/* roulang page: index */
:root {
      --primary-cyan: #00E5FF;
      --deep-purple: #1A1F3A;
      --accent-orange: #FF6B35;
      --bg-light: #F4F6FA;
      --text-white: #FFFFFF;
      --text-light-gray: #B0C4DE;
      --text-dark: #1A1F3A;
      --text-muted: #5A6070;
      --border-glass: rgba(255,255,255,0.1);
      --shadow-card: 0 4px 20px rgba(0,0,0,0.06);
      --shadow-hover: 0 12px 32px rgba(0,0,0,0.12);
      --radius-card: 16px;
      --radius-button: 50px;
      --radius-input: 8px;
      --radius-block: 24px;
      --font-sans: 'Inter', 'PingFang SC', 'Microsoft YaHei', 'Hiragino Sans GB', sans-serif;
      --transition-smooth: all 0.3s ease;
    }
    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }
    body {
      font-family: var(--font-sans);
      background-color: var(--deep-purple);
      color: var(--text-white);
      line-height: 1.7;
      overflow-x: hidden;
    }
    .container {
      max-width: 1200px;
      margin: 0 auto;
      padding: 0 24px;
    }
    /* 导航区 */
    .navbar {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 72px;
      background: rgba(26, 31, 58, 0.85);
      backdrop-filter: blur(12px);
      display: flex;
      align-items: center;
      justify-content: space-between;
      padding: 0 32px;
      z-index: 1000;
      border-bottom: 1px solid var(--border-glass);
      transition: var(--transition-smooth);
    }
    .logo {
      display: flex;
      align-items: center;
      gap: 8px;
      font-size: 24px;
      font-weight: 700;
      color: var(--text-white);
      text-decoration: none;
    }
    .logo-icon {
      font-size: 28px;
      color: var(--primary-cyan);
    }
    .nav-links {
      display: flex;
      align-items: center;
      gap: 32px;
      list-style: none;
    }
    .nav-links a {
      color: var(--text-light-gray);
      text-decoration: none;
      font-size: 16px;
      position: relative;
      padding: 4px 0;
      transition: color 0.2s;
    }
    .nav-links a::after {
      content: '';
      position: absolute;
      bottom: -2px;
      left: 50%;
      width: 0;
      height: 2px;
      background: var(--primary-cyan);
      transition: width 0.3s ease, left 0.3s ease;
    }
    .nav-links a:hover {
      color: var(--primary-cyan);
    }
    .nav-links a:hover::after {
      width: 100%;
      left: 0;
    }
    .btn-cta {
      background: var(--accent-orange);
      color: white;
      padding: 10px 24px;
      border-radius: var(--radius-button);
      font-weight: 600;
      text-decoration: none;
      transition: box-shadow 0.3s, transform 0.2s;
      box-shadow: 0 4px 15px rgba(255,107,53,0.3);
      white-space: nowrap;
    }
    .btn-cta:hover {
      box-shadow: 0 8px 25px rgba(255,107,53,0.5);
      transform: translateY(-1px);
    }
    .menu-toggle {
      display: none;
      background: none;
      border: none;
      color: white;
      font-size: 28px;
      cursor: pointer;
    }
    .mobile-menu {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 100vh;
      background: rgba(26,31,58,0.98);
      backdrop-filter: blur(20px);
      display: flex;
      flex-direction: column;
      justify-content: center;
      align-items: flex-start;
      padding: 48px 32px;
      transform: translateX(100%);
      transition: transform 0.35s ease;
      z-index: 999;
    }
    .mobile-menu.open {
      transform: translateX(0);
    }
    .mobile-menu a {
      color: white;
      font-size: 24px;
      margin: 20px 0;
      text-decoration: none;
    }
    .close-menu {
      position: absolute;
      top: 24px;
      right: 32px;
      background: none;
      border: none;
      color: white;
      font-size: 36px;
      cursor: pointer;
    }
    /* 首屏 */
    .hero {
      min-height: 100vh;
      display: flex;
      align-items: center;
      background: radial-gradient(circle at 20% 30%, #2a2f4a, var(--deep-purple) 80%);
      position: relative;
      overflow: hidden;
    }
    .hero-content {
      display: flex;
      align-items: center;
      justify-content: space-between;
      gap: 48px;
      width: 100%;
    }
    .hero-text {
      flex: 1;
    }
    .hero h1 {
      font-size: 48px;
      font-weight: 700;
      line-height: 1.2;
      margin-bottom: 20px;
    }
    .hero .subtitle {
      font-size: 18px;
      color: var(--text-light-gray);
      margin-bottom: 32px;
    }
    .hero-buttons {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
    }
    .btn-primary {
      background: var(--primary-cyan);
      color: var(--deep-purple);
      padding: 14px 32px;
      border-radius: var(--radius-button);
      font-weight: 700;
      text-decoration: none;
      box-shadow: 0 0 20px rgba(0,229,255,0.5);
      transition: box-shadow 0.3s, transform 0.2s;
    }
    .btn-primary:hover {
      box-shadow: 0 0 35px rgba(0,229,255,0.8);
      transform: translateY(-2px);
    }
    .btn-outline {
      background: transparent;
      border: 1px solid var(--primary-cyan);
      color: var(--primary-cyan);
      padding: 14px 32px;
      border-radius: var(--radius-button);
      font-weight: 600;
      text-decoration: none;
      transition: background 0.2s;
    }
    .btn-outline:hover {
      background: rgba(0,229,255,0.15);
    }
    .hero-image img {
      max-width: 500px;
      border-radius: 24px;
      box-shadow: 0 0 40px rgba(0,229,255,0.25);
    }
    .scroll-down {
      position: absolute;
      bottom: 24px;
      left: 50%;
      transform: translateX(-50%);
      color: var(--primary-cyan);
      font-size: 28px;
      animation: bounce 2s infinite;
    }
    @keyframes bounce {
      0%,100%{transform:translateX(-50%) translateY(0);}
      50%{transform:translateX(-50%) translateY(10px);}
    }
    section {
      padding: 100px 0;
    }
    .section-title {
      font-size: 36px;
      font-weight: 700;
      margin-bottom: 16px;
      text-align: center;
    }
    .section-desc {
      color: var(--text-light-gray);
      text-align: center;
      max-width: 700px;
      margin: 0 auto 48px;
    }
    .bg-light-section {
      background-color: var(--bg-light);
      color: var(--text-dark);
    }
    /* 核心优势 1大2小 */
    .features-grid {
      display: grid;
      grid-template-columns: 1.5fr 1fr;
      gap: 24px;
      align-items: stretch;
    }
    .feature-large {
      background: rgba(255,255,255,0.06);
      backdrop-filter: blur(10px);
      border: 1px solid var(--border-glass);
      border-radius: var(--radius-card);
      padding: 32px;
      transition: var(--transition-smooth);
      grid-row: span 2;
    }
    .feature-small-group {
      display: flex;
      flex-direction: column;
      gap: 24px;
    }
    .feature-card {
      background: rgba(255,255,255,0.06);
      backdrop-filter: blur(10px);
      border: 1px solid var(--border-glass);
      border-radius: var(--radius-card);
      padding: 24px;
      transition: var(--transition-smooth);
    }
    .feature-card:hover, .feature-large:hover {
      transform: translateY(-5px);
      border-color: var(--primary-cyan);
      box-shadow: 0 0 24px rgba(0,229,255,0.15);
    }
    .service-scroll {
      display: flex;
      gap: 24px;
      overflow-x: auto;
      padding-bottom: 16px;
      scroll-snap-type: x mandatory;
    }
    .service-card {
      min-width: 260px;
      background: white;
      border-radius: var(--radius-card);
      overflow: hidden;
      box-shadow: var(--shadow-card);
      scroll-snap-align: start;
      transition: var(--transition-smooth);
    }
    .service-card:hover {
      transform: translateY(-6px);
      box-shadow: var(--shadow-hover);
    }
    .service-card img {
      width: 100%;
      height: 160px;
      object-fit: cover;
    }
    .accordion-item {
      border-bottom: 1px solid rgba(0,0,0,0.08);
    }
    .accordion-header {
      padding: 20px;
      font-weight: 600;
      cursor: pointer;
      display: flex;
      justify-content: space-between;
    }
    .footer {
      background: var(--deep-purple);
      padding: 60px 0 30px;
    }
    @media (max-width: 768px) {
      .navbar { padding: 0 20px; }
      .nav-links { display: none; }
      .menu-toggle { display: block; }
      .hero-content { flex-direction: column; text-align: center; }
      .hero h1 { font-size: 36px; }
      .features-grid { grid-template-columns: 1fr; }
      .footer-grid { grid-template-columns: 1fr; }
    }