/* roulang page: index */
:root {
      --bg-deep: #0A0E17;
      --bg-card: rgba(15, 25, 45, 0.7);
      --accent-cyan: #00E5FF;
      --accent-orange: #FF6B35;
      --text-white: #FFFFFF;
      --text-body: #B0C4DE;
      --text-muted: #6B7B8D;
      --border-glass: rgba(255, 255, 255, 0.08);
      --radius-card: 16px;
      --radius-btn: 12px;
      --shadow-cyan: 0 0 20px rgba(0, 229, 255, 0.2);
      --shadow-orange: 0 0 25px rgba(255, 107, 53, 0.6);
      --font-sans: 'PingFang SC', 'Microsoft YaHei', 'Noto Sans SC', sans-serif;
      --font-mono: 'Inter', 'SF Pro Display', sans-serif;
    }
    * {
      box-sizing: border-box;
    }
    html {
      scroll-behavior: smooth;
    }
    body {
      margin: 0;
      font-family: var(--font-sans);
      background: radial-gradient(circle at 50% 0%, #1a2535 0%, #0A0E17 70%);
      color: var(--text-body);
      line-height: 1.6;
      -webkit-font-smoothing: antialiased;
    }
    .font-mono {
      font-family: var(--font-mono);
    }
    .glass {
      background: var(--bg-card);
      backdrop-filter: blur(12px);
      -webkit-backdrop-filter: blur(12px);
      border: 1px solid var(--border-glass);
      box-shadow: 0 8px 32px rgba(0, 0, 0, 0.4);
    }
    .glass-light {
      background: rgba(20, 30, 50, 0.5);
      backdrop-filter: blur(6px);
      -webkit-backdrop-filter: blur(6px);
      border: 1px solid rgba(255, 255, 255, 0.06);
    }
    .text-cyan {
      color: var(--accent-cyan);
    }
    .text-orange {
      color: var(--accent-orange);
    }
    .border-cyan {
      border-color: var(--accent-cyan);
    }
    .bg-orange {
      background-color: var(--accent-orange);
    }
    .btn-primary {
      background: var(--accent-orange);
      color: white;
      border-radius: var(--radius-btn);
      padding: 14px 32px;
      font-weight: 600;
      font-size: 1rem;
      border: none;
      cursor: pointer;
      transition: all 0.3s ease;
      box-shadow: 0 4px 15px rgba(255, 107, 53, 0.4);
      display: inline-block;
      text-align: center;
      text-decoration: none;
    }
    .btn-primary:hover {
      box-shadow: var(--shadow-orange);
      transform: translateY(-2px);
      animation: pulse-glow 1.8s infinite;
    }
    .btn-secondary {
      background: transparent;
      color: var(--accent-cyan);
      border: 1px solid var(--accent-cyan);
      border-radius: var(--radius-btn);
      padding: 12px 28px;
      font-weight: 600;
      font-size: 0.95rem;
      cursor: pointer;
      transition: all 0.3s ease;
      text-decoration: none;
      display: inline-block;
    }
    .btn-secondary:hover {
      background: rgba(0, 229, 255, 0.1);
      border-color: white;
      color: white;
    }
    @keyframes pulse-glow {
      0% { box-shadow: 0 0 15px rgba(255, 107, 53, 0.5); }
      50% { box-shadow: 0 0 35px rgba(255, 107, 53, 0.8); }
      100% { box-shadow: 0 0 15px rgba(255, 107, 53, 0.5); }
    }
    .card-hover {
      transition: transform 0.3s ease, border-color 0.3s ease, box-shadow 0.3s ease;
    }
    .card-hover:hover {
      transform: translateY(-6px);
      border-color: rgba(0, 229, 255, 0.35);
      box-shadow: var(--shadow-cyan);
    }
    .nav-link {
      color: var(--text-body);
      transition: color 0.2s;
      text-decoration: none;
      position: relative;
    }
    .nav-link:hover,
    .nav-link.active {
      color: var(--accent-cyan);
    }
    .nav-link.active::after {
      content: '';
      position: absolute;
      bottom: -6px;
      left: 0;
      width: 100%;
      height: 2px;
      background: var(--accent-cyan);
    }
    .hamburger-line {
      display: block;
      width: 24px;
      height: 2px;
      background: var(--accent-cyan);
      margin: 5px 0;
      transition: 0.3s;
    }
    .menu-open .hamburger-line:nth-child(1) { transform: rotate(45deg) translate(5px,5px); }
    .menu-open .hamburger-line:nth-child(2) { opacity: 0; }
    .menu-open .hamburger-line:nth-child(3) { transform: rotate(-45deg) translate(5px,-5px); }
    .mobile-menu {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.4s ease;
      background: rgba(10,14,23,0.95);
      backdrop-filter: blur(20px);
    }
    .mobile-menu.open {
      max-height: 400px;
    }
    .count-up {
      font-variant-numeric: tabular-nums;
      font-weight: 800;
      color: var(--accent-cyan);
      font-family: var(--font-mono);
    }
    details summary {
      list-style: none;
      cursor: pointer;
      display: flex;
      justify-content: space-between;
      align-items: center;
      color: white;
      font-weight: 600;
      font-size: 1.1rem;
    }
    details summary::-webkit-details-marker { display: none; }
    details[open] summary .arrow-icon { transform: rotate(180deg); }
    .arrow-icon {
      transition: transform 0.3s ease;
      color: var(--accent-cyan);
      font-size: 1.2rem;
    }
    .testimonial-scroll {
      scroll-snap-type: x mandatory;
      -webkit-overflow-scrolling: touch;
    }
    .testimonial-scroll > div {
      scroll-snap-align: start;
      flex-shrink: 0;
      width: 80%;
      max-width: 360px;
    }
    @media (min-width: 768px) {
      .testimonial-scroll > div {
        width: 45%;
      }
    }
    @media (min-width: 1024px) {
      .testimonial-scroll > div {
        width: 30%;
      }
    }