/* roulang page: index */
:root {
      --primary: #00E676;
      --primary-dark: #00C853;
      --secondary-bg: #0A1128;
      --secondary-light: #1A2340;
      --accent: #FF9100;
      --text-on-dark: #FFFFFF;
      --text-muted: #B0BEC5;
      --text-dark: #263238;
      --glass-bg: rgba(255,255,255,0.03);
      --glass-border: rgba(255,255,255,0.08);
      --card-shadow: 0 4px 20px rgba(0,0,0,0.2);
      --card-hover-shadow: 0 8px 30px rgba(0,230,118,0.15);
      --btn-radius: 50px;
      --card-radius: 16px;
      --section-padding: 100px 0;
      --nav-height: 72px;
    }

    * {
      box-sizing: border-box;
    }

    body {
      font-family: 'PingFang SC', 'Microsoft YaHei', 'Noto Sans SC', 'Inter', 'Roboto', sans-serif;
      background-color: var(--secondary-bg);
      color: var(--text-on-dark);
      line-height: 1.6;
      margin: 0;
      padding: 0;
      overflow-x: hidden;
    }

    h1, h2, h3, h4, h5, h6 {
      font-weight: 700;
      line-height: 1.3;
    }

    h1 {
      font-size: 48px;
      letter-spacing: -0.5px;
    }

    h2 {
      font-size: 36px;
    }

    h3 {
      font-size: 24px;
      font-weight: 600;
    }

    p {
      font-size: 16px;
      line-height: 28px;
      font-weight: 400;
      color: var(--text-muted);
    }

    .text-small {
      font-size: 14px;
      line-height: 20px;
    }

    a {
      text-decoration: none;
      color: inherit;
      transition: color 0.2s;
    }

    .btn {
      font-weight: 600;
      font-size: 16px;
      letter-spacing: 0.5px;
      padding: 12px 28px;
      border-radius: var(--btn-radius);
      transition: all 0.3s ease;
    }

    .btn-primary-custom {
      background-color: var(--primary);
      border: none;
      color: var(--secondary-bg);
      box-shadow: 0 0 15px rgba(0,230,118,0.5);
    }

    .btn-primary-custom:hover, .btn-primary-custom:focus-visible {
      background-color: var(--primary-dark);
      box-shadow: 0 0 25px rgba(0,230,118,0.7);
      color: var(--secondary-bg);
      outline: none;
    }

    .btn-outline-custom {
      background: transparent;
      border: 1.5px solid var(--primary);
      color: var(--primary);
    }

    .btn-outline-custom:hover, .btn-outline-custom:focus-visible {
      background-color: rgba(0,230,118,0.1);
      border-color: var(--primary-dark);
      color: var(--primary-dark);
      outline: none;
    }

    .glass-card {
      background: rgba(26,35,64,0.6);
      backdrop-filter: blur(12px);
      border: 1px solid var(--glass-border);
      border-radius: var(--card-radius);
      box-shadow: var(--card-shadow);
      transition: transform 0.3s ease, box-shadow 0.3s ease;
    }

    .glass-card:hover {
      transform: translateY(-4px);
      box-shadow: var(--card-hover-shadow);
      border-color: rgba(0,230,118,0.25);
    }

    .nav-glass {
      background: rgba(10,17,40,0.85);
      backdrop-filter: blur(20px);
      border-bottom: 1px solid rgba(255,255,255,0.05);
      height: var(--nav-height);
      box-shadow: 0 4px 12px rgba(0,0,0,0.1);
    }

    .navbar-brand img {
      height: 40px;
      width: auto;
    }

    .nav-link {
      color: var(--text-muted) !important;
      font-weight: 500;
      padding: 0.5rem 1rem;
      transition: color 0.2s;
      position: relative;
    }

    .nav-link:hover, .nav-link.active {
      color: var(--primary) !important;
    }

    .nav-link.active::after {
      content: '';
      position: absolute;
      bottom: 0;
      left: 1rem;
      right: 1rem;
      height: 2px;
      background: var(--primary);
      box-shadow: 0 0 8px rgba(0,230,118,0.6);
    }

    .search-box {
      background: rgba(255,255,255,0.05);
      border: 1px solid rgba(255,255,255,0.1);
      border-radius: 50px;
      padding: 6px 16px;
      color: white;
      transition: 0.2s;
    }

    .search-box input {
      background: transparent;
      border: none;
      color: white;
      outline: none;
      width: 120px;
    }

    .search-box i {
      color: var(--text-muted);
    }

    .pulse-btn {
      animation: pulse 2s infinite;
    }

    @keyframes pulse {
      0% { box-shadow: 0 0 15px rgba(0,230,118,0.5); }
      50% { box-shadow: 0 0 25px rgba(0,230,118,0.9); }
      100% { box-shadow: 0 0 15px rgba(0,230,118,0.5); }
    }

    .hero-section {
      min-height: 100vh;
      background: linear-gradient(135deg, #0A1128 0%, #1A2340 70%);
      position: relative;
      display: flex;
      align-items: center;
      overflow: hidden;
    }

    .hero-overlay {
      position: absolute;
      top: 0;
      left: 0;
      width: 100%;
      height: 100%;
      background: radial-gradient(circle at 75% 30%, rgba(0,230,118,0.08) 0%, transparent 60%);
      pointer-events: none;
    }

    .particle {
      position: absolute;
      background: rgba(0,230,118,0.15);
      border-radius: 50%;
      filter: blur(1px);
      animation: float 8s infinite alternate;
    }

    @keyframes float {
      0% { transform: translateY(0px); }
      100% { transform: translateY(-30px); }
    }

    .stat-number {
      font-family: 'Inter', 'Roboto', sans-serif;
      font-size: 3rem;
      font-weight: 700;
      color: var(--primary);
    }

    .section-dark {
      background-color: var(--secondary-bg);
      padding: var(--section-padding);
    }

    .section-darker {
      background-color: #060b1c;
      padding: var(--section-padding);
    }

    .section-light-alt {
      background-color: rgba(26,35,64,0.5);
      padding: var(--section-padding);
    }

    .accordion-button {
      background-color: rgba(26,35,64,0.8);
      color: white;
      font-weight: 600;
      border: 1px solid rgba(255,255,255,0.08);
      border-radius: 12px !important;
      margin-bottom: 10px;
      transition: 0.2s;
    }

    .accordion-button:not(.collapsed) {
      background-color: rgba(0,230,118,0.1);
      color: var(--primary);
      border-color: var(--primary-dark);
      box-shadow: 0 0 12px rgba(0,230,118,0.3);
    }

    .accordion-button::after {
      filter: brightness(0) invert(1);
    }

    .accordion-body {
      background: rgba(255,255,255,0.02);
      color: var(--text-muted);
      border-radius: 0 0 12px 12px;
    }

    footer {
      background: #050a18;
      border-top: 1px solid rgba(255,255,255,0.05);
    }

    .social-icon {
      font-size: 1.5rem;
      margin-right: 15px;
      color: var(--text-muted);
      transition: color 0.2s;
    }

    .social-icon:hover {
      color: var(--primary);
    }

    @media (max-width: 768px) {
      h1 { font-size: 38px; }
      h2 { font-size: 28px; }
      .hero-section { min-height: 70vh; text-align: center; }
      .navbar-collapse { background: rgba(10,17,40,0.95); padding: 20px; border-radius: 16px; margin-top: 10px; }
      .search-box { width: 100%; }
    }

    @media (prefers-reduced-motion: reduce) {
      .pulse-btn, .particle, .glass-card {
        animation: none;
        transition: none;
      }
    }