/* roulang page: index */
:root {
      --primary-deep: #0B1A3A;
      --accent-cyan: #2EE6D8;
      --highlight-purple: #7B4BFF;
      --bg-light: #F4F7FC;
      --card-white: #FFFFFF;
      --text-dark: #1a1f2e;
      --text-soft: #5a6275;
      --border-light: #e9edf4;
      --shadow-card: 0 12px 32px rgba(0,0,0,0.04), 0 4px 12px rgba(0,0,0,0.02);
      --shadow-hover: 0 20px 40px rgba(0,0,0,0.08), 0 8px 20px rgba(0,0,0,0.04);
      --radius-lg: 28px;
      --radius-card: 20px;
      --radius-btn: 50px;
      --radius-input: 12px;
      --font-title: "PingFang SC", "Microsoft YaHei", "Helvetica Neue", sans-serif;
      --transition: all 0.2s ease;
    }

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

    body {
      font-family: var(--font-title);
      background: var(--bg-light);
      color: var(--text-dark);
      line-height: 1.5;
      -webkit-font-smoothing: antialiased;
      overflow-x: hidden;
    }

    .container {
      max-width: 1280px;
      margin: 0 auto;
      padding-left: 24px;
      padding-right: 24px;
    }

    a { text-decoration: none; color: inherit; }
    img { display: block; max-width: 100%; height: auto; }

    /* 导航 */
    .nav-header {
      position: sticky;
      top: 0;
      z-index: 50;
      background: rgba(255,255,255,0.85);
      backdrop-filter: blur(12px);
      box-shadow: 0 6px 20px rgba(0,0,0,0.02);
      height: 72px;
      display: flex;
      align-items: center;
      transition: var(--transition);
    }

    .nav-container {
      display: flex;
      align-items: center;
      justify-content: space-between;
      width: 100%;
    }

    .logo {
      font-size: 24px;
      font-weight: 700;
      letter-spacing: 1.5px;
      color: var(--primary-deep);
      display: flex;
      align-items: center;
      gap: 8px;
    }
    .logo-icon {
      color: var(--accent-cyan);
      font-size: 28px;
    }

    .nav-links {
      display: flex;
      gap: 32px;
      align-items: center;
      font-weight: 500;
      color: #2a3349;
    }

    .nav-links a {
      padding: 6px 0;
      position: relative;
      font-size: 15px;
      transition: color 0.2s;
    }
    .nav-links a:hover,
    .nav-links a.active {
      color: var(--accent-cyan);
    }

    .nav-links a::after {
      content: '';
      position: absolute;
      bottom: 0;
      left: 0;
      width: 0;
      height: 2px;
      background: var(--accent-cyan);
      transition: width 0.2s;
    }
    .nav-links a:hover::after,
    .nav-links a.active::after {
      width: 100%;
    }

    .nav-cta-mobile {
      display: none;
    }

    .burger {
      display: none;
      flex-direction: column;
      gap: 5px;
      cursor: pointer;
      background: transparent;
      border: none;
    }
    .burger span {
      width: 24px;
      height: 2.5px;
      background: var(--primary-deep);
      border-radius: 4px;
      transition: var(--transition);
    }

    /* hero */
    #hero {
      padding: 48px 0 64px;
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 50px;
      align-items: center;
    }

    .hero-left {
      background: linear-gradient(135deg, #0b1a3a 0%, #1a1f4b 100%);
      color: white;
      padding: 48px 40px;
      border-radius: var(--radius-lg);
      box-shadow: var(--shadow-card);
    }

    .hero-left h1 {
      font-size: 48px;
      font-weight: 700;
      line-height: 1.2;
      margin-bottom: 16px;
    }
    .hero-sub {
      font-size: 18px;
      color: rgba(255,255,255,0.8);
      margin-bottom: 32px;
    }
    .hero-stats {
      display: flex;
      gap: 32px;
    }
    .stat-item h2 {
      font-size: 38px;
      font-weight: 700;
      color: var(--accent-cyan);
      line-height: 1.1;
    }
    .stat-item p {
      font-size: 14px;
      color: rgba(255,255,255,0.7);
    }

    .hero-right {
      background: var(--card-white);
      border-radius: var(--radius-lg);
      padding: 24px;
      box-shadow: var(--shadow-card);
      display: flex;
      flex-direction: column;
      align-items: center;
    }

    .hero-right .main-image {
      width: 100%;
      aspect-ratio: 4/3;
      object-fit: cover;
      border-radius: 20px;
      margin-bottom: 28px;
    }

    .btn-primary {
      background: var(--accent-cyan);
      color: var(--primary-deep);
      padding: 14px 40px;
      border-radius: var(--radius-btn);
      font-weight: 700;
      font-size: 17px;
      border: none;
      cursor: pointer;
      transition: all 0.25s;
      display: inline-block;
      text-align: center;
      box-shadow: 0 6px 18px rgba(46,230,216,0.25);
      letter-spacing: 0.5px;
    }
    .btn-primary:hover {
      background: #5FF0E4;
      box-shadow: 0 0 28px rgba(46,230,216,0.4);
      transform: translateY(-2px);
    }
    .btn-outline {
      background: transparent;
      border: 2px solid var(--accent-cyan);
      color: var(--primary-deep);
      padding: 12px 32px;
      border-radius: 50px;
      font-weight: 600;
      transition: 0.2s;
    }
    .btn-outline:hover {
      background: var(--accent-cyan);
      color: #0B1A3A;
    }

    section {
      padding: 64px 0;
    }

    h2 {
      font-size: 36px;
      font-weight: 700;
      margin-bottom: 16px;
      text-align: center;
    }
    .section-desc {
      text-align: center;
      color: var(--text-soft);
      max-width: 700px;
      margin: 0 auto 48px;
    }

    .highlights-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 28px;
    }
    .highlight-card {
      background: var(--card-white);
      padding: 34px 28px;
      border-radius: var(--radius-card);
      box-shadow: var(--shadow-card);
      transition: var(--transition);
    }
    .highlight-card:hover {
      transform: translateY(-6px);
      box-shadow: var(--shadow-hover);
    }
    .highlight-icon {
      font-size: 32px;
      color: var(--accent-cyan);
      margin-bottom: 20px;
    }
    .highlight-card h3 {
      font-size: 22px;
      margin-bottom: 8px;
    }

    .cases-grid {
      columns: 3 280px;
      column-gap: 28px;
    }
    .case-card {
      break-inside: avoid;
      margin-bottom: 28px;
      background: white;
      border-radius: var(--radius-card);
      overflow: hidden;
      box-shadow: var(--shadow-card);
      transition: var(--transition);
    }
    .case-card:hover {
      transform: translateY(-5px);
      box-shadow: var(--shadow-hover);
    }
    .case-img {
      width: 100%;
      display: block;
      height: 200px;
      object-fit: cover;
    }
    .case-info {
      padding: 18px;
    }
    .case-tag {
      color: var(--highlight-purple);
      font-weight: 600;
      font-size: 13px;
      margin-bottom: 4px;
    }

    .comparison-table {
      overflow-x: auto;
      border-radius: var(--radius-card);
      background: white;
      box-shadow: var(--shadow-card);
    }
    table {
      width: 100%;
      border-collapse: collapse;
      min-width: 720px;
    }
    th {
      background: var(--primary-deep);
      color: white;
      padding: 16px;
      text-align: center;
      font-weight: 600;
    }
    td {
      padding: 16px;
      text-align: center;
      border-bottom: 1px solid var(--border-light);
    }
    .highlight-col {
      background: rgba(46,230,216,0.05);
      border-left: 3px solid var(--accent-cyan);
    }

    .faq-item {
      border-bottom: 1px solid var(--border-light);
      padding: 16px 0;
    }
    .faq-question {
      font-weight: 700;
      cursor: pointer;
      display: flex;
      justify-content: space-between;
      align-items: center;
      font-size: 18px;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease;
      color: var(--text-soft);
      margin-top: 0;
    }
    .faq-item.open .faq-answer {
      max-height: 100px;
      margin-top: 12px;
    }

    .contact-wrapper {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 40px;
      background: var(--card-white);
      border-radius: var(--radius-lg);
      padding: 48px;
      box-shadow: var(--shadow-card);
    }
    .contact-form input, .contact-form textarea {
      width: 100%;
      padding: 14px;
      margin-bottom: 18px;
      border: 1px solid var(--border-light);
      border-radius: var(--radius-input);
      font-family: inherit;
      transition: 0.2s;
    }
    .contact-form input:focus, .contact-form textarea:focus {
      border-color: var(--accent-cyan);
      outline: none;
    }

    footer {
      background: var(--primary-deep);
      color: #d1d9e8;
      padding: 48px 0 20px;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 32px;
    }
    .footer-grid a {
      color: #bcc7da;
      font-size: 14px;
    }

    @media (max-width: 1024px) {
      #hero { grid-template-columns: 1fr; }
      .highlights-grid { grid-template-columns: repeat(2,1fr); }
      .footer-grid { grid-template-columns: repeat(2,1fr); }
    }

    @media (max-width: 768px) {
      .nav-links { display: none; }
      .burger { display: flex; }
      .highlights-grid { grid-template-columns: 1fr; }
      .contact-wrapper { grid-template-columns: 1fr; }
      .cases-grid { columns: 2; }
    }