/* roulang page: index */
:root {
      --primary: #0F4C81;
      --primary-dark: #0A3258;
      --secondary: #00A3E0;
      --accent: #F58220;
      --accent-hover: #DE6D0E;
      --bg-main: #F8FAFC;
      --bg-white: #FFFFFF;
      --bg-dark: #0B192C;
      --text-title: #1E293B;
      --text-body: #475569;
      --text-muted: #94A3B8;
      --border-color: #E2E8F0;
      --radius-sm: 6px;
      --radius-md: 8px;
      --shadow-sm: 0 4px 20px rgba(15, 76, 129, 0.05);
      --shadow-hover: 0 12px 28px rgba(15, 76, 129, 0.12);
      --transition: all 0.25s ease-in-out;
    }

    /* Reset & Base */
    *, *::before, *::after {
      box-sizing: border-box;
    }
    body {
      margin: 0;
      padding: 0;
      font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
      color: var(--text-body);
      background-color: var(--bg-main);
      line-height: 1.6;
      -webkit-font-smoothing: antialiased;
    }
    h1, h2, h3, h4, h5, h6 {
      color: var(--text-title);
      font-weight: 700;
      line-height: 1.35;
      margin-top: 0;
    }
    a {
      color: var(--primary);
      text-decoration: none;
      transition: var(--transition);
    }
    a:hover, a:focus {
      color: var(--secondary);
    }
    img {
      max-width: 100%;
      height: auto;
      display: block;
      border-radius: var(--radius-md);
    }

    /* Container Custom */
    .site-container {
      max-width: 1200px;
      margin-left: auto;
      margin-right: auto;
      padding-left: 20px;
      padding-right: 20px;
    }

    /* Buttons */
    .btn {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      min-height: 46px;
      min-width: 130px;
      padding: 10px 24px;
      font-size: 15px;
      font-weight: 600;
      border-radius: var(--radius-sm);
      cursor: pointer;
      border: 1px solid transparent;
      transition: var(--transition);
      text-align: center;
    }
    .btn-accent {
      background-color: var(--accent);
      color: #FFFFFF;
      box-shadow: 0 4px 14px rgba(245, 130, 32, 0.3);
    }
    .btn-accent:hover {
      background-color: var(--accent-hover);
      color: #FFFFFF;
      transform: translateY(-2px);
    }
    .btn-primary {
      background-color: var(--primary);
      color: #FFFFFF;
    }
    .btn-primary:hover {
      background-color: var(--primary-dark);
      color: #FFFFFF;
      transform: translateY(-2px);
    }
    .btn-outline {
      background-color: transparent;
      border-color: var(--primary);
      color: var(--primary);
    }
    .btn-outline:hover {
      background-color: var(--primary);
      color: #FFFFFF;
    }

    /* Header & Navigation */
    .site-header {
      position: sticky;
      top: 0;
      z-index: 999;
      background: #FFFFFF;
      box-shadow: 0 2px 10px rgba(0,0,0,0.06);
    }
    .header-top {
      border-bottom: 1px solid var(--border-color);
      padding: 12px 0;
    }
    .brand-wrap {
      display: flex;
      align-items: center;
      gap: 12px;
    }
    .brand-icon {
      width: 36px;
      height: 36px;
      background: var(--primary);
      border-radius: 8px;
      display: flex;
      align-items: center;
      justify-content: center;
      color: #FFFFFF;
      font-weight: 900;
      font-size: 18px;
    }
    .brand-title {
      font-size: 20px;
      font-weight: 800;
      color: var(--text-title);
      margin: 0;
      letter-spacing: -0.5px;
    }
    .header-top-right {
      display: flex;
      align-items: center;
      justify-content: flex-end;
      gap: 20px;
    }
    .hotline {
      font-size: 14px;
      color: var(--text-body);
      font-weight: 500;
    }
    .hotline span {
      color: var(--primary);
      font-weight: 700;
    }
    .header-nav {
      background: #F1F5F9;
      padding: 0;
    }
    .nav-list {
      display: flex;
      align-items: center;
      list-style: none;
      margin: 0;
      padding: 0;
      overflow-x: auto;
      white-space: nowrap;
    }
    .nav-list li a {
      display: block;
      padding: 14px 20px;
      font-size: 14px;
      font-weight: 600;
      color: var(--text-body);
      position: relative;
    }
    .nav-list li a:hover,
    .nav-list li a.active {
      color: var(--primary);
      background-color: #E2E8F0;
    }
    .nav-list li a.active::after {
      content: '';
      position: absolute;
      bottom: 0;
      left: 0;
      right: 0;
      height: 3px;
      background: var(--primary);
    }

    /* Section Global */
    section {
      padding: 96px 0;
      position: relative;
    }
    .bg-light {
      background-color: var(--bg-main);
    }
    .bg-white {
      background-color: var(--bg-white);
    }
    .section-header {
      margin-bottom: 56px;
      text-align: center;
    }
    .section-tag {
      display: inline-block;
      padding: 4px 12px;
      background: rgba(0, 163, 224, 0.1);
      color: var(--secondary);
      border-radius: 4px;
      font-size: 13px;
      font-weight: 700;
      text-transform: uppercase;
      margin-bottom: 12px;
      letter-spacing: 0.5px;
    }
    .section-title {
      font-size: 32px;
      margin-bottom: 16px;
    }
    .section-desc {
      max-width: 760px;
      margin: 0 auto;
      font-size: 15px;
      color: var(--text-body);
    }

    /* Card Standard */
    .app-card {
      background: #FFFFFF;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-md);
      padding: 32px 24px;
      box-shadow: var(--shadow-sm);
      transition: var(--transition);
      height: 100%;
      display: flex;
      flex-direction: column;
    }
    .app-card:hover {
      box-shadow: var(--shadow-hover);
      transform: translateY(-4px);
      border-color: #CBD5E1;
    }

    /* 1. Hero Carousel & Selection Survey */
    #hero {
      padding: 70px 0 90px;
      background: linear-gradient(135deg, #F8FAFC 0%, #EDF2F7 100%);
      border-bottom: 1px solid var(--border-color);
    }
    .hero-h1 {
      font-size: 40px;
      line-height: 1.25;
      margin-bottom: 20px;
      color: var(--text-title);
    }
    .hero-lead {
      font-size: 16px;
      line-height: 1.8;
      color: var(--text-body);
      margin-bottom: 30px;
    }
    .hero-cta-group {
      display: flex;
      gap: 16px;
      margin-bottom: 40px;
      flex-wrap: wrap;
    }
    .survey-box {
      background: #FFFFFF;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-md);
      padding: 28px;
      box-shadow: var(--shadow-sm);
    }
    .survey-title {
      font-size: 18px;
      margin-bottom: 16px;
      display: flex;
      align-items: center;
      gap: 8px;
      color: var(--primary);
    }
    .survey-option-group {
      display: flex;
      flex-wrap: wrap;
      gap: 10px;
      margin-bottom: 20px;
    }
    .survey-btn-opt {
      padding: 8px 16px;
      font-size: 13px;
      background: #F1F5F9;
      border: 1px solid #CBD5E1;
      border-radius: var(--radius-sm);
      cursor: pointer;
      color: var(--text-body);
      transition: var(--transition);
    }
    .survey-btn-opt.active, .survey-btn-opt:hover {
      background: var(--primary);
      color: #FFFFFF;
      border-color: var(--primary);
    }
    .survey-result-preview {
      background: #F8FAFC;
      border: 1px dashed #94A3B8;
      padding: 16px;
      border-radius: var(--radius-sm);
      font-size: 13px;
      color: var(--text-body);
      margin-bottom: 20px;
    }

    /* 2. Architecture Overview */
    .spec-item {
      display: flex;
      align-items: flex-start;
      gap: 12px;
      margin-bottom: 16px;
    }
    .spec-badge {
      padding: 4px 8px;
      background: #E2E8F0;
      color: var(--primary);
      border-radius: 4px;
      font-size: 12px;
      font-weight: 700;
      white-space: nowrap;
    }

    /* 3. Triple Points */
    .point-icon {
      font-size: 24px;
      color: var(--secondary);
      margin-bottom: 16px;
    }

    /* 4. Core Strengths 6-Grid */
    .grid-cell {
      margin-bottom: 24px;
    }

    /* 5. Solutions */
    .solution-card-header {
      border-bottom: 1px solid var(--border-color);
      padding-bottom: 16px;
      margin-bottom: 20px;
    }
    .solution-features {
      list-style: none;
      margin: 0 0 24px 0;
      padding: 0;
      font-size: 14px;
    }
    .solution-features li {
      padding: 6px 0;
      position: relative;
      padding-left: 20px;
    }
    .solution-features li::before {
      content: '✔';
      position: absolute;
      left: 0;
      color: var(--secondary);
    }

    /* 6. Dark Section */
    .dark-section {
      background-color: var(--bg-dark);
      color: #E2E8F0;
    }
    .dark-section h2, .dark-section h3, .dark-section h4 {
      color: #FFFFFF;
    }
    .dark-section p {
      color: #94A3B8;
    }
    .dark-card {
      background: rgba(255, 255, 255, 0.05);
      border: 1px solid rgba(255, 255, 255, 0.1);
      border-radius: var(--radius-md);
      padding: 24px;
      margin-bottom: 20px;
    }

    /* 7. Live Scenarios Tabs */
    .tab-header {
      display: flex;
      gap: 12px;
      margin-bottom: 30px;
      border-bottom: 2px solid var(--border-color);
      padding-bottom: 8px;
      overflow-x: auto;
    }
    .tab-nav-btn {
      background: none;
      border: none;
      padding: 10px 20px;
      font-size: 16px;
      font-weight: 700;
      color: var(--text-muted);
      cursor: pointer;
      transition: var(--transition);
      border-radius: var(--radius-sm);
    }
    .tab-nav-btn.active {
      color: var(--primary);
      background: #E2E8F0;
    }
    .tab-content-panel {
      display: none;
    }
    .tab-content-panel.active {
      display: block;
    }

    /* 8. Metrics Bar */
    .metric-box {
      text-align: center;
      padding: 24px 16px;
      background: #FFFFFF;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-md);
    }
    .metric-num {
      font-size: 38px;
      font-weight: 800;
      color: var(--primary);
      line-height: 1.1;
      margin-bottom: 8px;
    }
    .metric-unit {
      font-size: 18px;
      color: var(--accent);
      margin-left: 2px;
    }

    /* 9. Success Story */
    .story-wrapper {
      background: #FFFFFF;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-md);
      overflow: hidden;
      padding: 40px;
      box-shadow: var(--shadow-sm);
    }
    .timeline-steps {
      display: flex;
      justify-content: space-between;
      margin-top: 30px;
      position: relative;
    }
    .timeline-step {
      text-align: center;
      flex: 1;
      position: relative;
    }
    .timeline-step::before {
      content: '';
      position: absolute;
      top: 12px;
      left: 0;
      right: 0;
      height: 2px;
      background: var(--border-color);
      z-index: 1;
    }
    .step-dot {
      width: 24px;
      height: 24px;
      background: var(--primary);
      color: #FFF;
      border-radius: 50%;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      font-size: 12px;
      font-weight: 700;
      position: relative;
      z-index: 2;
      margin-bottom: 8px;
    }

    /* 10. Social Proof Testimonials */
    .testimonial-card {
      background: #FFFFFF;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-md);
      padding: 28px;
      height: 100%;
      display: flex;
      flex-direction: column;
      justify-content: space-between;
    }
    .star-rating {
      color: var(--accent);
      font-size: 14px;
      margin-bottom: 12px;
    }
    .client-author {
      margin-top: 20px;
      display: flex;
      align-items: center;
      gap: 12px;
    }
    .client-avatar {
      width: 44px;
      height: 44px;
      border-radius: 50%;
      background: #E2E8F0;
      display: flex;
      align-items: center;
      justify-content: center;
      font-weight: 700;
      color: var(--primary);
    }

    /* 11. Insights & News */
    .news-card {
      background: #FFFFFF;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-md);
      overflow: hidden;
      height: 100%;
      display: flex;
      flex-direction: column;
    }
    .news-body {
      padding: 24px;
      flex-grow: 1;
      display: flex;
      flex-direction: column;
      justify-content: space-between;
    }
    .news-date {
      font-size: 12px;
      color: var(--text-muted);
      margin-bottom: 8px;
    }

    /* 12. Objections Accordion */
    .faq-list {
      max-width: 900px;
      margin: 0 auto;
    }
    .faq-item {
      background: #FFFFFF;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-md);
      margin-bottom: 16px;
      overflow: hidden;
    }
    .faq-question {
      padding: 20px 24px;
      font-weight: 700;
      font-size: 16px;
      color: var(--text-title);
      cursor: pointer;
      display: flex;
      justify-content: space-between;
      align-items: center;
    }
    .faq-question::after {
      content: '+';
      font-size: 20px;
      color: var(--secondary);
    }
    .faq-item.active .faq-question::after {
      content: '−';
    }
    .faq-answer {
      display: none;
      padding: 0 24px 20px;
      font-size: 14px;
      color: var(--text-body);
      line-height: 1.7;
    }
    .faq-item.active .faq-answer {
      display: block;
    }

    /* 13. Final Action & Form */
    .final-section {
      background: linear-gradient(135deg, #0F4C81 0%, #0A3258 100%);
      color: #FFFFFF;
    }
    .final-section h2, .final-section h3 {
      color: #FFFFFF;
    }
    .final-section p {
      color: #CBD5E1;
    }
    .form-wrapper {
      background: #FFFFFF;
      padding: 32px;
      border-radius: var(--radius-md);
      color: var(--text-title);
    }
    .form-group {
      margin-bottom: 16px;
    }
    .form-label {
      font-size: 13px;
      font-weight: 600;
      margin-bottom: 6px;
      display: block;
      color: var(--text-title);
    }
    .form-input {
      width: 100%;
      height: 44px;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-sm);
      padding: 0 12px;
      font-size: 14px;
      transition: var(--transition);
    }
    .form-input:focus {
      border-color: var(--secondary);
      outline: none;
    }

    /* Sticky CTA Bar */
    .sticky-bar {
      position: fixed;
      bottom: -80px;
      left: 0;
      right: 0;
      height: 70px;
      background: #0B192C;
      border-top: 2px solid var(--accent);
      z-index: 1000;
      display: flex;
      align-items: center;
      transition: bottom 0.3s ease;
      box-shadow: 0 -4px 16px rgba(0,0,0,0.2);
    }
    .sticky-bar.show {
      bottom: 0;
    }
    .sticky-bar-content {
      display: flex;
      justify-content: space-between;
      align-items: center;
      width: 100%;
    }
    .sticky-text {
      color: #FFFFFF;
      font-weight: 600;
      font-size: 15px;
    }

    /* Footer */
    .site-footer {
      background: #060E18;
      color: #64748B;
      padding: 70px 0 30px;
      font-size: 13px;
      border-top: 1px solid rgba(255,255,255,0.08);
    }
    .footer-title {
      color: #FFFFFF;
      font-size: 15px;
      font-weight: 700;
      margin-bottom: 16px;
    }
    .footer-links {
      list-style: none;
      margin: 0;
      padding: 0;
    }
    .footer-links li {
      margin-bottom: 10px;
    }
    .footer-links a {
      color: #94A3B8;
    }
    .footer-links a:hover {
      color: #FFFFFF;
    }
    .footer-bottom {
      margin-top: 50px;
      padding-top: 24px;
      border-top: 1px solid rgba(255,255,255,0.06);
      text-align: center;
    }

    /* Responsive adjustments */
    @media (max-width: 1024px) {
      .hero-h1 { font-size: 32px; }
      .section-title { font-size: 26px; }
      section { padding: 64px 0; }
    }
    @media (max-width: 768px) {
      .header-top-right .hotline { display: none; }
      .hero-h1 { font-size: 26px; }
      .metric-num { font-size: 28px; }
      .timeline-steps { flex-direction: column; gap: 20px; }
      .timeline-step::before { display: none; }
      .sticky-text { display: none; }
      .sticky-bar-content { justify-content: center; }
      section { padding: 50px 0; }
      .story-wrapper { padding: 24px; }
    }