/* roulang page: index */
:root {
      --deep-black-blue: #0A0E27;
      --electric-cyan: #00F0FF;
      --competition-red: #FF4655;
      --bg-light: #F5F7FB;
      --card-white: #FFFFFF;
      --text-dark: #1E2A3A;
      --text-muted: rgba(255,255,255,0.65);
      --shadow-sm: 0 4px 20px rgba(10,14,39,0.06);
      --shadow-hover: 0 8px 30px rgba(10,14,39,0.12);
      --radius-card: 16px;
      --radius-btn: 50px;
      --radius-input: 8px;
      --font-heading: "PingFang SC", "Microsoft YaHei", "Helvetica Neue", sans-serif;
      --transition: 0.25s ease;
    }
    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }
    body {
      font-family: var(--font-heading);
      background-color: var(--bg-light);
      color: var(--text-dark);
      line-height: 1.8;
      font-size: 16px;
      -webkit-font-smoothing: antialiased;
    }
    .container {
      max-width: 1280px;
      margin: 0 auto;
      padding: 0 32px;
    }
    h1, h2, h3 {
      font-weight: 700;
      letter-spacing: -0.02em;
    }
    h1 {
      font-size: 48px;
      line-height: 1.2;
    }
    h2 {
      font-size: 36px;
      margin-bottom: 16px;
      position: relative;
    }
    h3 {
      font-size: 22px;
    }
    p {
      color: #4A5568;
    }
    a {
      text-decoration: none;
      color: inherit;
    }
    img {
      max-width: 100%;
      display: block;
    }
    button, .btn {
      cursor: pointer;
      font-family: inherit;
      border: none;
      background: transparent;
    }
    .btn-primary {
      background: var(--electric-cyan);
      color: var(--deep-black-blue);
      font-weight: 700;
      padding: 14px 36px;
      border-radius: var(--radius-btn);
      display: inline-flex;
      align-items: center;
      justify-content: center;
      transition: var(--transition);
      border: 2px solid transparent;
      font-size: 16px;
      letter-spacing: 0.5px;
    }
    .btn-primary:hover {
      background: #33F5FF;
      box-shadow: 0 0 20px rgba(0,240,255,0.5);
      transform: translateY(-2px);
    }
    .btn-outline {
      background: white;
      border: 2px solid var(--electric-cyan);
      color: var(--electric-cyan);
      font-weight: 700;
      padding: 12px 34px;
      border-radius: var(--radius-btn);
      transition: var(--transition);
    }
    .btn-outline:hover {
      background: var(--electric-cyan);
      color: var(--deep-black-blue);
      box-shadow: 0 0 18px rgba(0,240,255,0.4);
    }
    .badge {
      background: var(--competition-red);
      color: white;
      font-size: 12px;
      font-weight: 700;
      padding: 4px 12px;
      border-radius: 20px;
      letter-spacing: 0.8px;
      text-transform: uppercase;
    }
    /* 导航 */
    .site-header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      background: white;
      box-shadow: 0 2px 12px rgba(0,0,0,0.04);
      z-index: 1000;
      height: 72px;
      display: flex;
      align-items: center;
    }
    .header-inner {
      display: flex;
      justify-content: space-between;
      align-items: center;
      width: 100%;
    }
    .logo {
      display: flex;
      align-items: baseline;
      gap: 8px;
      font-weight: 800;
      font-size: 24px;
      color: var(--deep-black-blue);
      letter-spacing: 0.5px;
    }
    .logo .domain {
      font-size: 13px;
      font-weight: 400;
      color: #6B7280;
      margin-left: 4px;
      letter-spacing: 0.3px;
    }
    .nav-links {
      display: flex;
      gap: 32px;
      align-items: center;
      font-weight: 500;
    }
    .nav-links a {
      position: relative;
      padding-bottom: 6px;
      transition: color 0.2s;
      font-size: 16px;
      color: var(--text-dark);
    }
    .nav-links a:hover {
      color: var(--electric-cyan);
    }
    .nav-links a::after {
      content: '';
      position: absolute;
      bottom: 0;
      left: 0;
      width: 0;
      height: 2px;
      background: var(--electric-cyan);
      transition: width 0.25s ease;
    }
    .nav-links a:hover::after {
      width: 100%;
    }
    .hamburger {
      display: none;
      flex-direction: column;
      gap: 6px;
      cursor: pointer;
    }
    .hamburger span {
      width: 28px;
      height: 3px;
      background: var(--deep-black-blue);
      border-radius: 4px;
      transition: 0.3s;
    }
    .mobile-menu {
      display: none;
    }
    @media (max-width: 1024px) {
      .nav-links { gap: 20px; }
    }
    @media (max-width: 768px) {
      .nav-links { display: none; }
      .hamburger { display: flex; }
      .mobile-menu {
        position: fixed;
        top: 72px;
        left: 0;
        width: 100%;
        background: rgba(10,14,39,0.96);
        backdrop-filter: blur(12px);
        flex-direction: column;
        padding: 32px;
        gap: 28px;
        z-index: 999;
        display: none;
      }
      .mobile-menu.active {
        display: flex;
      }
      .mobile-menu a {
        color: white;
        font-size: 20px;
        font-weight: 600;
        border-bottom: 1px solid rgba(255,255,255,0.15);
        padding-bottom: 12px;
      }
    }
    /* Hero */
    .hero {
      background-color: var(--deep-black-blue);
      color: white;
      padding: 140px 0 120px;
      margin-top: 72px;
      position: relative;
      overflow: hidden;
      background-image: url('/assets/images/backpic/back-1.webp');
      background-size: cover;
      background-position: center;
    }
    .hero::before {
      content: '';
      position: absolute;
      inset: 0;
      background: rgba(10,14,39,0.55);
      z-index: 0;
    }
    .hero .container {
      position: relative;
      z-index: 2;
      display: flex;
      align-items: center;
      justify-content: space-between;
      gap: 40px;
      flex-wrap: wrap;
    }
    .hero-content {
      max-width: 600px;
    }
    .hero h1 {
      font-size: 52px;
      font-weight: 800;
      margin-bottom: 20px;
      color: white;
      text-shadow: 0 4px 20px rgba(0,0,0,0.4);
    }
    .hero p {
      font-size: 18px;
      color: rgba(255,255,255,0.85);
      margin-bottom: 36px;
      line-height: 1.6;
      max-width: 480px;
    }
    .hero-visual {
      width: 380px;
      height: 280px;
      background: rgba(255,255,255,0.05);
      border-radius: 24px;
      border: 1px solid rgba(0,240,255,0.2);
      backdrop-filter: blur(4px);
      display: flex;
      align-items: center;
      justify-content: center;
    }
    @media (max-width: 768px) {
      .hero { padding: 120px 0 80px; }
      .hero .container { flex-direction: column; text-align: center; }
      .hero h1 { font-size: 38px; }
      .hero-visual { width: 100%; height: 200px; }
    }
    /* 通用板块 */
    section {
      padding: 100px 0;
    }
    .section-title {
      text-align: center;
      margin-bottom: 60px;
    }
    .section-title h2 {
      color: var(--deep-black-blue);
      display: inline-block;
      position: relative;
    }
    .section-title h2::after {
      content: '';
      position: absolute;
      bottom: -12px;
      left: 50%;
      transform: translateX(-50%);
      width: 60px;
      height: 3px;
      background: var(--electric-cyan);
    }
    .grid-3 {
      display: grid;
      grid-template-columns: repeat(3,1fr);
      gap: 24px;
    }
    .card {
      background: var(--card-white);
      border-radius: var(--radius-card);
      padding: 28px;
      box-shadow: var(--shadow-sm);
      transition: var(--transition);
      height: 100%;
    }
    .card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-hover);
    }
    @media (max-width: 1024px) { .grid-3 { grid-template-columns: repeat(2,1fr); } }
    @media (max-width: 640px) { .grid-3 { grid-template-columns: 1fr; } }
    /* 服务卡片 */
    .service-icon {
      font-size: 42px;
      color: var(--electric-cyan);
      margin-bottom: 20px;
    }
    .service-list {
      list-style: none;
      margin-top: 16px;
    }
    .service-list li {
      display: flex;
      align-items: baseline;
      gap: 8px;
      margin-bottom: 10px;
      color: #4B5563;
    }
    .service-list li::before {
      content: "•";
      color: var(--competition-red);
      font-weight: bold;
      font-size: 18px;
    }
    /* 数据区 */
    .stats-section {
      background: var(--deep-black-blue);
      color: white;
    }
    .stats-grid {
      display: grid;
      grid-template-columns: repeat(4,1fr);
      text-align: center;
      gap: 32px;
    }
    .stat-number {
      font-size: 56px;
      font-weight: 800;
      color: var(--electric-cyan);
      line-height: 1.1;
    }
    .stat-label {
      font-size: 18px;
      color: rgba(255,255,255,0.8);
      margin-top: 8px;
    }
    @media (max-width: 768px) { .stats-grid { grid-template-columns: repeat(2,1fr); } }
    /* 案例 */
    .case-img {
      aspect-ratio: 16/9;
      background-size: cover;
      background-position: center;
      border-radius: 12px;
      margin-bottom: 18px;
    }
    .case-tags {
      display: flex;
      gap: 8px;
      margin: 12px 0 8px;
    }
    /* FAQ */
    .faq-item {
      background: white;
      border-radius: 14px;
      margin-bottom: 12px;
      box-shadow: 0 2px 12px rgba(0,0,0,0.04);
      overflow: hidden;
    }
    .faq-question {
      padding: 20px 24px;
      font-weight: 600;
      display: flex;
      justify-content: space-between;
      align-items: center;
      cursor: pointer;
      background: white;
    }
    .faq-toggle {
      font-size: 24px;
      color: var(--electric-cyan);
      transition: 0.2s;
    }
    .faq-answer {
      padding: 0 24px 20px;
      color: #4A5568;
      background: #F9FAFB;
      display: none;
    }
    .faq-item.active .faq-answer {
      display: block;
    }
    /* 联系 */
    .contact-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 48px;
      align-items: start;
    }
    .contact-form input, .contact-form textarea {
      width: 100%;
      padding: 14px 18px;
      border: 1px solid #E2E8F0;
      border-radius: var(--radius-input);
      margin-bottom: 16px;
      font-size: 16px;
      background: white;
    }
    .contact-form input:focus {
      border-color: var(--electric-cyan);
      box-shadow: 0 0 0 3px rgba(0,240,255,0.2);
    }
    @media (max-width: 768px) {
      .contact-grid { grid-template-columns: 1fr; }
      section { padding: 70px 0; }
    }
    footer {
      background: var(--deep-black-blue);
      color: rgba(255,255,255,0.7);
      padding: 48px 0 24px;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr;
      gap: 40px;
      margin-bottom: 32px;
    }
    .copyright {
      border-top: 1px solid rgba(255,255,255,0.15);
      padding-top: 20px;
      text-align: center;
      font-size: 14px;
    }