/* roulang page: index */
:root {
      --primary: #6C38FF;
      --primary-hover: #5925e6;
      --secondary: #00F5A0;
      --secondary-dark: #00c782;
      --dark-canvas: #0D0F17;
      --card-bg: #171B26;
      --card-bg-elevated: #1E2333;
      --text-main: #F8FAFC;
      --text-muted: #94A3B8;
      --text-sub: #CBD5E1;
      --border-subtle: rgba(255, 255, 255, 0.08);
      --border-glow: rgba(108, 56, 255, 0.4);
      --glow-shadow: 0 12px 24px -10px rgba(108, 56, 255, 0.3);
      --radius-card: 12px;
      --radius-btn: 8px;
    }

    * {
      box-sizing: border-box;
    }

    body {
      background-color: var(--dark-canvas);
      color: var(--text-sub);
      font-family: system-ui, -apple-system, "PingFang SC", "Microsoft YaHei", sans-serif;
      letter-spacing: 0.02em;
      line-height: 1.75;
      margin: 0;
      padding: 0;
      overflow-x: hidden;
    }

    h1, h2, h3, h4, h5, h6 {
      color: var(--text-main);
      font-weight: 700;
      margin-bottom: 0.75rem;
    }

    p {
      margin-bottom: 1.25rem;
    }

    code, .tech-code {
      font-family: "JetBrains Mono", Consolas, monospace;
      color: var(--secondary);
    }

    a {
      text-decoration: none;
      transition: all 0.25s ease;
    }

    /* Top Bar */
    .top-bar {
      background: #080A0F;
      border-bottom: 1px solid var(--border-subtle);
      font-size: 0.8125rem;
      padding: 6px 0;
      color: var(--text-muted);
    }

    /* Main Navbar */
    .site-nav {
      background: rgba(13, 15, 23, 0.92);
      backdrop-filter: blur(12px);
      border-bottom: 1px solid var(--border-subtle);
      position: sticky;
      top: 0;
      z-index: 1030;
    }

    .brand-logo {
      font-size: 1.35rem;
      font-weight: 800;
      color: var(--text-main);
      display: flex;
      align-items: center;
      gap: 10px;
    }

    .brand-logo i {
      color: var(--primary);
    }

    .nav-link {
      color: var(--text-sub) !important;
      font-weight: 500;
      padding: 0.6rem 1rem !important;
      font-size: 0.95rem;
    }

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

    .btn-brand-primary {
      background-color: var(--primary);
      color: #fff;
      border: 1px solid transparent;
      border-radius: var(--radius-btn);
      padding: 0.6rem 1.4rem;
      font-weight: 600;
      transition: all 0.3s ease;
    }

    .btn-brand-primary:hover {
      background-color: var(--primary-hover);
      color: #fff;
      box-shadow: 0 0 15px rgba(108, 56, 255, 0.5);
      transform: translateY(-1px);
    }

    .btn-brand-secondary {
      background: rgba(0, 245, 160, 0.1);
      color: var(--secondary);
      border: 1px solid var(--secondary);
      border-radius: var(--radius-btn);
      padding: 0.6rem 1.4rem;
      font-weight: 600;
      transition: all 0.3s ease;
    }

    .btn-brand-secondary:hover {
      background: var(--secondary);
      color: #0D0F17;
      box-shadow: 0 0 15px rgba(0, 245, 160, 0.4);
      transform: translateY(-1px);
    }

    /* Sub-Nav Pill Strip */
    .pill-strip-wrapper {
      background: #11141E;
      border-top: 1px solid var(--border-subtle);
      border-bottom: 1px solid var(--border-subtle);
      padding: 10px 0;
      overflow-x: auto;
      white-space: nowrap;
      -webkit-overflow-scrolling: touch;
      scrollbar-width: none;
    }
    .pill-strip-wrapper::-webkit-scrollbar {
      display: none;
    }

    .nav-pill-item {
      display: inline-block;
      padding: 6px 18px;
      margin-right: 8px;
      border-radius: 20px;
      background: var(--card-bg);
      border: 1px solid var(--border-subtle);
      color: var(--text-sub);
      font-size: 0.875rem;
      font-weight: 500;
      cursor: pointer;
    }

    .nav-pill-item:hover, .nav-pill-item.active {
      background: rgba(108, 56, 255, 0.2);
      border-color: var(--primary);
      color: var(--text-main);
    }

    /* Sections Shared */
    section {
      padding: 85px 0;
      position: relative;
    }

    .section-alt {
      background-color: #121520;
    }

    .section-darker {
      background-color: #090B10;
    }

    .section-badge {
      display: inline-block;
      font-size: 0.8rem;
      text-transform: uppercase;
      letter-spacing: 0.08em;
      color: var(--secondary);
      background: rgba(0, 245, 160, 0.08);
      border: 1px solid rgba(0, 245, 160, 0.2);
      padding: 4px 12px;
      border-radius: 4px;
      margin-bottom: 1rem;
      font-weight: 600;
    }

    .section-heading-box {
      margin-bottom: 40px;
    }

    .section-heading-box h2 {
      font-size: 2.15rem;
      margin-bottom: 0.75rem;
    }

    .section-heading-desc {
      color: var(--text-muted);
      font-size: 1.05rem;
      max-width: 780px;
      margin: 0 auto;
    }

    /* Cards */
    .custom-card {
      background: var(--card-bg);
      border: 1px solid var(--border-subtle);
      border-radius: var(--radius-card);
      padding: 24px;
      transition: all 0.3s ease;
      height: 100%;
      position: relative;
      display: flex;
      flex-direction: column;
    }

    .custom-card:hover {
      transform: translateY(-4px);
      border-color: var(--border-glow);
      box-shadow: var(--glow-shadow);
    }

    /* Hero */
    .hero-section {
      background: radial-gradient(circle at 80% 20%, rgba(108, 56, 255, 0.2) 0%, transparent 50%),
                  radial-gradient(circle at 20% 80%, rgba(0, 245, 160, 0.08) 0%, transparent 40%),
                  #0D0F17;
      padding: 80px 0 60px 0;
    }

    .hero-h1 {
      font-size: 3rem;
      line-height: 1.25;
      font-weight: 800;
      margin-bottom: 1.25rem;
      background: linear-gradient(135deg, #FFFFFF 40%, #CBD5E1 100%);
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
    }

    .hero-lead {
      font-size: 1.125rem;
      line-height: 1.8;
      color: var(--text-sub);
      margin-bottom: 2rem;
    }

    .magazine-card {
      background: var(--card-bg);
      border: 1px solid var(--border-subtle);
      border-radius: var(--radius-card);
      overflow: hidden;
    }

    .magazine-card img {
      width: 100%;
      height: 230px;
      object-fit: cover;
    }

    /* Metrics Strip */
    .metric-value {
      font-size: 2.75rem;
      font-weight: 800;
      color: var(--secondary);
      line-height: 1;
      font-family: "JetBrains Mono", monospace;
    }

    /* Accordion FAQ */
    .accordion-item {
      background-color: var(--card-bg);
      border: 1px solid var(--border-subtle);
      border-radius: var(--radius-card) !important;
      margin-bottom: 12px;
      overflow: hidden;
    }

    .accordion-button {
      background-color: var(--card-bg);
      color: var(--text-main);
      font-weight: 600;
      font-size: 1.05rem;
      padding: 18px 22px;
      box-shadow: none !important;
    }

    .accordion-button:not(.collapsed) {
      background-color: var(--card-bg-elevated);
      color: var(--secondary);
      border-bottom: 1px solid var(--border-subtle);
    }

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

    .accordion-body {
      background-color: var(--card-bg);
      color: var(--text-sub);
      font-size: 0.95rem;
      line-height: 1.8;
      padding: 20px 22px;
    }

    /* Comparison Box */
    .comparison-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 20px;
    }

    .comp-box-traditional {
      background: rgba(239, 68, 68, 0.05);
      border: 1px solid rgba(239, 68, 68, 0.2);
      border-radius: var(--radius-card);
      padding: 24px;
    }

    .comp-box-ai {
      background: rgba(0, 245, 160, 0.05);
      border: 1px solid rgba(0, 245, 160, 0.25);
      border-radius: var(--radius-card);
      padding: 24px;
    }

    /* Form Controls */
    .form-control, .form-select {
      background-color: #11141F;
      border: 1px solid var(--border-subtle);
      color: var(--text-main);
      border-radius: 6px;
      padding: 12px 16px;
    }

    .form-control:focus, .form-select:focus {
      background-color: #141824;
      border-color: var(--primary);
      box-shadow: 0 0 0 0.25rem rgba(108, 56, 255, 0.25);
      color: #fff;
    }

    /* Footer */
    footer {
      background-color: #06070B;
      border-top: 1px solid var(--border-subtle);
      color: var(--text-muted);
      font-size: 0.9rem;
      padding: 60px 0 25px 0;
    }

    .footer-title {
      color: var(--text-main);
      font-size: 1.05rem;
      font-weight: 700;
      margin-bottom: 1.25rem;
    }

    .footer-links {
      list-style: none;
      padding: 0;
      margin: 0;
    }

    .footer-links li {
      margin-bottom: 0.6rem;
    }

    .footer-links a {
      color: var(--text-muted);
    }

    .footer-links a:hover {
      color: var(--secondary);
    }

    /* Responsive */
    @media (max-width: 991.98px) {
      .hero-h1 {
        font-size: 2.3rem;
      }
      .comparison-grid {
        grid-template-columns: 1fr;
      }
    }

    @media (max-width: 576px) {
      .hero-h1 {
        font-size: 1.85rem;
      }
      section {
        padding: 55px 0;
      }
    }