/* roulang page: index */
:root {
      --deep-space: #1A1F36;
      --star-blue: #4E6EF2;
      --star-blue-light: #6E8EFB;
      --bg-light: #F5F6FA;
      --white: #FFFFFF;
      --text-primary: #1F2329;
      --text-secondary: #86909C;
      --success: #00B578;
      --warning: #FF9F0A;
      --error: #FA5151;
      --border-light: #E5E8EF;
      --shadow-card: 0 4px 12px rgba(0, 0, 0, 0.04);
      --shadow-card-hover: 0 8px 24px rgba(0, 0, 0, 0.08);
      --shadow-deep: 0 12px 28px rgba(0, 0, 0, 0.1);
      --radius-md: 12px;
      --radius-btn: 8px;
      --transition: 150ms 300ms cubic-bezier(0.4, 0, 0.2, 1);
      --font-family: -apple-system, BlinkMacSystemFont, "PingFang SC", "Microsoft YaHei", sans-serif;
    }
    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }
    body {
      font-family: var(--font-family);
      background-color: var(--bg-light);
      color: var(--text-primary);
      line-height: 1.5;
      overflow-x: hidden;
    }
    .container {
      max-width: 1200px;
      margin: 0 auto;
      padding: 0 24px;
    }
    /* 导航 */
    .nav {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      z-index: 999;
      transition: background 0.3s, box-shadow 0.3s, backdrop-filter 0.3s;
      padding: 16px 0;
      background: transparent;
    }
    .nav.scrolled {
      background: rgba(255, 255, 255, 0.95);
      backdrop-filter: blur(10px);
      box-shadow: 0 1px 4px rgba(0,0,0,0.05);
      padding: 12px 0;
    }
    .nav .container {
      display: flex;
      align-items: center;
      justify-content: space-between;
      flex-wrap: wrap;
    }
    .logo {
      font-size: 1.75rem;
      font-weight: 700;
      color: white;
      letter-spacing: 1px;
      transition: color 0.3s;
      text-decoration: none;
    }
    .nav.scrolled .logo {
      color: var(--deep-space);
    }
    .nav-links {
      display: flex;
      align-items: center;
      gap: 28px;
    }
    .nav-links a {
      text-decoration: none;
      color: white;
      font-weight: 500;
      font-size: 1rem;
      transition: color 0.2s, opacity 0.2s;
      opacity: 0.9;
    }
    .nav.scrolled .nav-links a {
      color: var(--text-primary);
    }
    .nav-links a:hover {
      opacity: 1;
      color: var(--star-blue);
    }
    .hamburger {
      display: none;
      flex-direction: column;
      gap: 5px;
      cursor: pointer;
      background: none;
      border: none;
    }
    .hamburger span {
      width: 24px;
      height: 2px;
      background: white;
      transition: 0.3s;
      display: block;
    }
    .nav.scrolled .hamburger span {
      background: var(--deep-space);
    }
    .mobile-menu {
      display: none;
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 100%;
      background: rgba(26, 31, 54, 0.97);
      backdrop-filter: blur(12px);
      flex-direction: column;
      align-items: center;
      justify-content: center;
      gap: 32px;
      z-index: 998;
    }
    .mobile-menu a {
      color: white;
      font-size: 1.5rem;
      text-decoration: none;
      font-weight: 500;
    }
    /* Hero */
    .hero {
      background: linear-gradient(135deg, #0A0E27 0%, #1A1F36 100%);
      min-height: 100vh;
      display: flex;
      align-items: center;
      position: relative;
      overflow: hidden;
      padding-top: 80px;
    }
    .hero::before {
      content: "";
      position: absolute;
      top: 0; left: 0; width: 100%; height: 100%;
      background-image: url('/assets/images/backpic/back-1.webp');
      background-size: cover;
      background-position: center;
      opacity: 0.25;
      z-index: 1;
    }
    .hero .container {
      display: flex;
      align-items: center;
      gap: 40px;
      position: relative;
      z-index: 2;
      flex-wrap: wrap;
    }
    .hero-left {
      flex: 1 1 500px;
    }
    .hero h1 {
      font-size: 3rem;
      font-weight: 700;
      line-height: 1.2;
      color: white;
      margin-bottom: 24px;
    }
    .hero-sub {
      font-size: 1.2rem;
      color: rgba(255,255,255,0.8);
      margin-bottom: 36px;
      max-width: 500px;
    }
    .btn-group {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
    }
    .btn-primary {
      background: var(--star-blue);
      color: white;
      border: none;
      padding: 14px 32px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      font-size: 1rem;
      cursor: pointer;
      transition: all 0.2s;
      text-decoration: none;
      display: inline-block;
      box-shadow: 0 4px 10px rgba(78,110,242,0.3);
    }
    .btn-primary:hover {
      background: var(--star-blue-light);
      transform: translateY(-2px);
      box-shadow: 0 8px 18px rgba(78,110,242,0.4);
    }
    .btn-outline {
      background: transparent;
      border: 1px solid var(--star-blue);
      color: var(--star-blue);
      padding: 14px 32px;
      border-radius: var(--btn-radius);
      font-weight: 600;
      transition: 0.2s;
      text-decoration: none;
    }
    .btn-outline:hover {
      background: rgba(78,110,242,0.08);
    }
    .hero-right {
      flex: 1 1 400px;
      display: flex;
      justify-content: center;
    }
    .hero-visual {
      width: 100%;
      max-width: 500px;
      height: 360px;
      background: rgba(255,255,255,0.05);
      border-radius: 24px;
      backdrop-filter: blur(8px);
      border: 1px solid rgba(255,255,255,0.15);
      display: flex;
      align-items: center;
      justify-content: center;
      color: white;
      font-size: 1.2rem;
      background-image: url('/assets/images/coverpic/cover-2.webp');
      background-size: cover;
      background-position: center;
    }
    /* 通用板块 */
    section {
      padding: 80px 0;
    }
    .section-title {
      font-size: 2.2rem;
      font-weight: 700;
      margin-bottom: 16px;
      color: var(--deep-space);
    }
    .section-sub {
      color: var(--text-secondary);
      margin-bottom: 48px;
      font-size: 1.1rem;
    }
    /* 服务卡片 非对称 */
    .services-grid {
      display: flex;
      gap: 24px;
      flex-wrap: wrap;
    }
    .service-card {
      background: var(--white);
      border-radius: var(--radius-md);
      padding: 32px;
      box-shadow: var(--shadow-card);
      flex: 1 1 280px;
      display: flex;
      align-items: flex-start;
      gap: 20px;
      transition: all 0.25s;
      position: relative;
    }
    .service-card:hover {
      box-shadow: var(--shadow-card-hover);
      transform: translateY(-4px);
    }
    .service-icon {
      background: #EEF1FF;
      width: 56px;
      height: 56px;
      border-radius: 16px;
      display: flex;
      align-items: center;
      justify-content: center;
      font-size: 1.8rem;
      color: var(--star-blue);
      flex-shrink: 0;
      transition: 0.2s;
    }
    .service-card:hover .service-icon {
      background: var(--star-blue);
      color: white;
    }
    .service-text h3 {
      font-size: 1.3rem;
      margin-bottom: 8px;
    }
    /* 数据深色条 */
    .stats {
      background: #0A0E27;
      color: white;
    }
    .stats-grid {
      display: flex;
      justify-content: space-around;
      flex-wrap: wrap;
      text-align: center;
      gap: 30px;
    }
    .stat-item h3 {
      font-size: 2.8rem;
      font-weight: 700;
      font-family: monospace;
    }
    .stat-item p {
      color: #ccc;
    }
    /* 解决方案图文 */
    .solution-row {
      display: flex;
      align-items: center;
      gap: 40px;
      margin-bottom: 60px;
      flex-wrap: wrap;
    }
    .solution-text {
      flex: 1 1 300px;
    }
    .solution-img {
      flex: 1 1 400px;
      background: rgba(255,255,255,0.7);
      backdrop-filter: blur(6px);
      border-radius: 20px;
      height: 280px;
      background-image: url('/assets/images/coverpic/cover-3.webp');
      background-size: cover;
      background-position: center;
      box-shadow: var(--shadow-card);
    }
    /* 案例卡片 */
    .cases-grid {
      display: flex;
      gap: 24px;
      flex-wrap: wrap;
    }
    .case-card {
      background: white;
      border-radius: var(--radius-md);
      overflow: hidden;
      box-shadow: var(--shadow-card);
      flex: 1 1 300px;
      transition: 0.2s;
    }
    .case-card:hover {
      box-shadow: var(--shadow-deep);
    }
    .case-img {
      height: 200px;
      background-size: cover;
      background-position: center;
    }
    .case-info {
      padding: 20px;
    }
    /* FAQ */
    .faq-grid {
      display: grid;
      grid-template-columns: repeat(2,1fr);
      gap: 20px;
    }
    .faq-item {
      background: white;
      border-radius: 12px;
      padding: 16px 20px;
      cursor: pointer;
      transition: 0.2s;
    }
    .faq-question {
      display: flex;
      align-items: center;
      gap: 12px;
      font-weight: 600;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease;
      padding-left: 32px;
      color: var(--text-secondary);
    }
    .faq-item.active {
      background: #F0F3FF;
    }
    .faq-item.active .faq-answer {
      max-height: 100px;
      margin-top: 8px;
    }
    /* CTA */
    .cta-section {
      background: #0A0E27;
      position: relative;
    }
    .cta-form {
      display: flex;
      max-width: 500px;
      margin: 24px auto 0;
      gap: 12px;
      flex-wrap: wrap;
      justify-content: center;
    }
    .cta-input {
      flex: 1;
      padding: 14px 18px;
      border-radius: 30px;
      border: 1px solid var(--border-light);
      background: white;
    }
    /* Footer */
    .footer {
      background: #1F2329;
      color: #ccc;
      padding: 60px 0 30px;
    }
    .footer-grid {
      display: flex;
      gap: 40px;
      flex-wrap: wrap;
    }
    .footer-col {
      flex: 1 1 180px;
    }
    @media (max-width: 768px) {
      .nav-links { display: none; }
      .hamburger { display: flex; }
      .hero h1 { font-size: 2.2rem; }
      .faq-grid { grid-template-columns: 1fr; }
      .hero-right { display: none; }
    }