/* roulang page: index */
:root {
      --primary: #E8452D;
      --primary-hover: #C0392B;
      --primary-soft: rgba(232, 69, 45, 0.1);
      --secondary: #1E1E1E;
      --bg-warm: #F5F0EB;
      --white: #FFFFFF;
      --accent: #FFB800;
      --text-main: #1E1E1E;
      --text-secondary: #666666;
      --border-light: #E0DCD7;
      --shadow-card: 0 4px 20px rgba(0,0,0,0.04);
      --shadow-hover: 0 8px 30px rgba(0,0,0,0.08);
      --radius-sm: 8px;
      --radius-md: 12px;
      --radius-full: 50px;
      --font-sans: "PingFang SC", "Microsoft YaHei", "Helvetica Neue", Helvetica, Arial, sans-serif;
      --max-width: 1200px;
    }

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

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

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

    .container {
      max-width: var(--max-width);
      margin: 0 auto;
      padding: 0 20px;
    }

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

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

    button, .button {
      cursor: pointer;
      font-family: inherit;
      display: inline-block;
      border: none;
      background: none;
    }

    /* 导航 */
    .header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 72px;
      background: var(--white);
      box-shadow: 0 2px 10px rgba(0,0,0,0.03);
      z-index: 1000;
      display: flex;
      align-items: center;
      justify-content: center;
      transition: background 0.3s;
    }

    .nav-bar {
      display: flex;
      justify-content: space-between;
      align-items: center;
      width: 100%;
      max-width: var(--max-width);
      padding: 0 20px;
    }

    .logo {
      font-size: 24px;
      font-weight: 700;
      color: var(--primary);
      letter-spacing: 1px;
      display: flex;
      align-items: center;
      gap: 8px;
    }

    .logo svg {
      width: 32px;
      height: 32px;
    }

    .nav-menu {
      display: flex;
      gap: 32px;
      list-style: none;
      align-items: center;
    }

    .nav-menu a {
      font-size: 15px;
      font-weight: 500;
      color: var(--text-main);
      padding: 8px 0;
      border-bottom: 2px solid transparent;
      transition: color 0.2s, border-color 0.2s;
      white-space: nowrap;
    }

    .nav-menu a:hover,
    .nav-menu a.active {
      color: var(--primary);
      border-bottom-color: var(--primary);
    }

    .hamburger {
      display: none;
      flex-direction: column;
      gap: 6px;
      background: none;
      border: none;
      padding: 10px;
      z-index: 1001;
      cursor: pointer;
    }

    .hamburger span {
      width: 26px;
      height: 2px;
      background: var(--secondary);
      transition: 0.3s;
      display: block;
      border-radius: 2px;
    }

    .mobile-menu {
      display: none;
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 100vh;
      background: var(--white);
      z-index: 999;
      flex-direction: column;
      justify-content: center;
      align-items: center;
      gap: 28px;
      font-size: 20px;
      transform: translateY(-100%);
      transition: transform 0.4s ease;
      list-style: none;
    }

    .mobile-menu.open {
      transform: translateY(0);
    }

    /* Hero */
    .hero {
      min-height: 100vh;
      display: flex;
      align-items: center;
      background-image: url('/assets/images/backpic/back-1.webp');
      background-size: cover;
      background-position: center;
      position: relative;
      color: var(--white);
      margin-top: 0;
    }

    .hero::before {
      content: '';
      position: absolute;
      inset: 0;
      background: rgba(0,0,0,0.55);
    }

    .hero-content {
      position: relative;
      max-width: 700px;
      padding: 40px 0;
    }

    .hero h1 {
      font-size: 48px;
      font-weight: 700;
      line-height: 1.2;
      letter-spacing: -0.5px;
      margin-bottom: 24px;
    }

    .hero p {
      font-size: 18px;
      line-height: 1.7;
      margin-bottom: 32px;
      color: rgba(255,255,255,0.9);
    }

    .btn-group {
      display: flex;
      flex-wrap: wrap;
      gap: 16px;
    }

    .btn-primary {
      background: var(--primary);
      color: white;
      padding: 14px 32px;
      border-radius: var(--radius-sm);
      font-weight: 600;
      font-size: 16px;
      transition: background 0.2s, transform 0.1s;
      border: 2px solid var(--primary);
    }

    .btn-primary:hover {
      background: var(--primary-hover);
      border-color: var(--primary-hover);
    }

    .btn-outline {
      background: transparent;
      color: white;
      padding: 14px 32px;
      border-radius: var(--radius-sm);
      font-weight: 600;
      font-size: 16px;
      border: 2px solid white;
      transition: all 0.2s;
    }

    .btn-outline:hover {
      background: white;
      color: var(--secondary);
    }

    /* 通用区块 */
    section {
      padding: 120px 0;
    }

    .section-title {
      font-size: 36px;
      font-weight: 600;
      line-height: 1.3;
      margin-bottom: 48px;
      text-align: center;
      color: var(--secondary);
    }

    /* 优势卡片 */
    .advantages-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 24px;
    }

    .adv-card {
      background: var(--white);
      border-radius: var(--radius-md);
      padding: 32px 20px;
      text-align: center;
      box-shadow: var(--shadow-card);
      transition: 0.3s ease;
    }

    .adv-card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-hover);
    }

    .adv-icon {
      width: 56px;
      height: 56px;
      background: var(--primary-soft);
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      margin: 0 auto 20px;
      color: var(--primary);
    }

    /* 服务卡片 */
    .service-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }

    .service-card {
      background: var(--white);
      border-radius: var(--radius-md);
      overflow: hidden;
      box-shadow: var(--shadow-card);
      transition: 0.3s ease;
    }

    .service-card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-hover);
    }

    .card-img {
      aspect-ratio: 16 / 9;
      background: #E0DCD7;
      overflow: hidden;
    }

    .card-img img {
      width: 100%;
      height: 100%;
      object-fit: cover;
    }

    .card-body {
      padding: 24px;
    }

    .card-body h3 {
      font-size: 20px;
      font-weight: 600;
      margin-bottom: 8px;
    }

    .card-body p {
      color: var(--text-secondary);
      font-size: 14px;
      margin-bottom: 16px;
    }

    .tag {
      display: inline-block;
      background: var(--primary-soft);
      color: var(--primary);
      padding: 4px 12px;
      border-radius: 50px;
      font-size: 13px;
      font-weight: 500;
      margin-right: 8px;
    }

    /* 数据深色区 */
    .dark-bg {
      background: var(--secondary);
      color: white;
    }

    .stats-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      text-align: center;
      gap: 32px;
    }

    .stat-number {
      font-size: 48px;
      font-weight: 700;
      color: var(--accent);
      margin-bottom: 8px;
    }

    /* 案例 */
    .case-grid {
      display: grid;
      grid-template-columns: repeat(2, 1fr);
      gap: 24px;
    }

    .case-card {
      background: var(--white);
      border-radius: var(--radius-md);
      display: flex;
      box-shadow: var(--shadow-card);
      transition: 0.3s;
    }

    .case-card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-hover);
    }

    .case-img {
      width: 200px;
      min-height: 150px;
      background: #ddd;
      flex-shrink: 0;
    }

    .case-img img {
      width: 100%;
      height: 100%;
      object-fit: cover;
    }

    .case-info {
      padding: 24px;
    }

    /* 流程 */
    .steps {
      display: flex;
      justify-content: center;
      flex-wrap: wrap;
      gap: 40px;
      position: relative;
    }

    .step-item {
      text-align: center;
      flex: 1;
      min-width: 160px;
    }

    .step-circle {
      width: 48px;
      height: 48px;
      background: var(--primary);
      color: white;
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      font-weight: 700;
      margin: 0 auto 16px;
    }

    /* FAQ */
    .faq-list {
      max-width: 800px;
      margin: 0 auto;
    }

    .faq-item {
      border-bottom: 1px solid var(--border-light);
      background: var(--white);
      margin-bottom: 8px;
      border-radius: var(--radius-sm);
    }

    .faq-question {
      width: 100%;
      text-align: left;
      padding: 20px;
      font-weight: 600;
      display: flex;
      justify-content: space-between;
      align-items: center;
      background: none;
      border: none;
      font-size: 16px;
      cursor: pointer;
    }

    .faq-answer {
      padding: 0 20px 20px;
      display: none;
      color: var(--text-secondary);
    }

    .faq-item.active .faq-answer {
      display: block;
    }

    .faq-item.active .faq-question {
      color: var(--primary);
    }

    /* CTA 横幅 */
    .cta-band {
      background: var(--primary);
      color: white;
      text-align: center;
      padding: 80px 20px;
    }

    /* 页脚 */
    .footer {
      background: var(--secondary);
      color: #ccc;
      padding: 60px 0 30px;
    }

    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 40px;
    }

    .footer a {
      color: #ccc;
      display: block;
      margin-bottom: 8px;
    }

    .footer a:hover {
      color: white;
    }

    @media (max-width: 768px) {
      .nav-menu { display: none; }
      .hamburger { display: flex; }
      .mobile-menu { display: flex; }
      .hero h1 { font-size: 32px; }
      .advantages-grid, .service-grid, .stats-grid { grid-template-columns: repeat(2, 1fr); }
      .case-grid { grid-template-columns: 1fr; }
      .case-card { flex-direction: column; }
      .case-img { width: 100%; height: 180px; }
      .footer-grid { grid-template-columns: 1fr 1fr; }
      section { padding: 80px 0; }
    }

    @media (max-width: 480px) {
      .advantages-grid, .service-grid, .stats-grid { grid-template-columns: 1fr; }
      .btn-group .btn-primary, .btn-group .btn-outline { width: 100%; text-align: center; }
    }