/* roulang page: index */
:root {
      --primary: #1E242B;
      --primary-light: #2C353F;
      --accent: #00D287;
      --accent-hover: #00B775;
      --accent-dim: rgba(0, 210, 135, 0.12);
      --secondary: #4A5568;
      --cyan: #0E86D4;
      --dark-bg: #0B0E14;
      --dark-card: #141923;
      --light-bg: #F4F6F8;
      --white: #FFFFFF;
      --text-main: #1A202C;
      --text-muted: #64748B;
      --border-light: rgba(0, 0, 0, 0.08);
      --border-dark: rgba(255, 255, 255, 0.12);
      --radius: 6px;
      --shadow-sm: 0 2px 8px rgba(0, 20, 40, 0.04);
      --shadow-card: 0 12px 30px -10px rgba(0, 20, 40, 0.08);
      --font-mono: "DIN Alternate", "Inter", -apple-system, monospace;
    }
    * {
      box-sizing: border-box;
      margin: 0;
      padding: 0;
    }
    html {
      scroll-behavior: smooth;
      font-size: 16px;
    }
    body {
      font-family: system-ui, -apple-system, "PingFang SC", "Microsoft YaHei", sans-serif;
      background-color: var(--light-bg);
      color: var(--text-main);
      line-height: 1.65;
      -webkit-font-smoothing: antialiased;
    }
    a {
      text-decoration: none;
      color: inherit;
    }
    img {
      max-width: 100%;
      height: auto;
      display: block;
    }
    .container {
      width: 100%;
      max-width: 1240px;
      margin: 0 auto;
      padding: 0 24px;
    }
    .top-bar {
      background: var(--dark-bg);
      color: #94A3B8;
      font-size: 12px;
      padding: 8px 0;
      border-bottom: 1px solid rgba(255, 255, 255, 0.06);
    }
    .top-bar-inner {
      display: flex;
      justify-content: space-between;
      align-items: center;
      flex-wrap: wrap;
      gap: 12px;
    }
    .top-bar-links a {
      color: #94A3B8;
      margin-left: 18px;
      transition: color 0.2s;
    }
    .top-bar-links a:hover {
      color: var(--accent);
    }
    .navbar {
      background: rgba(30, 36, 43, 0.96);
      backdrop-filter: blur(12px);
      position: sticky;
      top: 0;
      z-index: 1000;
      border-bottom: 1px solid rgba(255, 255, 255, 0.08);
    }
    .nav-inner {
      display: flex;
      align-items: center;
      justify-content: space-between;
      height: 72px;
    }
    .logo {
      font-size: 20px;
      font-weight: 700;
      color: var(--white);
      letter-spacing: 0.5px;
      display: flex;
      align-items: center;
      gap: 10px;
    }
    .logo-badge {
      font-size: 11px;
      background: var(--accent);
      color: var(--dark-bg);
      padding: 2px 7px;
      border-radius: 4px;
      font-weight: 700;
      text-transform: uppercase;
    }
    .nav-menu {
      display: flex;
      align-items: center;
      gap: 28px;
      list-style: none;
    }
    .nav-menu a {
      color: #CBD5E1;
      font-size: 14px;
      font-weight: 500;
      transition: color 0.2s;
      padding: 6px 0;
    }
    .nav-menu a:hover, .nav-menu a.active {
      color: var(--accent);
    }
    .btn {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      padding: 11px 22px;
      font-size: 14px;
      font-weight: 600;
      border-radius: var(--radius);
      transition: all 0.25s ease;
      cursor: pointer;
      border: 1px solid transparent;
      text-align: center;
    }
    .btn-primary {
      background-color: var(--accent);
      color: var(--dark-bg);
    }
    .btn-primary:hover {
      background-color: var(--accent-hover);
      box-shadow: 0 4px 16px rgba(0, 210, 135, 0.35);
    }
    .btn-outline {
      border-color: rgba(255, 255, 255, 0.25);
      color: var(--white);
      background: rgba(255, 255, 255, 0.04);
    }
    .btn-outline:hover {
      border-color: var(--accent);
      color: var(--accent);
    }
    .btn-dark {
      background-color: var(--primary);
      color: var(--white);
    }
    .btn-dark:hover {
      background-color: #000;
    }
    .section {
      padding: 90px 0;
      position: relative;
    }
    .section-light {
      background: var(--white);
    }
    .section-alt {
      background: var(--light-bg);
    }
    .section-dark {
      background: var(--dark-bg);
      color: var(--white);
    }
    .section-header {
      margin-bottom: 56px;
    }
    .section-header.text-center {
      text-align: center;
      max-width: 820px;
      margin-left: auto;
      margin-right: auto;
    }
    .section-tag {
      display: inline-block;
      font-size: 12px;
      font-weight: 700;
      letter-spacing: 1px;
      color: var(--cyan);
      background: rgba(14, 134, 212, 0.08);
      padding: 4px 12px;
      border-radius: 4px;
      margin-bottom: 12px;
      text-transform: uppercase;
    }
    .section-dark .section-tag {
      color: var(--accent);
      background: var(--accent-dim);
    }
    .section-title {
      font-size: 32px;
      font-weight: 700;
      line-height: 1.3;
      margin-bottom: 16px;
      color: var(--text-main);
    }
    .section-dark .section-title {
      color: var(--white);
    }
    .section-desc {
      font-size: 15px;
      color: var(--text-muted);
      max-width: 780px;
      line-height: 1.7;
    }
    .section-dark .section-desc {
      color: #94A3B8;
    }
    /* Hero Coupon-Wall Blueprint */
    .hero-wall {
      background-color: var(--dark-bg);
      background-image: linear-gradient(rgba(11, 14, 20, 0.82), rgba(11, 14, 20, 0.94)), url('/assets/images/1268a1be2047d7c8.webp');
      background-size: cover;
      background-position: center;
      padding: 90px 0 100px;
      color: var(--white);
      border-bottom: 1px solid rgba(255, 255, 255, 0.06);
    }
    .hero-wall-grid {
      display: grid;
      grid-template-columns: 1.15fr 0.85fr;
      gap: 48px;
      align-items: center;
    }
    .hero-h1 {
      font-size: 40px;
      font-weight: 800;
      line-height: 1.25;
      margin-bottom: 20px;
      letter-spacing: -0.5px;
    }
    .hero-lead {
      font-size: 16px;
      color: #CBD5E1;
      line-height: 1.75;
      margin-bottom: 32px;
    }
    .coupon-card-main {
      background: linear-gradient(135deg, #18202C 0%, #101620 100%);
      border: 1px dashed var(--accent);
      border-radius: 8px;
      padding: 32px;
      position: relative;
      box-shadow: 0 20px 40px rgba(0, 0, 0, 0.5);
    }
    .coupon-head {
      display: flex;
      justify-content: space-between;
      align-items: baseline;
      border-bottom: 1px solid rgba(255, 255, 255, 0.08);
      padding-bottom: 18px;
      margin-bottom: 20px;
    }
    .coupon-value {
      font-family: var(--font-mono);
      font-size: 42px;
      font-weight: 700;
      color: var(--accent);
    }
    .coupon-value span {
      font-size: 16px;
      color: #CBD5E1;
      font-weight: normal;
      margin-left: 6px;
    }
    .coupon-tier {
      font-size: 13px;
      color: #94A3B8;
      background: rgba(255, 255, 255, 0.06);
      padding: 4px 10px;
      border-radius: 4px;
    }
    .coupon-details li {
      font-size: 14px;
      color: #CBD5E1;
      margin-bottom: 10px;
      list-style: none;
      display: flex;
      align-items: center;
      gap: 8px;
    }
    .coupon-details li::before {
      content: "✔";
      color: var(--accent);
      font-size: 12px;
    }
    .coupon-actions {
      margin-top: 24px;
      display: flex;
      gap: 14px;
    }
    /* Grid Coupons */
    .coupon-wall-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
      margin-top: 36px;
    }
    .coupon-item {
      background: var(--dark-card);
      border: 1px solid var(--border-dark);
      border-radius: 6px;
      padding: 24px;
      display: flex;
      flex-direction: column;
      justify-content: space-between;
      transition: transform 0.2s, border-color 0.2s;
    }
    .coupon-item:hover {
      transform: translateY(-4px);
      border-color: var(--accent);
    }
    .coupon-item-title {
      font-size: 17px;
      font-weight: 700;
      color: var(--white);
      margin-bottom: 8px;
    }
    .coupon-item-cond {
      font-size: 13px;
      color: #94A3B8;
      margin-bottom: 18px;
    }
    .coupon-item-worth {
      font-family: var(--font-mono);
      font-size: 24px;
      color: var(--accent);
      font-weight: 700;
      margin-bottom: 18px;
    }
    /* Metrics Dashboard */
    .metrics-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 24px;
    }
    .metric-card {
      background: var(--white);
      border: 1px solid var(--border-light);
      border-radius: var(--radius);
      padding: 30px 24px;
      box-shadow: var(--shadow-sm);
      position: relative;
      overflow: hidden;
      border-top: 3px solid var(--primary);
    }
    .metric-card.highlight {
      border-top-color: var(--accent);
    }
    .metric-num {
      font-family: var(--font-mono);
      font-size: 38px;
      font-weight: 700;
      color: var(--primary);
      line-height: 1.1;
      margin-bottom: 8px;
    }
    .metric-label {
      font-size: 15px;
      font-weight: 600;
      color: var(--text-main);
      margin-bottom: 6px;
    }
    .metric-desc {
      font-size: 13px;
      color: var(--text-muted);
      line-height: 1.5;
    }
    /* System Matrix */
    .matrix-layout {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 40px;
      align-items: center;
    }
    .matrix-img-wrap {
      border-radius: var(--radius);
      overflow: hidden;
      border: 1px solid var(--border-light);
      box-shadow: var(--shadow-card);
    }
    .matrix-layers {
      display: flex;
      flex-direction: column;
      gap: 18px;
    }
    .layer-card {
      background: var(--white);
      border: 1px solid var(--border-light);
      border-left: 4px solid var(--cyan);
      padding: 20px;
      border-radius: var(--radius);
    }
    .layer-title {
      font-size: 16px;
      font-weight: 700;
      color: var(--primary);
      margin-bottom: 6px;
      display: flex;
      justify-content: space-between;
      align-items: center;
    }
    .layer-badge {
      font-size: 11px;
      font-family: var(--font-mono);
      background: #E2E8F0;
      padding: 2px 8px;
      border-radius: 4px;
      color: #334155;
    }
    .layer-text {
      font-size: 14px;
      color: var(--text-muted);
      line-height: 1.6;
    }
    /* Core Advantages */
    .grid-3 {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 28px;
    }
    .adv-card {
      background: var(--white);
      border: 1px solid var(--border-light);
      border-radius: var(--radius);
      padding: 30px;
      transition: all 0.25s ease;
      position: relative;
    }
    .adv-card:hover {
      border-color: var(--accent);
      box-shadow: var(--shadow-card);
      transform: translateY(-3px);
    }
    .adv-index {
      font-family: var(--font-mono);
      font-size: 13px;
      color: var(--cyan);
      font-weight: 700;
      margin-bottom: 12px;
      display: block;
    }
    .adv-title {
      font-size: 18px;
      font-weight: 700;
      color: var(--primary);
      margin-bottom: 10px;
    }
    .adv-text {
      font-size: 14px;
      color: var(--text-muted);
      line-height: 1.65;
    }
    /* Product Tier */
    .tier-card {
      background: var(--white);
      border: 1px solid var(--border-light);
      border-radius: var(--radius);
      padding: 36px 30px;
      display: flex;
      flex-direction: column;
      justify-content: space-between;
      position: relative;
    }
    .tier-card.featured {
      border: 2px solid var(--accent);
      box-shadow: var(--shadow-card);
    }
    .tier-flag {
      position: absolute;
      top: -12px;
      right: 24px;
      background: var(--accent);
      color: var(--dark-bg);
      font-size: 11px;
      font-weight: 700;
      padding: 3px 10px;
      border-radius: 4px;
      text-transform: uppercase;
    }
    .tier-name {
      font-size: 20px;
      font-weight: 700;
      color: var(--primary);
      margin-bottom: 8px;
    }
    .tier-summary {
      font-size: 14px;
      color: var(--text-muted);
      margin-bottom: 20px;
      min-height: 44px;
    }
    .tier-specs {
      border-top: 1px solid var(--border-light);
      border-bottom: 1px solid var(--border-light);
      padding: 20px 0;
      margin-bottom: 24px;
      list-style: none;
    }
    .tier-specs li {
      font-size: 13px;
      color: var(--text-main);
      margin-bottom: 10px;
      display: flex;
      justify-content: space-between;
    }
    .tier-specs li span:first-child {
      color: var(--text-muted);
    }
    /* Benchmark Table */
    .benchmark-table {
      width: 100%;
      border-collapse: collapse;
      background: var(--white);
      border-radius: var(--radius);
      overflow: hidden;
      box-shadow: var(--shadow-sm);
      border: 1px solid var(--border-light);
    }
    .benchmark-table th, .benchmark-table td {
      padding: 18px 24px;
      text-align: left;
      font-size: 14px;
    }
    .benchmark-table th {
      background: #F8FAFC;
      color: var(--primary);
      font-weight: 700;
      border-bottom: 1px solid var(--border-light);
    }
    .benchmark-table tr:not(:last-child) td {
      border-bottom: 1px solid #EDF2F7;
    }
    .benchmark-table td.highlight-col {
      background: rgba(0, 210, 135, 0.04);
      color: #0F5132;
      font-weight: 600;
    }
    /* Timeline / Milestones */
    .timeline {
      position: relative;
      border-left: 2px solid #E2E8F0;
      margin-left: 20px;
      padding-left: 30px;
    }
    .timeline-item {
      position: relative;
      margin-bottom: 36px;
    }
    .timeline-item::before {
      content: "";
      position: absolute;
      left: -37px;
      top: 4px;
      width: 12px;
      height: 12px;
      border-radius: 50%;
      background: var(--white);
      border: 3px solid var(--accent);
    }
    .timeline-date {
      font-family: var(--font-mono);
      font-size: 13px;
      font-weight: 700;
      color: var(--cyan);
      margin-bottom: 4px;
    }
    .timeline-title {
      font-size: 17px;
      font-weight: 700;
      color: var(--primary);
      margin-bottom: 6px;
    }
    .timeline-desc {
      font-size: 14px;
      color: var(--text-muted);
      line-height: 1.6;
    }
    /* Case Studies */
    .grid-2 {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 32px;
    }
    .case-card {
      background: var(--white);
      border: 1px solid var(--border-light);
      border-radius: var(--radius);
      overflow: hidden;
      box-shadow: var(--shadow-sm);
    }
    .case-img {
      height: 240px;
      overflow: hidden;
    }
    .case-img img {
      width: 100%;
      height: 100%;
      object-fit: cover;
      transition: transform 0.3s ease;
    }
    .case-card:hover .case-img img {
      transform: scale(1.03);
    }
    .case-body {
      padding: 28px;
    }
    .case-tag {
      font-size: 12px;
      color: var(--cyan);
      font-weight: 600;
      margin-bottom: 8px;
      display: inline-block;
    }
    .case-title {
      font-size: 19px;
      font-weight: 700;
      color: var(--primary);
      margin-bottom: 10px;
    }
    .case-desc {
      font-size: 14px;
      color: var(--text-muted);
      line-height: 1.65;
      margin-bottom: 16px;
    }
    .case-stat {
      display: flex;
      gap: 24px;
      padding-top: 14px;
      border-top: 1px solid #EDF2F7;
    }
    .case-stat-num {
      font-family: var(--font-mono);
      font-size: 20px;
      font-weight: 700;
      color: var(--primary);
    }
    .case-stat-label {
      font-size: 12px;
      color: var(--text-muted);
    }
    /* Assurance / Standards */
    .assurance-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 20px;
    }
    .assurance-item {
      background: var(--dark-card);
      border: 1px solid var(--border-dark);
      padding: 24px;
      border-radius: var(--radius);
      text-align: center;
    }
    .assurance-code {
      font-family: var(--font-mono);
      font-size: 14px;
      color: var(--accent);
      font-weight: 700;
      margin-bottom: 6px;
    }
    .assurance-name {
      font-size: 15px;
      font-weight: 600;
      color: var(--white);
      margin-bottom: 8px;
    }
    .assurance-detail {
      font-size: 12px;
      color: #94A3B8;
      line-height: 1.5;
    }
    /* News Cards */
    .news-card {
      background: var(--white);
      border: 1px solid var(--border-light);
      border-radius: var(--radius);
      padding: 26px;
      display: flex;
      flex-direction: column;
      justify-content: space-between;
    }
    .news-date {
      font-size: 12px;
      color: var(--text-muted);
      font-family: var(--font-mono);
      margin-bottom: 8px;
    }
    .news-title {
      font-size: 17px;
      font-weight: 700;
      color: var(--primary);
      margin-bottom: 10px;
      line-height: 1.4;
    }
    .news-snippet {
      font-size: 14px;
      color: var(--text-muted);
      line-height: 1.6;
      margin-bottom: 18px;
    }
    .news-link {
      font-size: 13px;
      font-weight: 600;
      color: var(--cyan);
      display: inline-flex;
      align-items: center;
      gap: 4px;
    }
    /* FAQ Accordion */
    .faq-wrapper {
      max-width: 900px;
      margin: 0 auto;
    }
    .faq-item {
      background: var(--white);
      border: 1px solid var(--border-light);
      border-radius: var(--radius);
      margin-bottom: 14px;
      overflow: hidden;
    }
    .faq-question {
      padding: 20px 24px;
      font-size: 16px;
      font-weight: 600;
      color: var(--text-main);
      cursor: pointer;
      display: flex;
      justify-content: space-between;
      align-items: center;
      user-select: none;
    }
    .faq-question::after {
      content: "+";
      font-size: 20px;
      color: var(--text-muted);
      transition: transform 0.2s;
    }
    .faq-item.active .faq-question::after {
      content: "−";
      color: var(--accent);
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease-out, padding 0.3s ease;
      background: #FBFCFE;
      color: var(--text-muted);
      font-size: 14px;
      line-height: 1.7;
      padding: 0 24px;
    }
    .faq-item.active .faq-answer {
      max-height: 300px;
      padding: 16px 24px 24px;
      border-top: 1px solid #EDF2F7;
    }
    /* Testimonials */
    .testi-card {
      background: var(--white);
      border: 1px solid var(--border-light);
      border-radius: var(--radius);
      padding: 30px;
      display: flex;
      flex-direction: column;
      justify-content: space-between;
    }
    .testi-stars {
      color: #F59E0B;
      font-size: 14px;
      margin-bottom: 14px;
    }
    .testi-text {
      font-size: 14px;
      color: var(--secondary);
      line-height: 1.7;
      margin-bottom: 20px;
      font-style: normal;
    }
    .testi-author {
      display: flex;
      align-items: center;
      gap: 12px;
      border-top: 1px solid #EDF2F7;
      padding-top: 14px;
    }
    .testi-avatar {
      width: 40px;
      height: 40px;
      border-radius: 50%;
      background: #E2E8F0;
      display: flex;
      align-items: center;
      justify-content: center;
      font-weight: 700;
      font-size: 14px;
      color: var(--primary);
    }
    .testi-name {
      font-size: 14px;
      font-weight: 700;
      color: var(--primary);
    }
    .testi-role {
      font-size: 12px;
      color: var(--text-muted);
    }
    /* Form Section */
    .conversion-box {
      background: linear-gradient(135deg, #18202C 0%, #10151E 100%);
      border: 1px solid rgba(255, 255, 255, 0.1);
      border-radius: 8px;
      padding: 50px 40px;
      color: var(--white);
      display: grid;
      grid-template-columns: 1fr 1.1fr;
      gap: 50px;
      align-items: center;
    }
    .form-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 16px;
    }
    .form-group.full {
      grid-column: span 2;
    }
    .form-group label {
      display: block;
      font-size: 13px;
      color: #94A3B8;
      margin-bottom: 6px;
    }
    .form-control {
      width: 100%;
      background: rgba(255, 255, 255, 0.06);
      border: 1px solid rgba(255, 255, 255, 0.15);
      border-radius: 4px;
      padding: 11px 14px;
      color: var(--white);
      font-size: 14px;
      outline: none;
      transition: border-color 0.2s;
    }
    .form-control:focus {
      border-color: var(--accent);
      background: rgba(255, 255, 255, 0.09);
    }
    /* Footer */
    .footer {
      background: #090B0F;
      color: #94A3B8;
      padding: 70px 0 30px;
      font-size: 13px;
      border-top: 1px solid rgba(255, 255, 255, 0.06);
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 1.5fr 1fr 1.2fr 1.3fr;
      gap: 40px;
      margin-bottom: 50px;
    }
    .footer-col h4 {
      color: var(--white);
      font-size: 15px;
      font-weight: 700;
      margin-bottom: 18px;
    }
    .footer-col p {
      line-height: 1.7;
      margin-bottom: 12px;
    }
    .footer-links {
      list-style: none;
    }
    .footer-links li {
      margin-bottom: 10px;
    }
    .footer-links a {
      color: #94A3B8;
      transition: color 0.2s;
    }
    .footer-links a:hover {
      color: var(--accent);
    }
    .footer-bottom {
      border-top: 1px solid rgba(255, 255, 255, 0.08);
      padding-top: 24px;
      display: flex;
      justify-content: space-between;
      align-items: center;
      flex-wrap: wrap;
      gap: 16px;
      font-size: 12px;
    }
    /* Mobile Menu Toggle */
    .menu-toggle {
      display: none;
      background: none;
      border: none;
      color: var(--white);
      font-size: 24px;
      cursor: pointer;
    }
    /* Responsive Breakpoints */
    @media (max-width: 1024px) {
      .hero-wall-grid, .matrix-layout, .conversion-box {
        grid-template-columns: 1fr;
      }
      .coupon-wall-grid, .grid-3 {
        grid-template-columns: repeat(2, 1fr);
      }
      .metrics-grid, .assurance-grid {
        grid-template-columns: repeat(2, 1fr);
      }
      .footer-grid {
        grid-template-columns: 1fr 1fr;
      }
    }
    @media (max-width: 768px) {
      .menu-toggle {
        display: block;
      }
      .nav-menu {
        display: none;
        position: absolute;
        top: 72px;
        left: 0;
        width: 100%;
        background: var(--primary);
        flex-direction: column;
        padding: 20px;
        border-bottom: 1px solid rgba(255, 255, 255, 0.1);
        gap: 16px;
      }
      .nav-menu.show {
        display: flex;
      }
      .top-bar-inner {
        flex-direction: column;
        align-items: flex-start;
      }
      .hero-h1 {
        font-size: 28px;
      }
      .section-title {
        font-size: 24px;
      }
      .coupon-wall-grid, .grid-3, .grid-2, .metrics-grid, .assurance-grid {
        grid-template-columns: 1fr;
      }
      .form-grid {
        grid-template-columns: 1fr;
      }
      .form-group.full {
        grid-column: span 1;
      }
      .footer-grid {
        grid-template-columns: 1fr;
      }
      .footer-bottom {
        flex-direction: column;
        align-items: flex-start;
      }
    }