/* roulang page: index */
:root {
      --racing-cyan: #0FE0D6;
      --deep-rock: #121212;
      --electric-purple: #8B5CF6;
      --warm-orange: #F97316;
      --card-bg: #1A1A1A;
      --card-border: rgba(255,255,255,0.05);
      --text-body: #E5E7EB;
      --text-muted: #9CA3AF;
      --text-title: #FFFFFF;
    }
    * {
      box-sizing: border-box;
    }
    body {
      margin: 0;
      font-family: 'PingFang SC', 'Microsoft YaHei', 'Hiragino Sans GB', sans-serif;
      background-color: #0F0F0F;
      color: #E5E7EB;
      line-height: 1.7;
      -webkit-font-smoothing: antialiased;
    }
    a, button, input, textarea {
      font-family: inherit;
    }
    img {
      max-width: 100%;
      height: auto;
      display: block;
    }
    .container {
      max-width: 1280px;
      margin-left: auto;
      margin-right: auto;
      padding-left: 1.5rem;
      padding-right: 1.5rem;
    }
    @media (min-width: 1024px) {
      .container {
        padding-left: 2rem;
        padding-right: 2rem;
      }
    }
    .section-padding {
      padding-top: 100px;
      padding-bottom: 100px;
    }
    @media (max-width: 768px) {
      .section-padding {
        padding-top: 60px;
        padding-bottom: 60px;
      }
    }
    .card-hover {
      transition: border-color 0.2s ease, box-shadow 0.2s ease;
      border: 1px solid var(--card-border);
      background-color: rgba(26,26,26,0.9);
    }
    .card-hover:hover {
      border-color: var(--racing-cyan);
      box-shadow: 0 0 20px rgba(14,224,214,0.15);
    }
    .btn-primary {
      background-color: var(--racing-cyan);
      color: #121212;
      font-weight: 600;
      border-radius: 8px;
      transition: all 0.2s;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      text-decoration: none;
      border: none;
      cursor: pointer;
    }
    .btn-primary:hover {
      filter: brightness(1.15);
      box-shadow: 0 0 18px rgba(14,224,214,0.5);
    }
    .btn-secondary {
      background: transparent;
      border: 1.5px solid var(--racing-cyan);
      color: var(--racing-cyan);
      font-weight: 600;
      border-radius: 8px;
      transition: all 0.2s;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      text-decoration: none;
      cursor: pointer;
    }
    .btn-secondary:hover {
      background-color: rgba(14,224,214,0.1);
    }
    .btn-purple {
      background-color: var(--electric-purple);
      color: white;
      font-weight: 600;
      border-radius: 8px;
      transition: all 0.2s;
      border: none;
      cursor: pointer;
    }
    .btn-purple:hover {
      background: linear-gradient(135deg, #7c3aed, #0FE0D6);
      box-shadow: 0 0 18px rgba(139,92,246,0.4);
    }
    input, textarea {
      background-color: #1F1F1F;
      border: 1px solid #374151;
      color: white;
      border-radius: 8px;
      padding: 12px 16px;
      transition: border 0.2s;
      width: 100%;
    }
    input:focus, textarea:focus {
      outline: none;
      border-color: var(--racing-cyan);
    }
    .nav-link {
      color: #9CA3AF;
      font-size: 0.875rem;
      transition: color 0.2s;
      text-decoration: none;
    }
    .nav-link:hover {
      color: var(--racing-cyan);
    }
    .h1-title {
      font-size: clamp(2rem, 5vw, 3rem);
      font-weight: 700;
      letter-spacing: -0.5px;
      line-height: 1.2;
      color: white;
    }
    .h2-title {
      font-size: 1.75rem;
      font-weight: 600;
      color: white;
      margin-bottom: 1rem;
    }
    .h3-title {
      font-size: 1.25rem;
      font-weight: 600;
      color: white;
    }
    .data-number {
      font-family: 'DIN Alternate', 'Inter', sans-serif;
      font-weight: 700;
    }
    .glow-text {
      color: var(--racing-cyan);
    }
    .purple-text {
      color: var(--electric-purple);
    }
    .muted-text {
      color: #9CA3AF;
    }
    .accordion-content {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease;
      background-color: rgba(26,26,26,0.6);
      border-radius: 0 0 12px 12px;
    }
    .accordion-item.active .accordion-content {
      max-height: 200px;
    }
    .accordion-item.active .accordion-header {
      border-color: var(--racing-cyan);
    }
    .hero-bg {
      background-image: url('/assets/images/backpic/back-1.webp');
      background-size: cover;
      background-position: center;
      position: relative;
    }
    .hero-overlay {
      background: rgba(0,0,0,0.75);
      position: absolute;
      inset: 0;
    }
    @media (max-width: 768px) {
      .mobile-nav {
        display: flex;
        position: fixed;
        bottom: 0;
        left: 0;
        right: 0;
        background: #121212;
        border-top: 1px solid #2d2d2d;
        z-index: 50;
        justify-content: space-around;
        padding: 0.75rem 0.5rem;
      }
      .desktop-nav {
        display: none;
      }
      .hero-split {
        flex-direction: column;
      }
      .hero-visual {
        height: 280px;
        order: -1;
      }
    }
    @media (min-width: 769px) {
      .mobile-nav {
        display: none;
      }
      .desktop-nav {
        display: flex;
      }
      .hero-split {
        flex-direction: row;
      }
    }
    .service-card-bar {
      width: 4px;
      background: linear-gradient(to bottom, var(--racing-cyan), var(--electric-purple));
      border-radius: 4px;
      margin-right: 1.25rem;
      transition: width 0.2s;
    }
    .card-hover:hover .service-card-bar {
      width: 8px;
    }
    footer a {
      color: #9CA3AF;
      text-decoration: none;
      transition: color 0.2s;
    }
    footer a:hover {
      color: var(--racing-cyan);
    }