/* roulang page: index */
:root {
      --primary: #4E6EF2;
      --primary-hover: #3A5AD9;
      --primary-light: rgba(78, 110, 242, 0.08);
      --primary-glow: rgba(78, 110, 242, 0.15);
      --success: #00B578;
      --warning: #FF9F0A;
      --danger: #FA5151;
      --text-main: #1F2329;
      --text-secondary: #86909C;
      --border-light: #E5E8EF;
      --bg-page: #F5F6FA;
      --bg-card: #FFFFFF;
      --shadow-sm: 0 2px 12px rgba(0, 0, 0, 0.04);
      --shadow-md: 0 4px 20px rgba(0, 0, 0, 0.08);
      --radius-card: 12px;
      --radius-btn: 8px;
      --radius-input: 24px;
      --radius-tag: 4px;
      --font-stack: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", "Helvetica Neue", sans-serif;
      --max-width: 1200px;
      --space-mobile: 20px;
      --space-tablet: 32px;
      --space-desktop: 40px;
    }

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

    html {
      scroll-behavior: smooth;
    }

    body {
      font-family: var(--font-stack);
      background-color: var(--bg-page);
      color: var(--text-main);
      line-height: 1.5;
      font-size: 16px;
      -webkit-font-smoothing: antialiased;
      -moz-osx-font-smoothing: grayscale;
    }

    a {
      text-decoration: none;
      color: inherit;
      transition: color 150ms ease;
    }

    a:hover {
      color: var(--primary);
    }

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

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

    .container {
      width: 100%;
      max-width: var(--max-width);
      margin: 0 auto;
      padding-left: var(--space-mobile);
      padding-right: var(--space-mobile);
    }

    @media (min-width: 768px) {
      .container {
        padding-left: var(--space-tablet);
        padding-right: var(--space-tablet);
      }
    }

    @media (min-width: 1025px) {
      .container {
        padding-left: var(--space-desktop);
        padding-right: var(--space-desktop);
      }
    }

    /* 导航 */
    .header {
      position: sticky;
      top: 0;
      z-index: 100;
      background-color: #FFFFFF;
      border-bottom: 1px solid var(--border-light);
      backdrop-filter: blur(8px);
      background-color: rgba(255, 255, 255, 0.92);
    }

    .nav {
      display: flex;
      align-items: center;
      justify-content: space-between;
      height: 64px;
      max-width: var(--max-width);
      margin: 0 auto;
      padding: 0 var(--space-mobile);
    }

    @media (min-width: 768px) {
      .nav {
        padding: 0 var(--space-tablet);
      }
    }

    @media (min-width: 1025px) {
      .nav {
        padding: 0 var(--space-desktop);
      }
    }

    .logo {
      font-weight: 700;
      font-size: 20px;
      color: var(--text-main);
      letter-spacing: -0.3px;
      white-space: nowrap;
    }

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

    .nav-links {
      display: none;
      gap: 28px;
      align-items: center;
    }

    @media (min-width: 1025px) {
      .nav-links {
        display: flex;
      }
    }

    .nav-link {
      font-size: 14px;
      color: var(--text-secondary);
      font-weight: 500;
      position: relative;
      padding: 4px 0;
      white-space: nowrap;
    }

    .nav-link:hover {
      color: var(--primary);
    }

    .nav-link.active {
      color: var(--primary);
    }

    .nav-link.active::after {
      content: '';
      position: absolute;
      bottom: -20px;
      left: 0;
      width: 100%;
      height: 2px;
      background-color: var(--primary);
    }

    .btn-primary {
      background-color: var(--primary);
      color: white;
      border: none;
      padding: 10px 22px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      font-size: 14px;
      cursor: pointer;
      transition: background-color 150ms ease, transform 150ms ease;
      white-space: nowrap;
      display: inline-block;
      text-align: center;
    }

    .btn-primary:hover {
      background-color: var(--primary-hover);
      color: white;
      transform: translateY(-1px);
    }

    .btn-secondary {
      background: transparent;
      border: 1px solid var(--border-light);
      color: var(--text-main);
      padding: 10px 22px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      font-size: 14px;
      cursor: pointer;
      transition: border-color 150ms ease, color 150ms ease;
      white-space: nowrap;
      display: inline-block;
      text-align: center;
    }

    .btn-secondary:hover {
      border-color: var(--primary);
      color: var(--primary);
    }

    .menu-toggle {
      display: flex;
      flex-direction: column;
      justify-content: space-around;
      width: 24px;
      height: 20px;
      background: transparent;
      border: none;
      cursor: pointer;
      padding: 0;
    }

    .menu-toggle span {
      display: block;
      width: 100%;
      height: 1.5px;
      background-color: var(--text-main);
      transition: 200ms ease;
      border-radius: 2px;
    }

    @media (min-width: 1025px) {
      .menu-toggle {
        display: none;
      }
    }

    .mobile-menu {
      display: none;
      position: fixed;
      top: 64px;
      left: 0;
      width: 100%;
      height: calc(100vh - 64px);
      background: white;
      flex-direction: column;
      padding: 32px 20px;
      gap: 24px;
      z-index: 99;
      box-shadow: 0 20px 30px rgba(0,0,0,0.05);
    }

    .mobile-menu.active {
      display: flex;
    }

    .mobile-menu .nav-link {
      font-size: 18px;
      color: var(--text-main);
      font-weight: 500;
    }

    .mobile-menu .btn-primary {
      width: 100%;
      margin-top: 16px;
      padding: 14px 0;
    }

    /* 板块通用 */
    section {
      padding-top: 80px;
      padding-bottom: 80px;
    }

    @media (min-width: 1025px) {
      section {
        padding-top: 120px;
        padding-bottom: 120px;
      }
    }

    .section-title {
      font-size: 24px;
      font-weight: 600;
      line-height: 1.4;
      text-align: center;
      margin-bottom: 16px;
      color: var(--text-main);
    }

    @media (min-width: 1025px) {
      .section-title {
        font-size: 32px;
      }
    }

    .section-subtitle {
      font-size: 16px;
      color: var(--text-secondary);
      text-align: center;
      max-width: 640px;
      margin: 0 auto 48px auto;
      line-height: 1.6;
    }

    /* Hero */
    .hero {
      background-color: #FFFFFF;
      padding-top: 80px;
      padding-bottom: 80px;
    }

    .hero-grid {
      display: flex;
      flex-direction: column;
      gap: 40px;
      align-items: center;
    }

    @media (min-width: 1025px) {
      .hero-grid {
        flex-direction: row;
        gap: 60px;
      }
    }

    .hero-content {
      flex: 1;
      text-align: left;
    }

    .hero h1 {
      font-size: 28px;
      font-weight: 700;
      line-height: 1.3;
      color: var(--text-main);
      margin-bottom: 20px;
    }

    @media (min-width: 1025px) {
      .hero h1 {
        font-size: 40px;
        line-height: 1.25;
      }
    }

    .hero p {
      font-size: 16px;
      color: var(--text-secondary);
      margin-bottom: 32px;
      line-height: 1.6;
    }

    .hero-actions {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
    }

    .hero-visual {
      flex: 1;
      width: 100%;
      min-height: 280px;
      background-image: url('/assets/images/backpic/back-1.webp');
      background-size: cover;
      background-position: center;
      border-radius: var(--radius-card);
      position: relative;
      overflow: hidden;
      box-shadow: var(--shadow-md);
    }

    .hero-visual::after {
      content: '';
      position: absolute;
      inset: 0;
      background: linear-gradient(135deg, rgba(78,110,242,0.08) 0%, rgba(255,255,255,0.9) 80%);
      pointer-events: none;
    }

    /* 特性卡片 */
    .features-grid {
      display: grid;
      grid-template-columns: 1fr;
      gap: 24px;
    }

    @media (min-width: 768px) {
      .features-grid {
        grid-template-columns: repeat(3, 1fr);
      }
    }

    .feature-card {
      background: var(--bg-card);
      border-radius: var(--radius-card);
      padding: 32px;
      box-shadow: var(--shadow-sm);
      border-left: 4px solid var(--primary);
      transition: transform 200ms ease, box-shadow 200ms ease;
      display: flex;
      flex-direction: column;
    }

    .feature-card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-md);
    }

    .feature-number {
      font-size: 32px;
      font-weight: 700;
      color: var(--primary);
      opacity: 0.15;
      margin-bottom: 12px;
      line-height: 1;
    }

    .feature-title {
      font-size: 18px;
      font-weight: 600;
      margin-bottom: 8px;
      color: var(--text-main);
    }

    .feature-desc {
      font-size: 14px;
      color: var(--text-secondary);
      line-height: 1.5;
      margin-bottom: 24px;
      flex: 1;
    }

    .progress-bar {
      width: 100%;
      height: 4px;
      background: #F0F1F5;
      border-radius: 2px;
      overflow: hidden;
    }

    .progress-fill {
      height: 100%;
      width: 0%;
      background: var(--primary);
      border-radius: 2px;
    }

    /* 数据看板 */
    .data-section {
      background-color: #F8F9FC;
    }

    .data-grid {
      display: grid;
      grid-template-columns: repeat(2, 1fr);
      gap: 20px;
    }

    @media (min-width: 768px) {
      .data-grid {
        grid-template-columns: repeat(4, 1fr);
      }
    }

    .data-card {
      background: var(--bg-card);
      border-radius: var(--radius-card);
      padding: 24px;
      text-align: center;
      box-shadow: var(--shadow-sm);
    }

    .data-number {
      font-size: 32px;
      font-weight: 700;
      color: var(--primary);
      margin-bottom: 8px;
    }

    .data-label {
      font-size: 14px;
      color: var(--text-secondary);
      margin-bottom: 8px;
    }

    .trend {
      font-size: 14px;
      font-weight: 600;
      display: flex;
      align-items: center;
      justify-content: center;
      gap: 4px;
    }

    .trend.up {
      color: var(--success);
    }

    .trend.down {
      color: var(--danger);
    }

    /* 对比卡片 */
    .compare-grid {
      display: grid;
      grid-template-columns: 1fr;
      gap: 24px;
    }

    @media (min-width: 768px) {
      .compare-grid {
        grid-template-columns: 1fr 1fr;
      }
    }

    .compare-card {
      background: var(--bg-card);
      border-radius: var(--radius-card);
      padding: 32px;
      box-shadow: var(--shadow-sm);
    }

    .compare-card.before {
      background: #F5F6FA;
    }

    .compare-card.after {
      background: white;
      border-left: 4px solid var(--primary);
    }

    .compare-title {
      font-size: 20px;
      font-weight: 600;
      margin-bottom: 20px;
    }

    .compare-list {
      list-style: none;
    }

    .compare-list li {
      display: flex;
      justify-content: space-between;
      padding: 12px 0;
      border-bottom: 1px solid #f0f0f0;
      font-size: 15px;
    }

    .compare-list li:last-child {
      border-bottom: none;
    }

    .old-value {
      text-decoration: line-through;
      color: var(--text-secondary);
    }

    .new-value {
      font-weight: 700;
      color: var(--primary);
    }

    /* FAQ */
    .faq-list {
      display: flex;
      flex-direction: column;
      gap: 12px;
      max-width: 800px;
      margin: 0 auto;
    }

    .faq-item {
      background: var(--bg-card);
      border-radius: var(--radius-card);
      box-shadow: var(--shadow-sm);
      overflow: hidden;
      transition: 200ms ease;
    }

    .faq-question {
      width: 100%;
      background: transparent;
      border: none;
      padding: 20px 24px;
      display: flex;
      justify-content: space-between;
      align-items: center;
      font-weight: 500;
      font-size: 16px;
      cursor: pointer;
      color: var(--text-main);
    }

    .faq-icon {
      font-size: 20px;
      font-weight: 300;
      color: var(--primary);
      transition: 150ms ease;
    }

    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 250ms ease;
      background: #F9FAFB;
      color: var(--text-secondary);
      font-size: 14px;
      line-height: 1.6;
    }

    .faq-answer p {
      padding: 0 24px 20px;
    }

    .faq-item.open .faq-answer {
      max-height: 200px;
    }

    /* CTA 表单 */
    .cta-section {
      background-color: rgba(78, 110, 242, 0.03);
    }

    .form-wrap {
      max-width: 720px;
      margin: 0 auto;
      background: white;
      border-radius: var(--radius-card);
      padding: 32px 24px;
      box-shadow: var(--shadow-md);
    }

    .form-row {
      display: flex;
      flex-direction: column;
      gap: 16px;
    }

    @media (min-width: 768px) {
      .form-row {
        flex-direction: row;
      }
    }

    .form-input {
      flex: 1;
      padding: 14px 20px;
      border: 1px solid var(--border-light);
      border-radius: var(--radius-input);
      background: white;
      outline: none;
      transition: border 150ms, box-shadow 150ms;
    }

    .form-input:focus {
      border-color: var(--primary);
      box-shadow: 0 0 0 3px var(--primary-glow);
    }

    .form-submit {
      width: 100%;
      margin-top: 16px;
    }

    .trust-note {
      text-align: center;
      font-size: 12px;
      color: var(--text-secondary);
      margin-top: 16px;
    }

    /* Footer */
    .footer {
      background: #1F2329;
      color: #86909C;
      padding: 60px 0 30px;
    }

    .footer-grid {
      display: grid;
      grid-template-columns: repeat(2, 1fr);
      gap: 32px;
    }

    @media (min-width: 768px) {
      .footer-grid {
        grid-template-columns: 2fr 1fr 1fr 1fr;
      }
    }

    .footer-brand p {
      margin-top: 12px;
      font-size: 14px;
    }

    .footer-col h4 {
      color: white;
      font-weight: 600;
      margin-bottom: 16px;
      font-size: 16px;
    }

    .footer-col a {
      display: block;
      color: #86909C;
      margin-bottom: 10px;
      font-size: 14px;
    }

    .footer-col a:hover {
      color: white;
    }

    .footer-bottom {
      margin-top: 40px;
      padding-top: 20px;
      border-top: 1px solid #2E3238;
      font-size: 13px;
      text-align: center;
    }