/* roulang page: index */
/* 设计变量与全局重置 */
    :root {
      --primary: #4E6EF2;
      --primary-dark: #3B5BDB;
      --secondary: #6C5CE7;
      --secondary-dark: #5A4BD1;
      --success: #00B578;
      --warning: #FF9F0A;
      --danger: #FA5151;
      --text-primary: #1F2329;
      --text-secondary: #86909C;
      --bg-light: #F5F6FA;
      --bg-white: #FFFFFF;
      --border-light: #E8EAED;
      --gradient-main: linear-gradient(135deg, #4E6EF2 0%, #6C5CE7 100%);
      --gradient-hover: linear-gradient(135deg, #3B5BDB 0%, #5A4BD1 100%);
      --radius-sm: 8px;
      --radius-md: 12px;
      --radius-lg: 24px;
      --shadow-card: 0 2px 12px rgba(0,0,0,0.04);
      --shadow-hover: 0 8px 24px rgba(0,0,0,0.08);
      --font-sans: -apple-system, BlinkMacSystemFont, "PingFang SC", "Helvetica Neue", "Microsoft YaHei", sans-serif;
      --container-max: 1200px;
      --nav-height: 64px;
      --mobile-nav-height: 56px;
    }

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

    html {
      scroll-behavior: smooth;
      scroll-padding-top: var(--nav-height);
    }

    body {
      font-family: var(--font-sans);
      background-color: var(--bg-light);
      color: var(--text-primary);
      line-height: 1.6;
      font-size: 16px;
      -webkit-font-smoothing: antialiased;
    }

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

    a {
      text-decoration: none;
      color: inherit;
      transition: color 0.2s ease;
    }

    button {
      font-family: inherit;
      cursor: pointer;
      border: none;
      background: none;
    }

    .container {
      max-width: var(--container-max);
      margin: 0 auto;
      padding: 0 24px;
    }

    /* 区块通用间距 */
    .section {
      padding: 80px 0;
    }

    .section-title {
      font-size: 28px;
      font-weight: 600;
      line-height: 1.4;
      text-align: center;
      margin-bottom: 16px;
      color: var(--text-primary);
    }

    .section-subtitle {
      font-size: 16px;
      color: var(--text-secondary);
      text-align: center;
      max-width: 680px;
      margin: 0 auto 48px;
      line-height: 1.6;
    }

    /* 按钮体系 */
    .btn {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      font-weight: 500;
      font-size: 16px;
      border-radius: var(--radius-sm);
      transition: all 0.25s ease;
      padding: 12px 28px;
      line-height: 1.2;
      text-align: center;
      white-space: nowrap;
    }

    .btn-primary {
      background: var(--gradient-main);
      color: white;
      box-shadow: 0 4px 10px rgba(78, 110, 242, 0.3);
    }

    .btn-primary:hover {
      background: var(--gradient-hover);
      box-shadow: 0 6px 16px rgba(78, 110, 242, 0.4);
      transform: translateY(-1px);
      color: white;
    }

    .btn-outline {
      background: rgba(255,255,255,0.15);
      backdrop-filter: blur(8px);
      border: 1px solid rgba(255,255,255,0.3);
      color: white;
    }

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

    .btn-white {
      background: white;
      color: var(--primary);
      box-shadow: 0 4px 12px rgba(0,0,0,0.06);
    }

    .btn-white:hover {
      background: #f0f2ff;
      color: var(--primary-dark);
    }

    /* 导航样式 */
    .navbar {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: var(--nav-height);
      background: rgba(255,255,255,0.95);
      backdrop-filter: blur(12px);
      border-bottom: 1px solid var(--border-light);
      z-index: 1000;
      display: flex;
      align-items: center;
      transition: background 0.3s;
    }

    .nav-container {
      display: flex;
      align-items: center;
      justify-content: space-between;
      width: 100%;
      max-width: var(--container-max);
      margin: 0 auto;
      padding: 0 24px;
    }

    .logo {
      font-size: 22px;
      font-weight: 700;
      color: var(--text-primary);
      letter-spacing: 0.5px;
    }

    .nav-menu {
      display: flex;
      align-items: center;
      gap: 32px;
    }

    .nav-link {
      font-size: 15px;
      color: var(--text-primary);
      position: relative;
      padding: 4px 0;
      font-weight: 500;
      transition: color 0.2s;
    }

    .nav-link:hover,
    .nav-link.active {
      color: var(--primary);
    }

    .nav-link.active::after {
      content: '';
      position: absolute;
      bottom: -8px;
      left: 0;
      width: 100%;
      height: 2px;
      background: var(--primary);
      border-radius: 2px;
    }

    .nav-cta {
      margin-left: 16px;
    }

    .hamburger {
      display: none;
      flex-direction: column;
      justify-content: center;
      gap: 5px;
      width: 28px;
      height: 28px;
      cursor: pointer;
      background: transparent;
      border: none;
    }

    .hamburger span {
      display: block;
      height: 2px;
      background: var(--text-primary);
      border-radius: 2px;
      transition: all 0.3s ease;
      width: 100%;
    }

    .mobile-menu {
      display: none;
    }

    /* Hero */
    .hero {
      min-height: 100vh;
      display: flex;
      align-items: center;
      background: linear-gradient(180deg, rgba(30,35,50,0.7) 0%, rgba(15,20,35,0.85) 100%), url('/assets/images/backpic/back-1.webp') center/cover no-repeat;
      color: white;
      padding-top: var(--nav-height);
    }

    .hero-content {
      max-width: 680px;
    }

    .hero h1 {
      font-size: 40px;
      font-weight: 700;
      line-height: 1.3;
      margin-bottom: 20px;
      text-shadow: 0 4px 12px rgba(0,0,0,0.3);
    }

    .hero p {
      font-size: 18px;
      color: rgba(255,255,255,0.85);
      margin-bottom: 32px;
      max-width: 600px;
    }

    .hero-buttons {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
    }

    /* 核心优势 */
    .advantages-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }

    .adv-item {
      text-align: center;
      padding: 0 12px;
    }

    .adv-icon {
      width: 80px;
      height: 80px;
      background: #EEF1FE;
      border-radius: var(--radius-md);
      display: flex;
      align-items: center;
      justify-content: center;
      margin: 0 auto 20px;
      color: var(--primary);
      font-size: 36px;
    }

    .adv-item h3 {
      font-size: 20px;
      font-weight: 600;
      margin-bottom: 12px;
    }

    .adv-item p {
      font-size: 14px;
      color: var(--text-secondary);
      max-width: 260px;
      margin: 0 auto;
    }

    /* 服务板块 */
    .service-row {
      display: flex;
      align-items: center;
      gap: 48px;
      margin-bottom: 80px;
    }

    .service-row:last-child {
      margin-bottom: 0;
    }

    .service-img {
      flex: 1;
      border-radius: var(--radius-md);
      overflow: hidden;
      box-shadow: var(--shadow-card);
      height: 360px;
    }

    .service-img img {
      width: 100%;
      height: 100%;
      object-fit: cover;
      border-radius: var(--radius-md);
    }

    .service-text {
      flex: 1;
    }

    .service-text h2 {
      font-size: 28px;
      font-weight: 600;
      margin-bottom: 16px;
    }

    .service-text p {
      color: var(--text-secondary);
      margin-bottom: 20px;
      line-height: 1.6;
    }

    .service-list {
      list-style: none;
      margin-bottom: 20px;
    }

    .service-list li {
      font-size: 14px;
      margin-bottom: 10px;
      display: flex;
      align-items: center;
      gap: 8px;
    }

    .service-list li::before {
      content: '';
      width: 8px;
      height: 8px;
      background: var(--primary);
      border-radius: 50%;
      display: inline-block;
    }

    .link-more {
      color: var(--primary);
      font-weight: 500;
      font-size: 15px;
      display: inline-flex;
      align-items: center;
      gap: 4px;
    }

    .link-more:hover {
      text-decoration: underline;
    }

    /* 数据区 */
    .data-bg {
      background: var(--bg-light);
    }

    .data-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      text-align: center;
      gap: 24px;
    }

    .data-item .number {
      font-size: 36px;
      font-weight: 700;
      color: var(--primary);
      line-height: 1.2;
    }

    .data-item .desc {
      font-size: 14px;
      color: var(--text-secondary);
      margin-top: 8px;
    }

    /* 案例卡片 */
    .cases-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }

    .case-card {
      background: var(--bg-white);
      border-radius: var(--radius-md);
      box-shadow: var(--shadow-card);
      overflow: hidden;
      transition: all 0.25s ease;
    }

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

    .case-img {
      height: 200px;
      overflow: hidden;
    }

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

    .case-body {
      padding: 20px;
    }

    .case-tag {
      display: inline-block;
      background: #EEF1FE;
      color: var(--primary);
      font-size: 12px;
      padding: 2px 10px;
      border-radius: 4px;
      margin-bottom: 12px;
    }

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

    .case-body p {
      font-size: 14px;
      color: var(--text-secondary);
      display: -webkit-box;
      -webkit-line-clamp: 2;
      -webkit-box-orient: vertical;
      overflow: hidden;
    }

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

    .faq-item {
      background: var(--bg-white);
      border-bottom: 1px solid var(--border-light);
    }

    .faq-question {
      width: 100%;
      display: flex;
      justify-content: space-between;
      align-items: center;
      padding: 16px 20px;
      font-size: 16px;
      font-weight: 500;
      color: var(--text-primary);
      background: transparent;
      border: none;
      cursor: pointer;
      text-align: left;
    }

    .faq-icon {
      font-size: 20px;
      color: var(--text-secondary);
      transition: transform 0.25s ease;
    }

    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease, padding 0.3s ease;
      padding: 0 20px;
      color: var(--text-secondary);
      font-size: 14px;
    }

    .faq-item.active .faq-answer {
      max-height: 200px;
      padding: 0 20px 16px;
    }

    .faq-item.active .faq-icon {
      transform: rotate(45deg);
      color: var(--primary);
    }

    /* CTA */
    .cta-section {
      background: var(--gradient-main);
      padding: 80px 0;
      text-align: center;
      color: white;
    }

    .cta-section h2 {
      font-size: 28px;
      font-weight: 600;
      margin-bottom: 16px;
    }

    .cta-section p {
      color: rgba(255,255,255,0.8);
      margin-bottom: 32px;
    }

    .cta-buttons {
      display: flex;
      justify-content: center;
      gap: 16px;
      flex-wrap: wrap;
    }

    .search-decor {
      margin-top: 40px;
      max-width: 400px;
      margin-left: auto;
      margin-right: auto;
      background: rgba(255,255,255,0.2);
      border-radius: 24px;
      padding: 10px 24px;
      display: flex;
      align-items: center;
      color: rgba(255,255,255,0.7);
      font-size: 14px;
      backdrop-filter: blur(8px);
    }

    /* Footer */
    .footer {
      background: #1F2329;
      color: white;
      padding: 60px 0 20px;
    }

    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1.5fr;
      gap: 40px;
      margin-bottom: 40px;
    }

    .footer-col h4 {
      font-size: 18px;
      margin-bottom: 20px;
      font-weight: 600;
    }

    .footer-col p, .footer-col a {
      font-size: 14px;
      color: #86909C;
      line-height: 1.8;
      display: block;
    }

    .footer-col a:hover {
      color: white;
    }

    .copyright {
      border-top: 1px solid rgba(255,255,255,0.1);
      padding-top: 20px;
      text-align: center;
      font-size: 12px;
      color: #86909C;
    }

    /* 响应式 */
    @media (max-width: 1024px) {
      .advantages-grid, .cases-grid {
        grid-template-columns: repeat(2, 1fr);
      }
    }

    @media (max-width: 768px) {
      :root {
        --nav-height: 56px;
      }
      .navbar {
        height: var(--mobile-nav-height);
      }
      .nav-menu {
        display: none;
      }
      .hamburger {
        display: flex;
      }
      .mobile-menu {
        position: fixed;
        top: var(--mobile-nav-height);
        left: 0;
        width: 100%;
        background: white;
        flex-direction: column;
        padding: 24px;
        gap: 24px;
        box-shadow: 0 10px 20px rgba(0,0,0,0.05);
        transform: translateY(-10px);
        opacity: 0;
        pointer-events: none;
        transition: all 0.25s ease;
        display: flex;
        z-index: 999;
      }
      .mobile-menu.open {
        opacity: 1;
        transform: translateY(0);
        pointer-events: auto;
      }
      .mobile-menu .nav-link {
        font-size: 18px;
        padding: 8px 0;
        border-bottom: 1px solid var(--border-light);
      }
      .section {
        padding: 60px 0;
      }
      .hero h1 {
        font-size: 28px;
      }
      .service-row {
        flex-direction: column;
        gap: 32px;
      }
      .service-row.reverse {
        flex-direction: column-reverse;
      }
      .advantages-grid, .cases-grid, .data-grid {
        grid-template-columns: 1fr;
      }
      .footer-grid {
        grid-template-columns: 1fr 1fr;
      }
    }

    @media (max-width: 520px) {
      .footer-grid {
        grid-template-columns: 1fr;
      }
    }