/* roulang page: index */
:root {
      --vx-primary: #1A56DB;
      --vx-primary-dark: #123e9b;
      --vx-primary-light: #4A7DF9;
      --vx-accent: #00D5A0;
      --vx-danger: #FF5A36;
      --vx-dark-bg: #0B132B;
      --vx-dark-card: #1C2541;
      --vx-light-bg: #F8FAFC;
      --vx-border: #E2E8F0;
      --vx-text-heading: #0F172A;
      --vx-text-body: #334155;
      --vx-text-muted: #64748B;
      --vx-radius-sm: 8px;
      --vx-radius-md: 12px;
      --vx-radius-lg: 16px;
      --vx-radius-pill: 9999px;
      --vx-shadow-subtle: 0 1px 3px rgba(0, 0, 0, 0.05), 0 10px 15px -5px rgba(0, 0, 0, 0.04);
      --vx-shadow-hover: 0 20px 25px -5px rgba(26, 86, 219, 0.12), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
    }

    *, *::before, *::after {
      box-sizing: border-box;
    }

    html {
      scroll-behavior: smooth;
    }

    body {
      font-family: system-ui, -apple-system, "Segoe UI", Roboto, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
      color: var(--vx-text-body);
      background-color: #FFFFFF;
      line-height: 1.75;
      overflow-x: hidden;
      margin: 0;
      padding: 0;
    }

    h1, h2, h3, h4, h5, h6 {
      color: var(--vx-text-heading);
      font-weight: 700;
      letter-spacing: -0.02em;
      line-height: 1.35;
    }

    a {
      text-decoration: none;
      color: var(--vx-primary);
      transition: all 0.25s ease;
    }
    a:hover {
      color: var(--vx-primary-dark);
    }

    .container-xl {
      max-width: 1280px;
    }

    /* Top utility bar */
    .site-topbar {
      background-color: #0A0F1D;
      color: #94A3B8;
      font-size: 0.825rem;
      border-bottom: 1px solid rgba(255, 255, 255, 0.08);
      padding: 6px 0;
    }
    .status-indicator {
      display: inline-block;
      width: 8px;
      height: 8px;
      border-radius: 50%;
      background-color: var(--vx-accent);
      box-shadow: 0 0 8px var(--vx-accent);
      margin-right: 6px;
      animation: pulse 2s infinite;
    }
    @keyframes pulse {
      0% { transform: scale(0.95); box-shadow: 0 0 0 0 rgba(0, 213, 160, 0.7); }
      70% { transform: scale(1.05); box-shadow: 0 0 0 6px rgba(0, 213, 160, 0); }
      100% { transform: scale(0.95); box-shadow: 0 0 0 0 rgba(0, 213, 160, 0); }
    }

    /* Main Navigation */
    .site-nav {
      background: rgba(255, 255, 255, 0.98);
      backdrop-filter: blur(12px);
      border-bottom: 1px solid var(--vx-border);
      position: sticky;
      top: 0;
      z-index: 1030;
      box-shadow: 0 4px 20px rgba(0, 0, 0, 0.03);
    }
    .brand-logo-text {
      font-size: 1.45rem;
      font-weight: 800;
      color: var(--vx-primary);
      display: flex;
      align-items: center;
      gap: 8px;
      letter-spacing: -0.03em;
    }
    .brand-logo-text i {
      font-size: 1.6rem;
      color: var(--vx-primary);
    }
    .nav-link {
      font-weight: 500;
      color: var(--vx-text-heading) !important;
      font-size: 0.95rem;
      padding: 0.5rem 0.9rem !important;
      position: relative;
    }
    .nav-link:hover, .nav-link.active {
      color: var(--vx-primary) !important;
    }
    .nav-badge-v4 {
      background: rgba(26, 86, 219, 0.1);
      color: var(--vx-primary);
      border: 1px solid rgba(26, 86, 219, 0.2);
      font-size: 0.72rem;
      font-weight: 600;
      padding: 4px 10px;
      border-radius: var(--vx-radius-pill);
    }

    /* Primary Buttons */
    .btn-vx-primary {
      background-color: var(--vx-primary);
      color: #FFFFFF !important;
      font-weight: 600;
      border-radius: var(--vx-radius-pill);
      padding: 0.65rem 1.6rem;
      border: 1px solid var(--vx-primary);
      display: inline-flex;
      align-items: center;
      gap: 6px;
      box-shadow: 0 4px 14px rgba(26, 86, 219, 0.35);
      min-height: 44px;
      min-width: 44px;
      transition: all 0.25s ease;
    }
    .btn-vx-primary:hover {
      background-color: var(--vx-primary-dark);
      border-color: var(--vx-primary-dark);
      transform: translateY(-2px);
      box-shadow: 0 6px 20px rgba(26, 86, 219, 0.45);
    }
    .btn-vx-outline {
      background: transparent;
      color: var(--vx-text-heading);
      border: 1px solid var(--vx-border);
      border-radius: var(--vx-radius-pill);
      padding: 0.65rem 1.6rem;
      font-weight: 600;
      min-height: 44px;
      min-width: 44px;
      display: inline-flex;
      align-items: center;
      gap: 6px;
    }
    .btn-vx-outline:hover {
      background: var(--vx-light-bg);
      border-color: var(--vx-text-muted);
      color: var(--vx-primary);
    }
    .btn-vx-accent {
      background-color: var(--vx-accent);
      color: #0A0F1D !important;
      font-weight: 700;
      border-radius: var(--vx-radius-pill);
      padding: 0.65rem 1.6rem;
      border: 1px solid var(--vx-accent);
      min-height: 44px;
      min-width: 44px;
      display: inline-flex;
      align-items: center;
      gap: 6px;
    }
    .btn-vx-accent:hover {
      background-color: #00bf8f;
      transform: translateY(-2px);
      box-shadow: 0 6px 18px rgba(0, 213, 160, 0.35);
    }

    /* Section Styles */
    .section-padding {
      padding: 5rem 0;
    }
    .section-title-wrap {
      max-width: 780px;
      margin: 0 auto 3.25rem;
      text-align: center;
    }
    .section-eyebrow {
      color: var(--vx-primary);
      text-transform: uppercase;
      font-weight: 700;
      font-size: 0.85rem;
      letter-spacing: 0.08em;
      margin-bottom: 0.5rem;
      display: inline-flex;
      align-items: center;
      gap: 6px;
    }
    .section-title {
      font-size: 2.15rem;
      margin-bottom: 1rem;
    }
    .section-lead {
      color: var(--vx-text-muted);
      font-size: 1.05rem;
      line-height: 1.8;
      margin: 0;
    }

    /* Hero Section */
    .hero-banner-section {
      background: linear-gradient(135deg, #091124 0%, #0F1E40 60%, #152A5A 100%);
      color: #FFFFFF;
      position: relative;
      overflow: hidden;
      padding: 4.5rem 0 5.5rem;
    }
    .hero-banner-section::before {
      content: "";
      position: absolute;
      inset: 0;
      background: radial-gradient(circle at 80% 20%, rgba(26, 86, 219, 0.3) 0%, transparent 60%);
      pointer-events: none;
    }
    .hero-badge-live {
      display: inline-flex;
      align-items: center;
      gap: 8px;
      background: rgba(255, 90, 54, 0.15);
      border: 1px solid rgba(255, 90, 54, 0.35);
      color: #FFA18F;
      font-size: 0.8rem;
      font-weight: 700;
      padding: 6px 14px;
      border-radius: var(--vx-radius-pill);
      margin-bottom: 1.5rem;
    }
    .live-dot {
      width: 8px;
      height: 8px;
      background: var(--vx-danger);
      border-radius: 50%;
      box-shadow: 0 0 8px var(--vx-danger);
    }
    .hero-title {
      font-size: 2.85rem;
      color: #FFFFFF;
      line-height: 1.25;
      margin-bottom: 1.25rem;
    }
    .hero-desc {
      color: #CBD5E1;
      font-size: 1.1rem;
      line-height: 1.8;
      margin-bottom: 2rem;
      max-width: 600px;
    }
    .hero-quiz-card {
      background: #FFFFFF;
      color: var(--vx-text-body);
      border-radius: var(--vx-radius-lg);
      padding: 2rem;
      box-shadow: 0 25px 50px -12px rgba(0, 0, 0, 0.4);
      position: relative;
      border: 1px solid rgba(255, 255, 255, 0.2);
    }
    .quiz-opt-btn {
      width: 100%;
      text-align: left;
      border: 1px solid var(--vx-border);
      border-radius: var(--vx-radius-sm);
      padding: 0.85rem 1rem;
      background: #FFFFFF;
      font-size: 0.925rem;
      font-weight: 500;
      color: var(--vx-text-heading);
      margin-bottom: 0.75rem;
      display: flex;
      align-items: center;
      justify-content: space-between;
      transition: all 0.2s ease;
      min-height: 44px;
    }
    .quiz-opt-btn:hover, .quiz-opt-btn.active {
      border-color: var(--vx-primary);
      background: rgba(26, 86, 219, 0.04);
      color: var(--vx-primary);
    }
    .quiz-result-box {
      background: #F1F5F9;
      border-radius: var(--vx-radius-sm);
      padding: 1rem;
      font-size: 0.875rem;
      border-left: 4px solid var(--vx-primary);
      margin-top: 1rem;
    }

    /* Countdown Strip */
    .countdown-strip {
      background: #0D1630;
      border-bottom: 1px solid rgba(255, 255, 255, 0.08);
      padding: 1.25rem 0;
      color: #FFFFFF;
    }
    .count-unit {
      background: rgba(255, 255, 255, 0.06);
      border: 1px solid rgba(255, 255, 255, 0.12);
      border-radius: var(--vx-radius-sm);
      padding: 0.4rem 0.8rem;
      font-weight: 800;
      font-size: 1.25rem;
      color: var(--vx-accent);
      min-width: 48px;
      text-align: center;
      display: inline-block;
    }

    /* Feature Cards */
    .feature-card {
      background: #FFFFFF;
      border: 1px solid var(--vx-border);
      border-radius: var(--vx-radius-md);
      padding: 2.25rem 1.75rem;
      box-shadow: var(--vx-shadow-subtle);
      transition: all 0.3s cubic-bezier(0.165, 0.84, 0.44, 1);
      height: 100%;
    }
    .feature-card:hover {
      transform: translateY(-6px);
      border-color: var(--vx-primary);
      box-shadow: var(--vx-shadow-hover);
    }
    .feature-icon-box {
      width: 54px;
      height: 54px;
      border-radius: var(--vx-radius-md);
      background: rgba(26, 86, 219, 0.08);
      color: var(--vx-primary);
      display: flex;
      align-items: center;
      justify-content: center;
      font-size: 1.5rem;
      margin-bottom: 1.25rem;
      transition: all 0.3s ease;
    }
    .feature-card:hover .feature-icon-box {
      background: var(--vx-primary);
      color: #FFFFFF;
    }

    /* Plan & Matrix Cards */
    .plan-card {
      border: 1px solid var(--vx-border);
      border-radius: var(--vx-radius-lg);
      background: #FFFFFF;
      padding: 2.5rem 2rem;
      position: relative;
      height: 100%;
      box-shadow: var(--vx-shadow-subtle);
      transition: all 0.3s ease;
    }
    .plan-card.featured {
      border: 2px solid var(--vx-primary);
      box-shadow: 0 15px 35px -5px rgba(26, 86, 219, 0.2);
      transform: scale(1.02);
    }
    .plan-badge-float {
      position: absolute;
      top: -14px;
      left: 50%;
      transform: translateX(-50%);
      background: var(--vx-primary);
      color: #FFFFFF;
      font-size: 0.75rem;
      font-weight: 700;
      padding: 4px 16px;
      border-radius: var(--vx-radius-pill);
      letter-spacing: 0.05em;
    }
    .plan-price-num {
      font-size: 2.25rem;
      font-weight: 800;
      color: var(--vx-text-heading);
    }
    .plan-feature-list {
      list-style: none;
      padding: 0;
      margin: 1.75rem 0 2rem;
    }
    .plan-feature-list li {
      font-size: 0.925rem;
      margin-bottom: 0.75rem;
      display: flex;
      align-items: center;
      gap: 10px;
    }
    .plan-feature-list li i {
      color: var(--vx-accent);
      font-size: 1.1rem;
    }

    /* Immersive Section */
    .immersive-dark-section {
      background: radial-gradient(circle at 50% 30%, #152244 0%, #080D1A 80%);
      color: #FFFFFF;
      padding: 6rem 0;
      position: relative;
    }
    .terminal-window {
      background: #050811;
      border: 1px solid rgba(255, 255, 255, 0.12);
      border-radius: var(--vx-radius-md);
      overflow: hidden;
      box-shadow: 0 25px 60px rgba(0, 0, 0, 0.6);
    }
    .terminal-bar {
      background: #0E1626;
      padding: 10px 16px;
      border-bottom: 1px solid rgba(255, 255, 255, 0.08);
      display: flex;
      align-items: center;
      gap: 8px;
    }
    .term-dot {
      width: 10px;
      height: 10px;
      border-radius: 50%;
      display: inline-block;
    }
    .terminal-body {
      padding: 1.5rem;
      font-family: SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", "Courier New", monospace;
      font-size: 0.85rem;
      color: #A5B4FC;
      line-height: 1.6;
    }

    /* Scenario Tabs */
    .scenario-nav-pills .nav-link {
      background: #FFFFFF;
      border: 1px solid var(--vx-border);
      border-radius: var(--vx-radius-md);
      padding: 1rem 1.25rem !important;
      font-weight: 600;
      margin-bottom: 0.75rem;
      display: flex;
      align-items: center;
      justify-content: space-between;
      color: var(--vx-text-heading) !important;
      transition: all 0.2s ease;
    }
    .scenario-nav-pills .nav-link.active {
      background: var(--vx-primary);
      border-color: var(--vx-primary);
      color: #FFFFFF !important;
      box-shadow: 0 8px 20px rgba(26, 86, 219, 0.25);
    }

    /* Metrics Strip */
    .stats-bar-section {
      background: #FFFFFF;
      border-top: 1px solid var(--vx-border);
      border-bottom: 1px solid var(--vx-border);
      padding: 3.5rem 0;
    }
    .stat-number {
      font-size: 2.75rem;
      font-weight: 800;
      color: var(--vx-primary);
      line-height: 1.1;
      letter-spacing: -0.03em;
    }

    /* Comparison Table */
    .comparison-table {
      width: 100%;
      border-collapse: separate;
      border-spacing: 0;
      border: 1px solid var(--vx-border);
      border-radius: var(--vx-radius-md);
      overflow: hidden;
      background: #FFFFFF;
    }
    .comparison-table th, .comparison-table td {
      padding: 1.15rem 1.25rem;
      border-bottom: 1px solid var(--vx-border);
      vertical-align: middle;
      font-size: 0.95rem;
    }
    .comparison-table th {
      background: #F8FAFC;
      font-weight: 700;
      color: var(--vx-text-heading);
    }
    .comparison-table tr:last-child td {
      border-bottom: none;
    }
    .table-col-highlight {
      background: rgba(26, 86, 219, 0.03);
      border-left: 2px solid var(--vx-primary);
      border-right: 2px solid var(--vx-primary);
      font-weight: 600;
      color: var(--vx-text-heading);
    }

    /* Accordion FAQ */
    .accordion-item {
      border: 1px solid var(--vx-border);
      border-radius: var(--vx-radius-md) !important;
      margin-bottom: 1rem;
      overflow: hidden;
      background: #FFFFFF;
    }
    .accordion-button {
      font-weight: 700;
      font-size: 1.05rem;
      color: var(--vx-text-heading);
      padding: 1.35rem 1.5rem;
      background-color: #FFFFFF;
      box-shadow: none !important;
    }
    .accordion-button:not(.collapsed) {
      color: var(--vx-primary);
      background-color: rgba(26, 86, 219, 0.02);
    }
    .accordion-body {
      padding: 0 1.5rem 1.5rem;
      color: var(--vx-text-body);
      line-height: 1.8;
      font-size: 0.95rem;
    }

    /* Testimonial Card */
    .testimonial-card {
      background: #FFFFFF;
      border: 1px solid var(--vx-border);
      border-radius: var(--vx-radius-md);
      padding: 2rem;
      height: 100%;
      display: flex;
      flex-direction: column;
      justify-content: space-between;
      box-shadow: var(--vx-shadow-subtle);
    }

    /* Footer */
    .site-footer {
      background: #0B132B;
      color: #94A3B8;
      padding: 5rem 0 2rem;
      font-size: 0.9rem;
      border-top: 1px solid rgba(255, 255, 255, 0.08);
    }
    .site-footer h6 {
      color: #FFFFFF;
      font-size: 1rem;
      margin-bottom: 1.25rem;
    }
    .site-footer ul {
      list-style: none;
      padding: 0;
      margin: 0;
    }
    .site-footer ul li {
      margin-bottom: 0.65rem;
    }
    .site-footer ul li a {
      color: #94A3B8;
    }
    .site-footer ul li a:hover {
      color: #FFFFFF;
    }
    .footer-divider {
      border-color: rgba(255, 255, 255, 0.08);
      margin: 3.5rem 0 2rem;
    }

    /* Fixed Bottom Bar */
    .fixed-action-bar {
      position: fixed;
      bottom: 0;
      left: 0;
      right: 0;
      background: rgba(11, 19, 43, 0.95);
      backdrop-filter: blur(8px);
      border-top: 1px solid rgba(255, 255, 255, 0.15);
      z-index: 1020;
      padding: 10px 0;
      color: #FFFFFF;
    }

    /* Image responsive style */
    .img-fluid-rounded {
      width: 100%;
      height: auto;
      border-radius: var(--vx-radius-md);
      object-fit: cover;
    }

    @media (max-width: 991.98px) {
      .hero-title {
        font-size: 2.2rem;
      }
      .plan-card.featured {
        transform: none;
      }
      .section-padding {
        padding: 3.5rem 0;
      }
    }