/* roulang page: index */
:root {
      --obsidian: #0B0C10;
      --carbon: #1A1C23;
      --volt: #A259FF;
      --cyan: #00F5D4;
      --warm: #F4F4F9;
      --cool: #9A9CAE;
      --border: #2A2C35;
    }
    * {
      box-sizing: border-box;
    }
    body {
      font-family: 'Inter', 'Noto Sans SC', system-ui, sans-serif;
      margin: 0;
      background-color: var(--obsidian);
      color: var(--warm);
      line-height: 1.6;
      -webkit-font-smoothing: antialiased;
    }
    .nav-link {
      transition: color 0.2s ease, border-left 0.2s ease;
      border-left: 3px solid transparent;
      padding-left: 1rem;
      display: block;
    }
    .nav-link:hover, .nav-link.active {
      color: var(--volt);
    }
    .nav-link.active {
      border-left-color: var(--cyan);
    }
    .btn-primary {
      background-color: var(--volt);
      color: white;
      border-radius: 8px;
      padding: 0.75rem 1.5rem;
      font-weight: 600;
      transition: all 0.25s ease;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      gap: 0.5rem;
      border: none;
      cursor: pointer;
      white-space: nowrap;
    }
    .btn-primary:hover {
      background-color: #8A3FE0;
      box-shadow: 0 0 20px rgba(162,89,255,0.45);
      transform: translateY(-1px);
    }
    .btn-outline {
      background: transparent;
      border: 1px solid var(--volt);
      color: var(--volt);
      border-radius: 8px;
      padding: 0.75rem 1.5rem;
      font-weight: 600;
      transition: all 0.25s ease;
      display: inline-flex;
      align-items: center;
      gap: 0.5rem;
      cursor: pointer;
    }
    .btn-outline:hover {
      background-color: var(--volt);
      color: white;
    }
    .card-hover {
      transition: all 0.3s ease;
      border: 1px solid var(--border);
      background-color: var(--carbon);
      border-radius: 16px;
    }
    .card-hover:hover {
      border-color: var(--volt);
      transform: translateY(-6px);
      box-shadow: 0 12px 24px rgba(162,89,255,0.15);
    }
    .faq-item {
      border-bottom: 1px solid var(--border);
    }
    .faq-question {
      background-color: var(--carbon);
      padding: 1.25rem 1.5rem;
      cursor: pointer;
      display: flex;
      justify-content: space-between;
      align-items: center;
      font-weight: 600;
      transition: background 0.2s;
    }
    .faq-question:hover {
      background-color: #22252F;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.35s ease;
      background-color: var(--obsidian);
      border-left: 3px solid var(--volt);
      padding: 0 1.5rem;
    }
    .faq-item.open .faq-answer {
      max-height: 300px;
      padding: 1.25rem 1.5rem;
    }
    .faq-item.open .faq-icon {
      transform: rotate(45deg);
    }
    .faq-icon {
      transition: transform 0.25s ease;
    }
    input:focus, textarea:focus {
      outline: none;
      border-color: var(--volt);
      box-shadow: 0 0 0 3px rgba(162,89,255,0.25);
    }
    .section-gap {
      margin-top: 7.5rem;
      margin-bottom: 7.5rem;
    }
    @media (max-width: 1023px) {
      .section-gap {
        margin-top: 5rem;
        margin-bottom: 5rem;
      }
    }
    @media (max-width: 767px) {
      .nav-drawer {
        display: none;
      }
      .nav-drawer.open {
        display: flex;
        flex-direction: column;
        position: absolute;
        top: 64px;
        left: 0;
        width: 100%;
        background: var(--obsidian);
        padding: 1.5rem;
        z-index: 50;
        border-bottom: 1px solid var(--border);
      }
      .mobile-nav-toggle {
        display: block;
      }
      .hamburger-line {
        display: block;
        width: 24px;
        height: 2px;
        background: var(--warm);
        margin: 5px 0;
        transition: 0.2s;
      }
    }
    @media (min-width: 768px) {
      .mobile-nav-toggle {
        display: none;
      }
      .nav-drawer {
        display: flex !important;
        flex-direction: column;
        height: 100%;
      }
    }
    .gradient-text {
      background: linear-gradient(135deg, #A259FF 0%, #00F5D4 100%);
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
      background-clip: text;
    }