/* roulang page: index */
:root {
      --primary: #1E40AF;
      --primary-hover: #1D4ED8;
      --secondary: #F59E0B;
      --secondary-hover: #D97706;
      --teal: #0D9488;
      --bg-light: #F8FAFC;
      --bg-white: #FFFFFF;
      --bg-dark: #0F172A;
      --bg-darker: #020617;
      --text-main: #0F172A;
      --text-muted: #334155;
      --text-light: #64748B;
      --border-color: #E2E8F0;
      --border-dark: #1E293B;
      --radius-sm: 6px;
      --radius-md: 12px;
      --radius-lg: 18px;
      --shadow-sm: 0 1px 3px rgba(0,0,0,0.06);
      --shadow-md: 0 4px 20px -2px rgba(0,0,0,0.06);
      --shadow-lg: 0 10px 25px -5px rgba(0,0,0,0.1);
      --font-stack: -apple-system, BlinkMacSystemFont, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
    }

    * {
      box-sizing: border-box;
      margin: 0;
      padding: 0;
    }

    body {
      font-family: var(--font-stack);
      font-size: 16px;
      line-height: 1.65;
      color: var(--text-main);
      background-color: var(--bg-light);
      -webkit-font-smoothing: antialiased;
    }

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

    img {
      max-width: 100%;
      height: auto;
      display: block;
    }

    button, input, select, textarea {
      font-family: inherit;
      font-size: inherit;
    }

    .container {
      width: 100%;
      max-width: 1280px;
      margin-left: auto;
      margin-right: auto;
      padding-left: 20px;
      padding-right: 20px;
    }

    /* 顶部服务小栏 */
    .top-bar {
      background-color: var(--bg-dark);
      color: #94A3B8;
      font-size: 13px;
      padding: 8px 0;
      border-bottom: 1px solid var(--border-dark);
    }
    .top-bar-inner {
      display: flex;
      justify-content: space-between;
      align-items: center;
    }
    .top-meta span {
      margin-right: 20px;
    }

    /* 主导航 */
    .site-header {
      background-color: #ffffff;
      position: sticky;
      top: 0;
      z-index: 100;
      box-shadow: 0 2px 10px rgba(0,0,0,0.05);
      border-bottom: 1px solid var(--border-color);
    }
    .nav-inner {
      display: flex;
      justify-content: space-between;
      align-items: center;
      height: 72px;
    }
    .brand-logo {
      display: flex;
      align-items: center;
      gap: 10px;
      font-size: 22px;
      font-weight: 700;
      color: var(--primary);
      letter-spacing: -0.5px;
    }
    .brand-logo-mark {
      background: var(--primary);
      color: #fff;
      width: 36px;
      height: 36px;
      display: flex;
      align-items: center;
      justify-content: center;
      border-radius: var(--radius-sm);
      font-weight: 800;
    }
    .nav-menu {
      display: flex;
      gap: 28px;
      list-style: none;
    }
    .nav-menu a {
      font-size: 15px;
      font-weight: 500;
      color: var(--text-muted);
      padding: 8px 0;
      position: relative;
    }
    .nav-menu a:hover, .nav-menu a.active {
      color: var(--primary);
    }
    .nav-menu a.active::after {
      content: "";
      position: absolute;
      bottom: 0;
      left: 0;
      width: 100%;
      height: 2px;
      background: var(--primary);
    }
    .nav-cta {
      display: flex;
      align-items: center;
      gap: 12px;
    }

    /* 按钮规范 */
    .btn {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      padding: 10px 22px;
      font-size: 15px;
      font-weight: 600;
      border-radius: var(--radius-sm);
      cursor: pointer;
      border: 1px solid transparent;
      transition: all 0.25s ease;
      white-space: nowrap;
    }
    .btn-primary {
      background-color: var(--primary);
      color: #ffffff;
    }
    .btn-primary:hover {
      background-color: var(--primary-hover);
      transform: translateY(-1px);
      box-shadow: 0 4px 12px rgba(30, 64, 175, 0.25);
    }
    .btn-amber {
      background-color: var(--secondary);
      color: #ffffff;
    }
    .btn-amber:hover {
      background-color: var(--secondary-hover);
      transform: translateY(-1px);
      box-shadow: 0 4px 12px rgba(245, 158, 11, 0.3);
    }
    .btn-outline {
      background-color: transparent;
      border-color: var(--border-color);
      color: var(--text-muted);
    }
    .btn-outline:hover {
      border-color: var(--primary);
      color: var(--primary);
      background-color: #EFF6FF;
    }

    /* 移动端菜单按钮 */
    .menu-toggle {
      display: none;
      background: none;
      border: none;
      cursor: pointer;
      padding: 6px;
    }
    .menu-toggle span {
      display: block;
      width: 24px;
      height: 2px;
      background: var(--text-main);
      margin: 5px 0;
      transition: 0.3s;
    }

    /* 通用板块规范 */
    .section-wrap {
      padding: 85px 0;
      position: relative;
    }
    .section-white {
      background-color: var(--bg-white);
    }
    .section-gray {
      background-color: var(--bg-light);
    }
    .section-dark {
      background-color: var(--bg-dark);
      color: #ffffff;
    }
    .section-header {
      margin-bottom: 50px;
    }
    .section-header.text-center {
      text-align: center;
      max-width: 820px;
      margin-left: auto;
      margin-right: auto;
    }
    .section-badge {
      display: inline-block;
      padding: 4px 12px;
      background-color: #DBEAFE;
      color: var(--primary);
      font-size: 13px;
      font-weight: 600;
      border-radius: 20px;
      margin-bottom: 12px;
      letter-spacing: 0.5px;
    }
    .section-badge.badge-amber {
      background-color: #FEF3C7;
      color: #B45309;
    }
    .section-badge.badge-dark {
      background-color: rgba(255,255,255,0.1);
      color: #38BDF8;
    }
    .section-title {
      font-size: 32px;
      font-weight: 700;
      line-height: 1.3;
      margin-bottom: 16px;
      color: inherit;
    }
    .section-desc {
      font-size: 16px;
      color: var(--text-light);
      line-height: 1.7;
    }
    .section-dark .section-desc {
      color: #94A3B8;
    }

    /* 首屏对比舞台 (Hero) */
    .hero-compare {
      background: linear-gradient(180deg, #EFF6FF 0%, #FFFFFF 100%);
      padding: 60px 0 80px 0;
      border-bottom: 1px solid var(--border-color);
    }
    .hero-meta-row {
      text-align: center;
      max-width: 900px;
      margin: 0 auto 40px auto;
    }
    .hero-meta-row h1 {
      font-size: 40px;
      font-weight: 800;
      line-height: 1.25;
      color: var(--text-main);
      margin-bottom: 20px;
      letter-spacing: -0.5px;
    }
    .hero-meta-row p {
      font-size: 17px;
      color: var(--text-muted);
      line-height: 1.75;
      margin-bottom: 28px;
    }
    .hero-cta-group {
      display: flex;
      justify-content: center;
      gap: 16px;
      margin-bottom: 35px;
    }
    .compare-container {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 24px;
      background: #FFFFFF;
      padding: 24px;
      border-radius: var(--radius-lg);
      box-shadow: var(--shadow-lg);
      border: 1px solid var(--border-color);
    }
    .compare-card {
      border-radius: var(--radius-md);
      padding: 30px;
      position: relative;
    }
    .card-before {
      background: #FFF7ED;
      border: 1px dashed #FDBA74;
    }
    .card-after {
      background: #F0FDF4;
      border: 2px solid #86EFAC;
    }
    .compare-tag {
      display: inline-block;
      font-size: 12px;
      font-weight: 700;
      padding: 3px 10px;
      border-radius: 4px;
      margin-bottom: 16px;
    }
    .tag-before {
      background: #FFEDD5;
      color: #9A3412;
    }
    .tag-after {
      background: #DCFCE7;
      color: #166534;
    }
    .compare-card h3 {
      font-size: 20px;
      font-weight: 700;
      margin-bottom: 16px;
    }
    .compare-list {
      list-style: none;
    }
    .compare-list li {
      position: relative;
      padding-left: 24px;
      margin-bottom: 14px;
      font-size: 15px;
      color: var(--text-muted);
    }
    .card-before .compare-list li::before {
      content: "✕";
      position: absolute;
      left: 0;
      color: #EA580C;
      font-weight: bold;
    }
    .card-after .compare-list li::before {
      content: "✓";
      position: absolute;
      left: 0;
      color: #16A34A;
      font-weight: bold;
    }

    /* 左右分栏流 (资讯流 vs 热榜) */
    .stream-split-grid {
      display: grid;
      grid-template-columns: 2fr 1fr;
      gap: 36px;
    }
    .stream-item {
      display: flex;
      gap: 20px;
      background: var(--bg-white);
      padding: 20px;
      border-radius: var(--radius-md);
      border: 1px solid var(--border-color);
      margin-bottom: 20px;
      box-shadow: var(--shadow-sm);
      transition: transform 0.25s ease;
    }
    .stream-item:hover {
      transform: translateY(-3px);
      box-shadow: var(--shadow-md);
    }
    .stream-thumb {
      width: 220px;
      height: 140px;
      flex-shrink: 0;
      border-radius: var(--radius-sm);
      overflow: hidden;
      background: #E2E8F0;
    }
    .stream-thumb img {
      width: 100%;
      height: 100%;
      object-fit: cover;
    }
    .stream-content {
      display: flex;
      flex-direction: column;
      justify-content: center;
    }
    .stream-meta {
      font-size: 13px;
      color: var(--text-light);
      margin-bottom: 8px;
    }
    .stream-title {
      font-size: 18px;
      font-weight: 700;
      color: var(--text-main);
      margin-bottom: 8px;
    }
    .stream-desc {
      font-size: 14px;
      color: var(--text-muted);
      line-height: 1.6;
    }

    .rank-widget {
      background: var(--bg-white);
      border-radius: var(--radius-md);
      padding: 24px;
      border: 1px solid var(--border-color);
      box-shadow: var(--shadow-sm);
    }
    .rank-title {
      font-size: 18px;
      font-weight: 700;
      padding-bottom: 14px;
      border-bottom: 1px solid var(--border-color);
      margin-bottom: 16px;
      display: flex;
      align-items: center;
      justify-content: space-between;
    }
    .rank-list {
      list-style: none;
    }
    .rank-item {
      display: flex;
      gap: 14px;
      margin-bottom: 16px;
      align-items: flex-start;
    }
    .rank-num {
      width: 24px;
      height: 24px;
      border-radius: 4px;
      background: #E2E8F0;
      color: var(--text-muted);
      font-size: 12px;
      font-weight: 700;
      display: flex;
      align-items: center;
      justify-content: center;
      flex-shrink: 0;
    }
    .rank-item:nth-child(1) .rank-num { background: #EF4444; color: #fff; }
    .rank-item:nth-child(2) .rank-num { background: #F97316; color: #fff; }
    .rank-item:nth-child(3) .rank-num { background: #FBBF24; color: #fff; }
    .rank-text h4 {
      font-size: 14px;
      font-weight: 600;
      margin-bottom: 4px;
      line-height: 1.4;
    }
    .rank-text p {
      font-size: 12px;
      color: var(--text-light);
    }

    /* 专题横向条 */
    .feature-strip {
      background: #1E293B;
      color: #fff;
      padding: 30px;
      border-radius: var(--radius-lg);
      display: flex;
      align-items: center;
      justify-content: space-between;
      gap: 24px;
      background-size: cover;
      background-position: center;
      position: relative;
      overflow: hidden;
    }
    .strip-overlay {
      position: absolute;
      inset: 0;
      background: linear-gradient(90deg, rgba(15, 23, 42, 0.95) 0%, rgba(15, 23, 42, 0.75) 100%);
      z-index: 1;
    }
    .strip-content {
      position: relative;
      z-index: 2;
      max-width: 700px;
    }
    .strip-content h3 {
      font-size: 24px;
      margin-bottom: 10px;
    }
    .strip-content p {
      font-size: 15px;
      color: #CBD5E1;
      line-height: 1.6;
    }
    .strip-action {
      position: relative;
      z-index: 2;
      flex-shrink: 0;
    }

    /* 网格通用布局 (优势/功能/案例等) */
    .grid-3 {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }
    .grid-4 {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 20px;
    }
    .grid-2 {
      display: grid;
      grid-template-columns: repeat(2, 1fr);
      gap: 30px;
    }

    /* 卡片体系 */
    .ui-card {
      background: var(--bg-white);
      border-radius: var(--radius-md);
      border: 1px solid var(--border-color);
      padding: 28px;
      box-shadow: var(--shadow-sm);
      transition: all 0.25s ease;
    }
    .ui-card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-md);
      border-color: #CBD5E1;
    }
    .card-icon-box {
      width: 48px;
      height: 48px;
      border-radius: var(--radius-sm);
      background: #EFF6FF;
      color: var(--primary);
      display: flex;
      align-items: center;
      justify-content: center;
      font-size: 20px;
      font-weight: 700;
      margin-bottom: 18px;
    }
    .ui-card h4 {
      font-size: 18px;
      font-weight: 700;
      margin-bottom: 12px;
      color: var(--text-main);
    }
    .ui-card p {
      font-size: 14px;
      color: var(--text-muted);
      line-height: 1.65;
    }

    /* 架构图文区 */
    .arch-block {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 40px;
      align-items: center;
    }
    .arch-img-wrap {
      border-radius: var(--radius-lg);
      overflow: hidden;
      box-shadow: var(--shadow-lg);
      border: 1px solid var(--border-color);
    }
    .tech-metric-pill {
      display: inline-flex;
      align-items: center;
      gap: 8px;
      background: #EFF6FF;
      border: 1px solid #BFDBFE;
      padding: 6px 14px;
      border-radius: 20px;
      font-size: 13px;
      color: var(--primary);
      font-weight: 600;
      margin-top: 15px;
    }

    /* 量化指标条 */
    .metrics-bar {
      background: var(--primary);
      color: #ffffff;
      padding: 50px 0;
      border-radius: var(--radius-lg);
      margin: 40px 0;
    }
    .metrics-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      text-align: center;
      gap: 20px;
    }
    .metric-item .val {
      font-size: 40px;
      font-weight: 800;
      line-height: 1.1;
      margin-bottom: 8px;
      color: #FCD34D;
    }
    .metric-item .lbl {
      font-size: 15px;
      color: #E0E7FF;
      font-weight: 500;
    }

    /* 方案选型 (Pricing) */
    .pricing-card {
      background: var(--bg-white);
      border-radius: var(--radius-lg);
      border: 1px solid var(--border-color);
      padding: 36px 28px;
      position: relative;
      display: flex;
      flex-direction: column;
      box-shadow: var(--shadow-sm);
    }
    .pricing-card.featured {
      border: 2px solid var(--primary);
      box-shadow: var(--shadow-lg);
      transform: scale(1.03);
      z-index: 2;
    }
    .pricing-badge {
      position: absolute;
      top: -14px;
      left: 50%;
      transform: translateX(-50%);
      background: var(--primary);
      color: #ffffff;
      padding: 4px 14px;
      font-size: 12px;
      font-weight: 700;
      border-radius: 20px;
    }
    .price-val {
      font-size: 32px;
      font-weight: 800;
      color: var(--text-main);
      margin: 15px 0;
    }
    .price-val span {
      font-size: 14px;
      color: var(--text-light);
      font-weight: 400;
    }
    .pricing-features {
      list-style: none;
      margin: 20px 0 30px 0;
      flex-grow: 1;
    }
    .pricing-features li {
      font-size: 14px;
      color: var(--text-muted);
      margin-bottom: 12px;
      display: flex;
      align-items: center;
      gap: 10px;
    }
    .pricing-features li span {
      color: var(--teal);
      font-weight: bold;
    }

    /* 常见问题 (手风琴) */
    .faq-wrapper {
      max-width: 860px;
      margin: 0 auto;
    }
    .faq-item {
      background: var(--bg-white);
      border: 1px solid var(--border-color);
      border-radius: var(--radius-md);
      margin-bottom: 14px;
      overflow: hidden;
      box-shadow: var(--shadow-sm);
    }
    .faq-question {
      padding: 20px 24px;
      font-size: 16px;
      font-weight: 700;
      cursor: pointer;
      display: flex;
      justify-content: space-between;
      align-items: center;
      background: #ffffff;
      list-style: none;
    }
    .faq-question::-webkit-details-marker {
      display: none;
    }
    .faq-question::after {
      content: "+";
      font-size: 20px;
      color: var(--text-light);
      font-weight: 400;
      transition: transform 0.25s ease;
    }
    details[open] .faq-question::after {
      content: "−";
    }
    .faq-answer {
      padding: 0 24px 22px 24px;
      font-size: 14.5px;
      color: var(--text-muted);
      line-height: 1.7;
      border-top: 1px solid #F1F5F9;
      padding-top: 16px;
    }

    /* 底部收口行动区 */
    .cta-banner {
      background: linear-gradient(135deg, #1E40AF 0%, #1E3A8A 100%);
      color: #fff;
      padding: 70px 0;
      text-align: center;
    }
    .cta-banner h2 {
      font-size: 32px;
      font-weight: 800;
      margin-bottom: 16px;
    }
    .cta-banner p {
      font-size: 16px;
      color: #DBEAFE;
      max-width: 680px;
      margin: 0 auto 30px auto;
    }
    .cta-form {
      display: flex;
      justify-content: center;
      gap: 12px;
      max-width: 520px;
      margin: 0 auto;
    }
    .cta-input {
      flex: 1;
      padding: 12px 18px;
      border-radius: var(--radius-sm);
      border: none;
      outline: none;
    }

    /* 合作与媒体背书 */
    .partner-flex {
      display: flex;
      flex-wrap: wrap;
      justify-content: center;
      gap: 30px 45px;
      align-items: center;
      opacity: 0.75;
    }
    .partner-brand {
      font-size: 18px;
      font-weight: 700;
      color: #64748B;
      letter-spacing: 1px;
    }

    /* 页脚 */
    .site-footer {
      background: var(--bg-darker);
      color: #94A3B8;
      padding: 70px 0 25px 0;
      font-size: 14px;
      border-top: 1px solid var(--border-dark);
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1.5fr;
      gap: 40px;
      margin-bottom: 50px;
    }
    .footer-col h4 {
      color: #F8FAFC;
      font-size: 16px;
      font-weight: 700;
      margin-bottom: 20px;
    }
    .footer-links {
      list-style: none;
    }
    .footer-links li {
      margin-bottom: 10px;
    }
    .footer-links a:hover {
      color: #38BDF8;
    }
    .footer-bottom {
      border-top: 1px solid var(--border-dark);
      padding-top: 25px;
      display: flex;
      justify-content: space-between;
      align-items: center;
      font-size: 13px;
    }

    /* 响应式断点 */
    @media (max-width: 1024px) {
      .grid-4 { grid-template-columns: repeat(2, 1fr); }
      .metrics-grid { grid-template-columns: repeat(2, 1fr); gap: 30px; }
      .stream-split-grid { grid-template-columns: 1fr; }
      .pricing-card.featured { transform: none; }
      .footer-grid { grid-template-columns: 1fr 1fr; }
    }

    @media (max-width: 768px) {
      .top-bar { display: none; }
      .nav-menu { display: none; }
      .menu-toggle { display: block; }
      .hero-meta-row h1 { font-size: 28px; }
      .compare-container { grid-template-columns: 1fr; }
      .grid-3 { grid-template-columns: 1fr; }
      .grid-2 { grid-template-columns: 1fr; }
      .arch-block { grid-template-columns: 1fr; }
      .feature-strip { flex-direction: column; text-align: center; }
      .metrics-grid { grid-template-columns: 1fr 1fr; }
      .cta-form { flex-direction: column; }
      .footer-grid { grid-template-columns: 1fr; gap: 30px; }
      .footer-bottom { flex-direction: column; gap: 12px; text-align: center; }
      .stream-item { flex-direction: column; }
      .stream-thumb { width: 100%; height: 180px; }
    }

    @media (max-width: 520px) {
      .hero-cta-group { flex-direction: column; }
      .metrics-grid { grid-template-columns: 1fr; }
      .grid-4 { grid-template-columns: 1fr; }
    }