/* roulang page: index */
:root {
      --primary: #0A0E27;
      --accent: #00E5FF;
      --highlight: #FF6B35;
      --surface-glass: rgba(255,255,255,0.03);
      --surface-elevated: #111640;
      --border-subtle: rgba(255,255,255,0.08);
      --text-primary: #FFFFFF;
      --text-body: rgba(255,255,255,0.75);
      --text-muted: rgba(255,255,255,0.5);
      --radius-sm: 12px;
      --radius-md: 16px;
      --radius-pill: 50px;
      --shadow-card: 0 8px 32px rgba(0,0,0,0.4);
      --shadow-glow-cyan: 0 0 20px rgba(0,229,255,0.4);
      --shadow-glow-orange: 0 0 20px rgba(255,107,53,0.4);
      --font-sans: 'Inter', 'PingFang SC', 'Microsoft YaHei', -apple-system, sans-serif;
      --spacing-section: 120px;
      --container-max: 1200px;
    }
    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }
    html {
      scroll-behavior: smooth;
    }
    body {
      font-family: var(--font-sans);
      background-color: var(--primary);
      color: var(--text-body);
      line-height: 1.7;
      font-size: 16px;
      font-weight: 400;
      min-height: 100vh;
      -webkit-font-smoothing: antialiased;
    }
    img {
      max-width: 100%;
      height: auto;
      display: block;
    }
    a {
      text-decoration: none;
      color: inherit;
      transition: color 0.2s ease;
    }
    button, .btn {
      cursor: pointer;
      font-family: inherit;
      border: none;
      background: none;
    }
    .container {
      max-width: var(--container-max);
      margin: 0 auto;
      padding: 0 24px;
      width: 100%;
    }
    /* 玻璃拟态卡片 */
    .glass-card {
      background: var(--surface-glass);
      backdrop-filter: blur(20px);
      -webkit-backdrop-filter: blur(20px);
      border: 1px solid var(--border-subtle);
      border-radius: var(--radius-md);
      box-shadow: var(--shadow-card);
      transition: transform 0.25s ease, box-shadow 0.3s ease, border-color 0.2s, background 0.2s;
    }
    .glass-card:hover {
      transform: translateY(-8px);
      box-shadow: 0 16px 48px rgba(0,229,255,0.15);
      border-color: rgba(0,229,255,0.3);
      background: rgba(255,255,255,0.06);
    }
    .glass-card-sm {
      background: var(--surface-glass);
      backdrop-filter: blur(15px);
      -webkit-backdrop-filter: blur(15px);
      border: 1px solid var(--border-subtle);
      border-radius: var(--radius-sm);
    }
    /* 按钮 */
    .btn-primary {
      background: var(--accent);
      color: var(--primary);
      font-weight: 600;
      padding: 14px 32px;
      border-radius: var(--radius-pill);
      box-shadow: var(--shadow-glow-cyan);
      display: inline-flex;
      align-items: center;
      justify-content: center;
      transition: all 0.25s ease;
      letter-spacing: 0.3px;
    }
    .btn-primary:hover {
      background: #33EAFF;
      box-shadow: 0 0 32px rgba(0,229,255,0.6);
      transform: translateY(-2px);
      color: var(--primary);
    }
    .btn-outline {
      background: transparent;
      border: 1px solid rgba(0,229,255,0.5);
      color: var(--accent);
      font-weight: 600;
      padding: 14px 32px;
      border-radius: var(--radius-pill);
      display: inline-flex;
      align-items: center;
      justify-content: center;
      transition: all 0.25s ease;
    }
    .btn-outline:hover {
      background: rgba(0,229,255,0.1);
      border-color: var(--accent);
      color: var(--accent);
      transform: translateY(-2px);
    }
    .btn-highlight {
      background: var(--highlight);
      color: #FFFFFF;
      font-weight: 700;
      padding: 16px 40px;
      border-radius: var(--radius-pill);
      box-shadow: var(--shadow-glow-orange);
      display: inline-flex;
      align-items: center;
      justify-content: center;
      transition: all 0.25s ease;
      letter-spacing: 0.5px;
    }
    .btn-highlight:hover {
      background: #FF8055;
      box-shadow: 0 0 28px rgba(255,107,53,0.7);
      transform: translateY(-2px);
      color: #fff;
    }
    .btn-sm {
      padding: 8px 20px;
      font-size: 14px;
    }
    /* 导航 */
    #nav {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      z-index: 50;
      background: transparent;
      transition: background 0.3s ease, backdrop-filter 0.3s, box-shadow 0.3s;
      padding: 16px 0;
    }
    #nav.scrolled {
      background: rgba(10,14,39,0.85);
      backdrop-filter: blur(20px);
      -webkit-backdrop-filter: blur(20px);
      box-shadow: 0 4px 20px rgba(0,0,0,0.3);
      border-bottom: 1px solid rgba(255,255,255,0.06);
    }
    .nav-container {
      display: flex;
      align-items: center;
      justify-content: space-between;
      max-width: var(--container-max);
      margin: 0 auto;
      padding: 0 24px;
    }
    .logo {
      font-weight: 800;
      font-size: 24px;
      letter-spacing: -0.3px;
      background: linear-gradient(135deg, #00E5FF 0%, #7BDAFF 100%);
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
      background-clip: text;
    }
    .nav-links {
      display: flex;
      gap: 36px;
      align-items: center;
    }
    .nav-links a {
      font-size: 14px;
      font-weight: 500;
      color: var(--text-primary);
      transition: color 0.2s;
      position: relative;
    }
    .nav-links a:hover,
    .nav-links a.active {
      color: var(--accent);
    }
    .nav-links a.active::after {
      content: '';
      position: absolute;
      bottom: -6px;
      left: 0;
      width: 100%;
      height: 2px;
      background: var(--accent);
      box-shadow: 0 0 8px var(--accent);
    }
    .hamburger {
      display: none;
      flex-direction: column;
      gap: 5px;
      cursor: pointer;
    }
    .hamburger span {
      width: 24px;
      height: 2px;
      background: white;
      transition: 0.3s;
    }
    .mobile-menu {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 100vh;
      background: var(--primary);
      display: flex;
      flex-direction: column;
      justify-content: center;
      align-items: center;
      gap: 28px;
      transform: translateX(100%);
      transition: transform 0.35s ease;
      z-index: 45;
    }
    .mobile-menu.active {
      transform: translateX(0);
    }
    .mobile-menu a {
      font-size: 20px;
      color: white;
      font-weight: 600;
    }
    /* Hero */
    #hero {
      padding: 160px 0 100px;
      position: relative;
      background: var(--primary);
      overflow: hidden;
    }
    .hero-grid {
      display: flex;
      align-items: center;
      gap: 60px;
    }
    .hero-left {
      flex: 1;
    }
    .hero-right {
      flex: 1;
      display: flex;
      justify-content: center;
    }
    .hero-badge {
      display: inline-block;
      border: 1px solid var(--accent);
      color: var(--accent);
      padding: 6px 18px;
      border-radius: 50px;
      font-size: 14px;
      font-weight: 500;
      margin-bottom: 24px;
    }
    h1 {
      font-size: 56px;
      font-weight: 800;
      line-height: 1.15;
      letter-spacing: -0.02em;
      color: var(--text-primary);
      margin-bottom: 24px;
    }
    .hero-sub {
      font-size: 16px;
      color: var(--text-body);
      margin-bottom: 36px;
      max-width: 480px;
    }
    .hero-buttons {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
    }
    .hero-visual {
      width: 100%;
      max-width: 500px;
      aspect-ratio: 1/1;
      background: radial-gradient(circle at 30% 40%, rgba(0,229,255,0.15) 0%, transparent 60%);
      border-radius: 32px;
      display: flex;
      align-items: center;
      justify-content: center;
      position: relative;
    }
    .hero-visual img {
      border-radius: 24px;
      object-fit: cover;
      width: 100%;
      height: auto;
    }
    .particle {
      position: absolute;
      background: var(--accent);
      border-radius: 50%;
      opacity: 0.5;
      animation: float 6s infinite alternate;
    }
    @keyframes float {
      0% { transform: translateY(0px); }
      100% { transform: translateY(-20px); }
    }
    /* 区块标题 */
    .section-title {
      font-size: 42px;
      font-weight: 700;
      color: var(--text-primary);
      margin-bottom: 16px;
      line-height: 1.2;
    }
    .section-sub {
      color: var(--text-muted);
      max-width: 650px;
      margin: 0 auto 48px;
    }
    .section-pad {
      padding: var(--spacing-section) 0;
    }
    /* 网格 */
    .grid-3 {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }
    .grid-2 {
      display: grid;
      grid-template-columns: repeat(2, 1fr);
      gap: 24px;
    }
    .advantage-card {
      padding: 32px;
      text-align: center;
    }
    .icon-wrap {
      font-size: 40px;
      margin-bottom: 20px;
      color: var(--accent);
    }
    .service-card {
      padding: 32px;
      display: flex;
      flex-direction: column;
      height: 100%;
    }
    .service-link {
      margin-top: auto;
      color: var(--accent);
      font-weight: 500;
      display: inline-block;
      transition: transform 0.2s;
    }
    .service-link:hover {
      transform: translateX(4px);
    }
    .scenario-card {
      border-radius: var(--radius-md);
      overflow: hidden;
      background: var(--surface-glass);
      backdrop-filter: blur(15px);
      border: 1px solid var(--border-subtle);
    }
    .scenario-img {
      height: 200px;
      background-size: cover;
      background-position: center;
    }
    .scenario-content {
      padding: 24px;
    }
    .cases-layout {
      display: grid;
      grid-template-columns: 1fr 1.5fr;
      gap: 40px;
      align-items: start;
    }
    .big-number {
      font-size: 48px;
      font-weight: 800;
      color: var(--highlight);
      line-height: 1.1;
    }
    .case-card {
      background: var(--surface-glass);
      backdrop-filter: blur(15px);
      border-radius: var(--radius-md);
      border: 1px solid var(--border-subtle);
      overflow: hidden;
    }
    .faq-item {
      margin-bottom: 12px;
    }
    .faq-header {
      background: rgba(255,255,255,0.03);
      border-radius: var(--radius-sm);
      padding: 20px 24px;
      display: flex;
      justify-content: space-between;
      align-items: center;
      cursor: pointer;
      font-weight: 600;
      color: white;
    }
    .faq-body {
      padding: 0 24px 20px;
      display: none;
      color: var(--text-body);
    }
    .faq-item.open .faq-body {
      display: block;
    }
    .faq-item.open .faq-header {
      border-bottom: 2px solid var(--accent);
    }
    #cta {
      background: var(--surface-elevated);
      padding: 100px 0;
      text-align: center;
      position: relative;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 40px;
    }
    .footer-bottom {
      border-top: 1px solid var(--border-subtle);
      margin-top: 40px;
      padding-top: 24px;
      text-align: center;
      color: rgba(255,255,255,0.4);
    }
    @media (max-width: 1023px) {
      .grid-3 { grid-template-columns: repeat(2, 1fr); }
      .hero-grid { flex-direction: column; }
      .cases-layout { grid-template-columns: 1fr; }
      .footer-grid { grid-template-columns: repeat(2, 1fr); }
      h1 { font-size: 42px; }
      .section-title { font-size: 32px; }
    }
    @media (max-width: 767px) {
      .grid-3, .grid-2 { grid-template-columns: 1fr; }
      .nav-links { display: none; }
      .hamburger { display: flex; }
      .hero-buttons { flex-direction: column; align-items: flex-start; }
      .section-pad { padding: 60px 0; }
      h1 { font-size: 36px; }
      .section-title { font-size: 28px; }
    }