/* roulang page: index */
:root {
      --deep-midnight: #0A0E1A;
      --electric-cyan: #00E5FF;
      --competitive-purple: #7B2FFF;
      --surface-white: #FFFFFF;
      --surface-light: #F5F6FA;
      --text-primary: #1A1A2E;
      --text-secondary: #6B7280;
      --border-light: #E5E7EB;
      --data-green: #00F0A8;
      --warning-orange: #FF6B4A;
      --radius-card: 12px;
      --radius-btn: 8px;
      --radius-input: 6px;
      --shadow-sm: 0 1px 3px rgba(0,0,0,0.06), 0 1px 2px rgba(0,0,0,0.04);
      --shadow-hover: 0 10px 25px rgba(0,0,0,0.08);
      --font-system: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", "Helvetica Neue", sans-serif;
      --transition-smooth: 0.25s ease;
    }

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

    body {
      font-family: var(--font-system);
      background-color: var(--surface-light);
      color: var(--text-primary);
      line-height: 1.7;
      -webkit-font-smoothing: antialiased;
      -moz-osx-font-smoothing: grayscale;
    }

    .container {
      max-width: 1280px;
      margin: 0 auto;
      padding: 0 32px;
    }

    a {
      text-decoration: none;
      color: inherit;
      transition: var(--transition-smooth);
    }

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

    button, input, textarea {
      font-family: inherit;
      border: none;
      outline: none;
      background: transparent;
    }

    /* 导航 */
    .header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      z-index: 1000;
      transition: background 0.3s ease, box-shadow 0.3s ease;
      backdrop-filter: blur(12px);
      background: rgba(10, 14, 26, 0.75);
    }

    .header.scrolled {
      background: rgba(10, 14, 26, 0.92);
      box-shadow: 0 4px 20px rgba(0,0,0,0.3);
    }

    .nav-bar {
      display: flex;
      align-items: center;
      justify-content: space-between;
      height: 72px;
      padding: 0 32px;
    }

    .logo {
      font-size: 22px;
      font-weight: 700;
      color: var(--electric-cyan);
      letter-spacing: 0.5px;
      white-space: nowrap;
    }

    .nav-menu {
      display: flex;
      align-items: center;
      gap: 40px;
      list-style: none;
    }

    .nav-menu a {
      color: #CCD0D8;
      font-size: 15px;
      font-weight: 500;
      position: relative;
      padding: 4px 0;
    }

    .nav-menu a.active, .nav-menu a:hover {
      color: var(--electric-cyan);
    }

    .nav-menu a.active::after {
      content: '';
      position: absolute;
      bottom: -4px;
      left: 0;
      width: 100%;
      height: 2px;
      background: var(--electric-cyan);
    }

    .nav-cta {
      background: var(--electric-cyan);
      color: var(--deep-midnight) !important;
      padding: 10px 24px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      transition: var(--transition-smooth);
      display: inline-block;
    }

    .nav-cta:hover {
      background: #00C8E0;
      transform: scale(1.03);
    }

    .hamburger {
      display: none;
      flex-direction: column;
      justify-content: space-between;
      width: 28px;
      height: 20px;
      cursor: pointer;
      background: transparent;
    }

    .hamburger span {
      width: 100%;
      height: 2px;
      background: #ffffff;
      transition: 0.3s;
    }

    .mobile-menu {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 100vh;
      background: var(--deep-midnight);
      display: none;
      flex-direction: column;
      align-items: center;
      justify-content: center;
      z-index: 999;
      gap: 28px;
      font-size: 24px;
    }

    .mobile-menu.active {
      display: flex;
    }

    .mobile-close {
      position: absolute;
      top: 24px;
      right: 32px;
      font-size: 36px;
      color: white;
      cursor: pointer;
      background: none;
    }

    /* 区块通用 */
    section {
      padding: 100px 0;
    }

    .section-title {
      font-size: 38px;
      font-weight: 600;
      color: var(--text-primary);
      margin-bottom: 16px;
      position: relative;
      display: inline-block;
    }

    .section-title::after {
      content: '';
      display: block;
      width: 60px;
      height: 4px;
      background: var(--electric-cyan);
      margin-top: 8px;
    }

    .btn-primary {
      background: var(--electric-cyan);
      color: var(--deep-midnight);
      font-weight: 600;
      padding: 14px 32px;
      border-radius: var(--radius-btn);
      display: inline-block;
      transition: var(--transition-smooth);
      cursor: pointer;
    }

    .btn-primary:hover {
      background: #00C8E0;
      transform: scale(1.03);
    }

    .btn-outline {
      background: transparent;
      border: 1.5px solid var(--electric-cyan);
      color: var(--electric-cyan);
      font-weight: 600;
      padding: 12px 28px;
      border-radius: var(--radius-btn);
      transition: var(--transition-smooth);
      cursor: pointer;
    }

    .btn-outline:hover {
      background: rgba(0,229,255,0.1);
    }

    /* Hero */
    .hero {
      min-height: 100vh;
      display: flex;
      align-items: center;
      background-color: var(--deep-midnight);
      background-image: url('/assets/images/backpic/back-1.webp');
      background-size: cover;
      background-position: center;
      position: relative;
      color: white;
      padding: 0;
    }

    .hero .container {
      display: flex;
      align-items: center;
      gap: 60px;
      flex-wrap: wrap;
    }

    .hero-text {
      flex: 1;
    }

    .hero h1 {
      font-size: 52px;
      font-weight: 700;
      line-height: 1.15;
      margin-bottom: 24px;
    }

    .hero p {
      font-size: 18px;
      color: #ccc;
      margin-bottom: 32px;
      max-width: 500px;
    }

    .hero-visual {
      flex: 1;
      min-width: 280px;
    }

    .data-flow {
      width: 100%;
      height: 300px;
      background: radial-gradient(circle at 30% 40%, rgba(0,229,255,0.15) 0%, transparent 70%);
      border-radius: 20px;
      display: flex;
      align-items: center;
      justify-content: center;
    }

    /* 服务卡片 */
    .services-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 32px;
      margin-top: 48px;
    }

    .service-card {
      background: var(--surface-white);
      border-radius: var(--radius-card);
      padding: 32px;
      box-shadow: var(--shadow-sm);
      transition: var(--transition-smooth);
    }

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

    .service-icon {
      font-size: 36px;
      margin-bottom: 16px;
    }

    /* 优势区 */
    .advantages-wrapper {
      display: flex;
      gap: 80px;
      align-items: center;
      margin-top: 48px;
    }

    .big-stat {
      font-size: 96px;
      font-weight: 300;
      color: var(--electric-cyan);
      line-height: 1;
    }

    .advantage-list {
      display: flex;
      flex-direction: column;
      gap: 24px;
    }

    /* 案例卡片 */
    .cases-grid {
      display: grid;
      grid-template-columns: repeat(2, 1fr);
      gap: 32px;
      margin-top: 48px;
    }

    .case-card {
      border: 1px solid var(--border-light);
      border-radius: var(--radius-card);
      padding: 24px;
      transition: var(--transition-smooth);
    }

    .case-card:hover {
      border-color: var(--electric-cyan);
    }

    /* FAQ */
    .faq-list {
      max-width: 800px;
      margin: 48px auto 0;
    }

    .faq-item {
      border-bottom: 1px solid var(--border-light);
      padding: 20px 0;
      cursor: pointer;
    }

    .faq-question {
      font-weight: 500;
      font-size: 18px;
      display: flex;
      justify-content: space-between;
    }

    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.35s ease;
      color: var(--text-secondary);
    }

    /* CTA 深色块 */
    .cta-block {
      background: linear-gradient(135deg, #0A0E1A 0%, #1A1F33 100%);
      text-align: center;
      padding: 80px 0;
      color: white;
    }

    /* 联系表单 */
    .contact-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 48px;
      margin-top: 48px;
    }

    .input-field {
      width: 100%;
      padding: 12px 0;
      border-bottom: 1px solid var(--border-light);
      margin-bottom: 24px;
      transition: 0.2s;
    }

    .input-field:focus {
      border-bottom-color: var(--electric-cyan);
    }

    .btn-submit {
      background: var(--competitive-purple);
      color: white;
      padding: 14px 32px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      cursor: pointer;
    }

    footer {
      background: #0A0E1A;
      color: #aaa;
      padding: 40px 0;
      text-align: center;
    }

    @media (max-width: 1024px) {
      .nav-menu { display: none; }
      .hamburger { display: flex; }
      .hero h1 { font-size: 38px; }
      .advantages-wrapper { flex-direction: column; }
      .big-stat { font-size: 64px; }
    }

    @media (max-width: 768px) {
      .container { padding: 0 24px; }
      .services-grid, .cases-grid { grid-template-columns: 1fr; }
      .contact-grid { grid-template-columns: 1fr; }
      .hero .container { flex-direction: column; }
    }