/* roulang page: index */
:root {
      --primary: #1A73E8;
      --primary-deep: #1557B0;
      --accent: #FF6B35;
      --accent-hover: #E55A2B;
      --soft-blue: #E8F0FE;
      --bg: #F8FAFC;
      --card-bg: #FFFFFF;
      --text-main: #1E293B;
      --text-secondary: #64748B;
      --success: #0F9D58;
      --divider: #E2E8F0;
      --radius-card: 16px;
      --radius-btn: 50px;
      --radius-inner: 12px;
      --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.04), 0 4px 12px rgba(0, 0, 0, 0.02);
      --shadow-md: 0 6px 20px rgba(0, 0, 0, 0.06), 0 12px 28px rgba(0, 0, 0, 0.04);
      --shadow-lg: 0 12px 32px rgba(26, 115, 232, 0.12);
      --transition: 0.3s ease;
      --font-sans: "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", "Noto Sans SC", system-ui, sans-serif;
      --font-en: "Inter", "Segoe UI", system-ui, sans-serif;
      --header-height: 76px;
      --header-height-mobile: 60px;
    }

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

    html {
      scroll-behavior: smooth;
      font-size: 16px;
      background: var(--bg);
    }

    body {
      font-family: var(--font-sans);
      color: var(--text-main);
      line-height: 1.7;
      background-color: var(--bg);
      overflow-x: hidden;
      -webkit-font-smoothing: antialiased;
    }

    .container {
      max-width: 1200px;
      margin: 0 auto;
      padding: 0 24px;
    }

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

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

    button, .btn {
      cursor: pointer;
      font-family: var(--font-sans);
      border: none;
      outline: none;
      transition: var(--transition);
      display: inline-flex;
      align-items: center;
      justify-content: center;
      gap: 8px;
      font-weight: 600;
      letter-spacing: 0.3px;
    }

    h1, h2, h3, h4 {
      font-weight: 700;
      line-height: 1.3;
    }

    h1 {
      font-size: 3rem;
      letter-spacing: -0.5px;
      color: #0F172A;
    }

    h2 {
      font-size: 2.25rem;
      margin-bottom: 1rem;
      color: #1E293B;
    }

    h3 {
      font-size: 1.375rem;
      font-weight: 600;
    }

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

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

    /* 导航 */
    .site-header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: var(--header-height);
      background: rgba(255, 255, 255, 0.85);
      backdrop-filter: blur(12px);
      z-index: 1000;
      transition: background 0.3s, box-shadow 0.3s;
      border-bottom: 1px solid transparent;
    }

    .site-header.scrolled {
      background: #FFFFFF;
      box-shadow: 0 6px 20px rgba(0, 0, 0, 0.04);
      border-bottom: 1px solid var(--divider);
    }

    .header-inner {
      display: flex;
      align-items: center;
      justify-content: space-between;
      height: 100%;
    }

    .logo {
      font-size: 1.7rem;
      font-weight: 700;
      color: var(--primary);
      display: flex;
      align-items: center;
      gap: 6px;
      letter-spacing: -0.5px;
    }
    .logo span {
      color: var(--text-main);
      font-weight: 600;
    }

    .nav-links {
      display: flex;
      align-items: center;
      gap: 2.5rem;
      list-style: none;
    }

    .nav-links a {
      font-weight: 500;
      color: var(--text-main);
      position: relative;
      padding: 8px 0;
      font-size: 1rem;
    }

    .nav-links a::after {
      content: '';
      position: absolute;
      bottom: 0;
      left: 0;
      width: 0;
      height: 2px;
      background: var(--primary);
      transition: width 0.25s ease;
    }

    .nav-links a:hover::after,
    .nav-links a.active::after {
      width: 100%;
    }

    .btn-primary {
      background: var(--accent);
      color: white;
      padding: 0.7rem 2rem;
      border-radius: var(--radius-btn);
      font-weight: 600;
      box-shadow: 0 6px 14px rgba(255, 107, 53, 0.3);
    }

    .btn-primary:hover {
      background: var(--accent-hover);
      transform: scale(1.04);
      box-shadow: 0 10px 22px rgba(255, 107, 53, 0.4);
    }

    .btn-outline {
      background: transparent;
      border: 1.5px solid var(--primary);
      color: var(--primary);
      padding: 0.7rem 2rem;
      border-radius: var(--radius-btn);
    }

    .btn-outline:hover {
      background: var(--soft-blue);
    }

    .hamburger {
      display: none;
      flex-direction: column;
      gap: 5px;
      cursor: pointer;
    }
    .hamburger span {
      width: 26px;
      height: 2.5px;
      background: var(--text-main);
      border-radius: 4px;
    }

    /* 区块间距 */
    section {
      padding: 5rem 0;
    }

    /* Hero */
    .hero {
      padding: 9rem 0 6rem;
      background: linear-gradient(135deg, #F8FAFC 0%, #E8F0FE 100%);
      position: relative;
      overflow: hidden;
    }
    .hero-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 3rem;
      align-items: center;
    }
    .hero-content .badge {
      background: rgba(255,107,53,0.1);
      color: var(--accent);
      padding: 0.4rem 1.2rem;
      border-radius: 50px;
      font-weight: 500;
      display: inline-block;
      margin-bottom: 1.5rem;
    }
    .hero-buttons {
      display: flex;
      gap: 1rem;
      flex-wrap: wrap;
      margin-top: 2rem;
    }
    .trust-tag {
      display: flex;
      align-items: center;
      gap: 0.5rem;
      font-size: 0.9rem;
      color: var(--success);
      margin-top: 1.2rem;
    }
    .hero-image img {
      border-radius: 24px;
      box-shadow: var(--shadow-lg);
    }

    /* 卡片网格 */
    .cards-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 2rem;
      margin-top: 2.5rem;
    }
    .feature-card {
      background: var(--card-bg);
      padding: 2.2rem;
      border-radius: var(--radius-card);
      box-shadow: var(--shadow-sm);
      transition: var(--transition);
      text-align: center;
    }
    .feature-card:hover {
      transform: translateY(-8px);
      box-shadow: var(--shadow-lg);
    }
    .icon-circle {
      width: 70px;
      height: 70px;
      background: var(--soft-blue);
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      margin: 0 auto 1.5rem;
      font-size: 2.2rem;
      color: var(--primary);
    }

    /* 解决方案交替 */
    .solution-row {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 3rem;
      align-items: center;
      margin: 3rem 0;
    }
    .solution-img {
      border-radius: 24px;
      box-shadow: var(--shadow-md);
    }

    /* 数据区 */
    .stats-band {
      background: var(--soft-blue);
      border-radius: 32px;
      padding: 3rem 2rem;
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      text-align: center;
    }
    .stat-number {
      font-size: 2.8rem;
      font-weight: 700;
      color: var(--primary);
    }

    /* 评价滚动 */
    .reviews-scroll {
      display: flex;
      gap: 1.5rem;
      overflow-x: auto;
      scroll-snap-type: x mandatory;
      padding: 1rem 0 2rem;
    }
    .review-card {
      min-width: 300px;
      background: white;
      padding: 1.8rem;
      border-radius: 20px;
      box-shadow: var(--shadow-sm);
      scroll-snap-align: start;
    }

    /* FAQ */
    .faq-item {
      border-bottom: 1px solid var(--divider);
      padding: 1.5rem 0;
    }
    .faq-question {
      font-weight: 600;
      font-size: 1.2rem;
      display: flex;
      justify-content: space-between;
      cursor: pointer;
    }

    /* CTA Band */
    .cta-band {
      background: linear-gradient(135deg, #1A73E8, #0F4C9E);
      color: white;
      text-align: center;
      border-radius: 32px;
      padding: 4rem 2rem;
    }

    footer {
      background: #1E293B;
      color: #CBD5E1;
      padding: 3rem 0 2rem;
    }

    @media (max-width: 992px) {
      .hero-grid, .solution-row { grid-template-columns: 1fr; }
      .cards-grid { grid-template-columns: repeat(2, 1fr); }
      .stats-band { grid-template-columns: repeat(2, 1fr); }
      h1 { font-size: 2.5rem; }
    }
    @media (max-width: 768px) {
      .nav-links { display: none; }
      .hamburger { display: flex; }
      .cards-grid { grid-template-columns: 1fr; }
      .stats-band { grid-template-columns: 1fr 1fr; }
      h1 { font-size: 2rem; }
    }