/* roulang page: index */
:root {
      --primary-deep: #0A1F2E;
      --ocean-blue: #1B5A7A;
      --accent-cyan: #00B4D8;
      --bg-warm: #F7F7F5;
      --text-primary: #0A1F2E;
      --text-body: #2C3E50;
      --text-muted: #6B7B8D;
      --card-bg: #FFFFFF;
      --border-light: #E2E6EA;
      --shadow-sm: 0 2px 12px rgba(10,31,46,0.06);
      --shadow-md: 0 8px 24px rgba(10,31,46,0.12);
      --radius-card: 12px;
      --radius-pill: 30px;
      --transition-base: 0.25s ease;
      --font-sans: "PingFang SC","Microsoft YaHei","Helvetica Neue",sans-serif;
    }

    *, *::before, *::after {
      box-sizing: border-box;
    }

    body {
      font-family: var(--font-sans);
      background-color: var(--bg-warm);
      color: var(--text-body);
      line-height: 1.75;
      margin: 0;
      padding: 0;
      -webkit-font-smoothing: antialiased;
    }

    a {
      color: var(--ocean-blue);
      text-decoration: none;
      transition: color var(--transition-base), text-decoration var(--transition-base);
    }
    a:hover {
      color: var(--accent-cyan);
      text-decoration: underline;
    }

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

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

    /* 导航吸顶 */
    .site-header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      z-index: 99;
      background: rgba(255,255,255,0.92);
      backdrop-filter: blur(12px);
      box-shadow: 0 1px 8px rgba(10,31,46,0.04);
      transition: background var(--transition-base), box-shadow var(--transition-base);
    }
    .header-inner {
      display: flex;
      align-items: center;
      justify-content: space-between;
      height: 56px;
      padding: 0 24px;
      max-width: 1200px;
      margin: 0 auto;
    }
    .logo {
      font-size: 1.6rem;
      font-weight: 700;
      letter-spacing: -0.5px;
      color: var(--primary-deep);
      white-space: nowrap;
    }
    .logo i {
      color: var(--accent-cyan);
      margin-right: 6px;
    }
    .nav-links {
      display: flex;
      gap: 28px;
      list-style: none;
      margin: 0;
      padding: 0;
    }
    .nav-links a {
      font-weight: 500;
      font-size: 0.95rem;
      color: var(--text-body);
      padding: 6px 0;
      border-bottom: 2px solid transparent;
      transition: border-color var(--transition-base), color var(--transition-base);
      text-decoration: none;
    }
    .nav-links a:hover,
    .nav-links a.active {
      color: var(--accent-cyan);
      border-bottom-color: var(--accent-cyan);
      text-decoration: none;
    }
    .search-trigger {
      background: none;
      border: none;
      font-size: 1.2rem;
      color: var(--text-body);
      cursor: pointer;
      transition: color var(--transition-base);
    }
    .search-trigger:hover { color: var(--accent-cyan); }
    .mobile-toggle {
      display: none;
      background: none;
      border: none;
      font-size: 1.5rem;
      color: var(--primary-deep);
    }

    /* 移动端导航 */
    @media (max-width: 768px) {
      .nav-links {
        display: none;
        position: absolute;
        top: 56px;
        left: 0;
        width: 100%;
        background: white;
        flex-direction: column;
        padding: 20px 24px;
        box-shadow: var(--shadow-md);
        gap: 16px;
      }
      .nav-links.show { display: flex; }
      .mobile-toggle { display: block; }
      .search-trigger { margin-left: auto; margin-right: 12px; }
    }

    /* 区块通用 */
    section {
      padding: 90px 0;
    }
    .section-title {
      font-size: 2.4rem;
      font-weight: 600;
      color: var(--text-primary);
      margin-bottom: 12px;
      letter-spacing: -0.3px;
    }
    .section-sub {
      font-size: 1.1rem;
      color: var(--text-muted);
      margin-bottom: 48px;
    }

    /* Hero */
    #hero {
      background: linear-gradient(135deg, #f0f2f5 0%, #ffffff 100%);
      padding-top: 130px;
      padding-bottom: 100px;
      position: relative;
    }
    .hero-grid {
      display: flex;
      align-items: center;
      gap: 40px;
    }
    .hero-text h1 {
      font-size: 3.2rem;
      font-weight: 700;
      color: var(--primary-deep);
      line-height: 1.2;
      margin-bottom: 20px;
    }
    .hero-text p {
      font-size: 1.2rem;
      color: var(--text-body);
      margin-bottom: 32px;
    }
    .btn {
      display: inline-block;
      font-weight: 600;
      border-radius: var(--radius-pill);
      padding: 14px 36px;
      text-align: center;
      transition: all var(--transition-base);
      cursor: pointer;
      text-decoration: none;
      border: 2px solid transparent;
    }
    .btn-primary {
      background: var(--accent-cyan);
      color: white;
      border-color: var(--accent-cyan);
    }
    .btn-primary:hover {
      background: #0096B4;
      border-color: #0096B4;
      box-shadow: 0 6px 18px rgba(0,180,216,0.3);
      text-decoration: none;
      color: white;
    }
    .btn-outline {
      background: transparent;
      color: var(--ocean-blue);
      border-color: var(--ocean-blue);
    }
    .btn-outline:hover {
      background: rgba(27,90,122,0.08);
      text-decoration: none;
    }
    .hero-image img {
      border-radius: 24px;
      box-shadow: var(--shadow-md);
    }

    /* 优势 */
    #advantages {
      background: white;
    }
    .adv-grid {
      display: grid;
      grid-template-columns: repeat(4,1fr);
      gap: 30px;
    }
    .adv-item {
      text-align: center;
    }
    .adv-icon {
      font-size: 2.4rem;
      color: var(--ocean-blue);
      margin-bottom: 16px;
    }

    /* 数据深色块 */
    #data {
      background: var(--primary-deep);
      color: white;
    }
    .data-grid {
      display: flex;
      justify-content: space-around;
      flex-wrap: wrap;
      gap: 30px;
    }
    .data-item {
      text-align: center;
    }
    .data-number {
      font-size: 3rem;
      font-weight: 700;
      color: var(--accent-cyan);
    }

    /* 服务非对称 */
    #services .service-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 30px;
    }
    .service-main {
      grid-row: span 2;
      background: white;
      border-radius: var(--radius-card);
      padding: 36px;
      box-shadow: var(--shadow-sm);
    }
    .service-card {
      background: white;
      border-radius: var(--radius-card);
      padding: 28px;
      box-shadow: var(--shadow-sm);
      transition: all var(--transition-base);
    }
    .service-card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-md);
    }

    /* 案例 */
    .case-grid {
      display: grid;
      grid-template-columns: repeat(3,1fr);
      gap: 30px;
    }
    .case-card img {
      border-radius: 8px;
      transition: transform 0.3s ease;
    }
    .case-card:hover img {
      transform: scale(1.03);
    }

    /* 流程 */
    .steps {
      display: flex;
      justify-content: space-between;
    }
    .step {
      text-align: center;
      flex:1;
    }
    .step-circle {
      width: 48px;
      height: 48px;
      background: var(--accent-cyan);
      color: white;
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      margin: 0 auto 16px;
      font-weight: 700;
    }

    /* FAQ */
    .accordion-item {
      background: white;
      border-radius: var(--radius-card);
      margin-bottom: 12px;
      box-shadow: var(--shadow-sm);
    }
    .accordion-title {
      background: none;
      border: none;
      width: 100%;
      text-align: left;
      font-weight: 600;
      padding: 20px 24px;
      font-size: 1.1rem;
    }

    /* CTA */
    #cta {
      background: var(--primary-deep);
      text-align: center;
      color: white;
    }

    /* Footer */
    #footer {
      background: #06161F;
      color: #b0c4d0;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 30px;
    }

    @media (max-width: 1024px) {
      .adv-grid { grid-template-columns: repeat(2,1fr); }
      .case-grid { grid-template-columns: repeat(2,1fr); }
      .service-grid { grid-template-columns: 1fr; }
      .steps { flex-wrap: wrap; }
      .hero-grid { flex-direction: column; }
    }
    @media (max-width: 640px) {
      .section-title { font-size: 1.8rem; }
      .adv-grid, .case-grid, .footer-grid { grid-template-columns: 1fr; }
      .data-grid { flex-direction: column; }
    }