/* roulang page: index */
:root {
      --deep-blue: #0A0E27;
      --surface-light: #111640;
      --electric: #00C2FF;
      --cyan: #00F5D4;
      --white-70: rgba(255,255,255,0.7);
      --white-50: rgba(255,255,255,0.5);
      --border-glow: rgba(0,194,255,0.15);
      --card-bg: rgba(255,255,255,0.03);
      --radius-lg: 20px;
      --radius-btn: 50px;
      --shadow-card: 0 8px 32px rgba(0,0,0,0.4);
      --glow-hover: 0 0 25px rgba(0,194,255,0.5);
    }
    * {
      box-sizing: border-box;
      margin: 0;
      padding: 0;
    }
    body {
      font-family: 'Inter', 'PingFang SC', 'Microsoft YaHei', sans-serif;
      background-color: var(--deep-blue);
      color: white;
      line-height: 1.6;
      -webkit-font-smoothing: antialiased;
      overflow-x: hidden;
    }
    .glass-card {
      background: var(--card-bg);
      backdrop-filter: blur(20px);
      -webkit-backdrop-filter: blur(20px);
      border: 1px solid var(--border-glow);
      border-radius: var(--radius-lg);
      box-shadow: var(--shadow-card);
    }
    .glass-card:hover {
      box-shadow: var(--glow-hover), var(--shadow-card);
      transform: translateY(-6px);
      transition: all 0.35s ease;
    }
    .btn-primary {
      background: var(--electric);
      color: var(--deep-blue);
      font-weight: 700;
      border-radius: var(--radius-btn);
      padding: 0.9rem 2.4rem;
      border: none;
      cursor: pointer;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      gap: 0.5rem;
      box-shadow: 0 0 15px rgba(0,194,255,0.4);
      transition: all 0.3s ease;
      letter-spacing: 0.5px;
    }
    .btn-primary:hover {
      box-shadow: 0 0 32px #00C2FF;
      transform: scale(1.03);
      background: #33d1ff;
    }
    .btn-outline {
      background: transparent;
      border: 1px solid var(--electric);
      color: var(--electric);
      font-weight: 600;
      border-radius: var(--radius-btn);
      padding: 0.9rem 2.2rem;
      cursor: pointer;
      transition: all 0.3s ease;
    }
    .btn-outline:hover {
      background: rgba(0,194,255,0.12);
      box-shadow: 0 0 18px rgba(0,194,255,0.35);
    }
    .pulse-glow {
      animation: pulse-glow 2.2s infinite;
    }
    @keyframes pulse-glow {
      0% { box-shadow: 0 0 8px #00C2FF; }
      50% { box-shadow: 0 0 28px #00F5D4, 0 0 45px #00C2FF; }
      100% { box-shadow: 0 0 8px #00C2FF; }
    }
    .section-title {
      font-size: 2.5rem;
      font-weight: 700;
      text-align: center;
      margin-bottom: 3rem;
      position: relative;
      display: inline-block;
      left: 50%;
      transform: translateX(-50%);
    }
    .section-title::after {
      content: '';
      position: absolute;
      bottom: -12px;
      left: 50%;
      transform: translateX(-50%);
      width: 70px;
      height: 4px;
      background: linear-gradient(90deg, var(--electric), var(--cyan));
      border-radius: 4px;
    }
    .nav-capsule {
      background: rgba(10,14,39,0.75);
      backdrop-filter: blur(25px);
      -webkit-backdrop-filter: blur(25px);
      border-radius: 60px;
      padding: 0.6rem 2rem;
      border: 1px solid rgba(0,194,255,0.2);
    }
    .mobile-bottom-nav {
      background: rgba(10,14,39,0.85);
      backdrop-filter: blur(30px);
      border-top: 1px solid rgba(0,194,255,0.25);
    }
    @media (max-width: 767px) {
      .section-title {
        font-size: 1.9rem;
      }
    }
    .focus-ring:focus-visible {
      outline: 3px solid var(--cyan);
      outline-offset: 4px;
      border-radius: 8px;
    }
    .grid-bg {
      background-image: radial-gradient(rgba(0,194,255,0.06) 1px, transparent 1px);
      background-size: 28px 28px;
    }