar {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 72px;
      background: rgba(247, 245, 242, 0.85);
      backdrop-filter: blur(12px);
      border-bottom: 1px solid var(--border-light);
      z-index: 50;
      display: flex;
      align-items: center;
      transition: var(--transition-smooth);
    }

    .navbar.scrolled {
      background: rgba(247, 245, 242, 1);
      box-shadow: 0 2px 12px rgba(0,0,0,0.06);
      border-bottom-color: transparent;
    }

    .nav-container {
      display: flex;
      align-items: center;
      justify-content: space-between;
      width: 100%;
      max-width: 1200px;
      margin: 0 auto;
      padding: 0 20px;
    }

    .logo {
      font-size: 1.6rem;
      font-weight: 700;
      color: var(--primary);
      display: flex;
      align-items: center;
      gap: 6px;
      letter-spacing: -0.5px;
    }
    .logo svg {
      width: 28px;
      height: 28px;
    }

    .nav-links {
      display: flex;
      align-items: center;
      gap: 6px;
      flex-wrap: wrap;
    }

    .nav-chip {
      background: #F0EDE8;
      color: var(--text-main);
      padding: 6px 16px;
      border-radius: var(--radius-chip);
      font-size: 0.9rem;
      font-weight: 500;
      transition: var(--transition-smooth);
      white-space: nowrap;
    }
    .nav-chip:hover {
      background: var(--primary-soft);
      color: var(--primary);
    }
    .nav-chip.active {
      background: var(--primary-15);
      color: var(--primary);
      font-weight: 600;
    }

    .btn-primary {
      background: var(--primary);
      color: white;
      padding: 12px 28px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      font-size: 0.95rem;
      border: none;
      cursor: pointer;
      transition: var(--transition-smooth);
      box-shadow: 0 4px 10px rgba(255,107,74,0.25);
      white-space: nowrap;
      display: inline-block;
      text-align: center;
    }
    .btn-primary:hover {
      background: var(--primary-dark);
      box-shadow: 0 6px 16px rgba(255,107,74,0.35);
      transform: translateY(-1px);
    }

    .btn-outline {
      background: transparent;
      border: 2px solid var(--primary);
      color: var(--primary);
      padding: 10px 26px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      font-size: 0.95rem;
      cursor: pointer;
      transition: var(--transition-smooth);
      white-space: nowrap;
      display: inline-block;
    }
    .btn-outline:hover {
      background: var(--primary-soft);
      border-color: var(--primary-dark);
      color: var(--primary-dark);
    }

    .hamburger {
      display: none;
      flex-direction: column;
      gap: 5px;
      cursor: pointer;
      background: transparent;
      border: none;
      padding: 6px;
    }
    .hamburger span {
      width: 24px;
      height: 2.5px;
      background: var(--secondary-dark);
      border-radius: 4px;
      transition: 0.2s;
    }

    .mobile-menu {
      display: none;
      position: absolute;
      top: 72px;
      left: 0;
      width: 100%;
      background: rgba(247,245,242,0.98);
      backdrop-filter: blur(16px);
      border-bottom: 1px solid var(--border-light);
      flex-direction: column;
      padding: 20px;
      gap: 12px;
      box-shadow: 0 12px 24px rgba(0,0,0,0.06);
    }
    .mobile-menu.active {
      display: flex;
    }

    /* 区块通用 */
    section {
      padding: 100px 0;
      scroll-margin-top: 72px;
    }

    .bg-soft {
      background-color: var(--secondary-light);
    }
    .bg-dark {
      background-color: var(--secondary-dark);
      color: #F9F9F9;
    }

    /* 标题层级 */
    h1 {
      font-size: 3rem;
      font-weight: 700;
      line-height: 1.25;
      letter-spacing: -0.5px;
      color: var(--secondary-dark);
    }
    h2 {
      font-size: 2.25rem;
      font-weight: 700;
      line-height: 1.3;
      margin-bottom: 16px;
    }
    h3 {
      font-size: 1.4rem;
      font-weight: 600;
      line-height: 1.4;
    }

    .text-accent {
      color: var(--accent);
    }

    /* 卡片 */
    .card {
      background: var(--card-bg);
      border-radius: var(--radius-card);
      box-shadow: var(--shadow-sm);
      padding: 28px;
      transition: var(--transition-smooth);
      border: 1px solid var(--border-light);
    }
    .card:hover {
      box-shadow: var(--shadow-md);
      transform: translateY(-4px);
    }

    /* 数据大数字 */
    .big-number {
      font-size: 4rem;
      font-weight: 800;
      line-height: 1.1;
      background: linear-gradient(135deg, var(--primary) 0%, var(--accent) 100%);
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
      background-clip: text;
    }

    /* FAQ 手风琴 */
    .faq-item {
      border-bottom: 1px solid var(--border-light);
      padding: 20px 0;
      cursor: pointer;
    }
    .faq-question {
      font-weight: 600;
      font-size: 1.1rem;
      display: flex;
      justify-content: space-between;
      align-items: center;
    }
    .faq-icon {
      font-size: 1.4rem;
      transition: transform 0.3s;
      color: var(--primary);
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.35s ease;
      color: var(--text-secondary);
      line-height: 1.8;
    }
    .faq-item.active .faq-answer {
      max-height: 200px;
      padding-top: 12px;
    }
    .faq-item.active .faq-icon {
      transform: rotate(45deg);
    }

    /* 页脚 */
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1.2fr;
      gap: 40px;
    }
    .footer-links a {
      display: block;
      color: #9CA3AF;
      margin-bottom: 8px;
      transition: color 0.2s;
    }
    .footer-links a:hover {
      color: var(--primary);
    }

    @media (max-width: 1024px) {
      h1 { font-size: 2.5rem; }
      h2 { font-size: 2rem; }
      .big-number { font-size: 3.2rem; }
    }

    @media (max-width: 768px) {
      .nav-links { display: none; }
      .hamburger { display: flex; }
      .navbar { height: 64px; }
      section { padding: 70px 0; }
      h1 { font-size: 2.2rem; }
      h2 { font-size: 1.8rem; }
      .footer-grid { grid-template-columns: 1fr 1fr; }
      .container { padding: 0 24px; }
      .big-number { font-size: 2.8rem; }
    }

    @media (max-width: 640px) {
      section { padding: 50px 0; }
      h1 { font-size: 1.9rem; }
      .footer-grid { grid-template-columns: 1fr; }
    }