/* roulang page: index */
:root {
      --primary: #4E6EF2;
      --primary-light: #EEF1FE;
      --primary-dark: #3A4FC2;
      --secondary: #00B578;
      --warning: #FF9F0A;
      --danger: #FA5151;
      --bg: #F5F6FA;
      --card-bg: #FFFFFF;
      --text-main: #1F2329;
      --text-secondary: #86909C;
      --border-light: #E5E8EF;
      --footer-bg: #1F2329;
      --radius-md: 12px;
      --radius-sm: 8px;
      --radius-xl: 20px;
      --shadow-sm: 0 2px 12px rgba(0,0,0,0.04);
      --shadow-hover: 0 6px 24px rgba(0,0,0,0.08);
      --font-stack: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
      --transition: 0.2s ease-out;
    }

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

    body {
      font-family: var(--font-stack);
      background-color: var(--bg);
      color: var(--text-main);
      line-height: 1.5;
      -webkit-font-smoothing: antialiased;
      text-rendering: optimizeLegibility;
    }

    .container {
      max-width: 1200px;
      margin: 0 auto;
      padding: 0 24px;
    }

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

    a {
      text-decoration: none;
      color: inherit;
    }

    button, .btn {
      cursor: pointer;
      border: none;
      background: none;
      font-family: inherit;
      font-size: 16px;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      gap: 8px;
      transition: var(--transition);
      border-radius: var(--radius-sm);
      padding: 12px 28px;
      font-weight: 500;
      line-height: 1.2;
    }

    .btn-primary {
      background-color: var(--primary);
      color: white;
      box-shadow: 0 2px 8px rgba(78,110,242,0.25);
    }
    .btn-primary:hover {
      background-color: #5A7AF5;
      box-shadow: 0 4px 14px rgba(78,110,242,0.35);
      transform: translateY(-1px);
    }
    .btn-primary:active {
      background-color: var(--primary-dark);
      box-shadow: inset 0 2px 6px rgba(0,0,0,0.1);
      transform: translateY(0);
    }

    .btn-outline {
      background: transparent;
      border: 1px solid var(--primary);
      color: var(--primary);
    }
    .btn-outline:hover {
      background: var(--primary-light);
      border-color: var(--primary);
      color: var(--primary);
    }

    .btn-white {
      background: white;
      color: var(--primary);
      font-weight: 600;
    }
    .btn-white:hover {
      background: #f0f2ff;
    }

    .btn-outline-white {
      background: transparent;
      border: 1px solid rgba(255,255,255,0.5);
      color: white;
    }
    .btn-outline-white:hover {
      background: rgba(255,255,255,0.15);
      border-color: white;
    }

    /* 导航 */
    .header {
      position: sticky;
      top: 0;
      z-index: 50;
      background: rgba(255,255,255,0.92);
      backdrop-filter: blur(18px);
      -webkit-backdrop-filter: blur(18px);
      height: 64px;
      display: flex;
      align-items: center;
      border-bottom: 1px solid rgba(0,0,0,0.03);
      box-shadow: 0 1px 8px rgba(0,0,0,0.02);
    }
    .header .container {
      display: flex;
      align-items: center;
      justify-content: space-between;
      width: 100%;
    }
    .logo {
      font-size: 22px;
      font-weight: 700;
      color: var(--primary);
      letter-spacing: -0.3px;
      display: flex;
      align-items: center;
      gap: 6px;
    }
    .logo span {
      background: var(--primary);
      color: white;
      border-radius: 8px;
      padding: 0 8px;
      font-size: 20px;
      margin-right: 2px;
    }
    .nav-links {
      display: flex;
      gap: 32px;
      align-items: center;
    }
    .nav-links a {
      font-size: 14px;
      font-weight: 500;
      color: var(--text-main);
      position: relative;
      padding: 6px 0;
      transition: color 0.2s;
    }
    .nav-links a::after {
      content: '';
      position: absolute;
      bottom: 0;
      left: 0;
      width: 0;
      height: 2px;
      background: var(--primary);
      transition: width 0.2s ease;
    }
    .nav-links a:hover {
      color: var(--primary);
    }
    .nav-links a:hover::after {
      width: 100%;
    }
    .mobile-toggle {
      display: none;
      background: none;
      border: none;
      font-size: 26px;
      color: var(--text-main);
    }

    /* Hero */
    .hero {
      padding: 60px 0 80px;
      background: linear-gradient(135deg, #ffffff 0%, #f2f4ff 100%);
    }
    .hero .container {
      display: flex;
      align-items: center;
      gap: 50px;
    }
    .hero-left {
      flex: 1;
    }
    .hero-left h1 {
      font-size: 42px;
      font-weight: 700;
      line-height: 1.2;
      color: var(--text-main);
      margin-bottom: 18px;
    }
    .hero-left .sub {
      font-size: 17px;
      color: var(--text-secondary);
      margin-bottom: 32px;
      max-width: 460px;
    }
    .hero-buttons {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
    }
    .hero-right {
      flex: 1;
      display: flex;
      justify-content: center;
    }
    .hero-right img {
      max-width: 100%;
      height: auto;
      border-radius: 24px;
      box-shadow: 0 20px 40px rgba(0,0,0,0.08);
    }
    .highlight {
      color: var(--primary);
    }

    /* 板块通用 */
    section {
      padding: 80px 0;
    }
    .section-title {
      font-size: 28px;
      font-weight: 700;
      margin-bottom: 16px;
      color: var(--text-main);
    }
    .section-sub {
      font-size: 16px;
      color: var(--text-secondary);
      margin-bottom: 48px;
    }

    /* 亮点网格 */
    .features-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }
    .feature-card {
      background: var(--card-bg);
      border-radius: var(--radius-md);
      padding: 28px 24px;
      box-shadow: var(--shadow-sm);
      transition: var(--transition);
    }
    .feature-card:hover {
      box-shadow: var(--shadow-hover);
      transform: translateY(-4px);
    }
    .icon-accent {
      width: 48px;
      height: 48px;
      background: var(--primary-light);
      border-radius: 12px;
      display: flex;
      align-items: center;
      justify-content: center;
      color: var(--primary);
      font-size: 24px;
      margin-bottom: 20px;
    }
    .feature-card h3 {
      font-size: 20px;
      font-weight: 600;
      margin-bottom: 8px;
    }
    .feature-card p {
      color: var(--text-secondary);
      font-size: 15px;
    }

    /* 案例瀑布 */
    .cases-masonry {
      columns: 3;
      column-gap: 24px;
      break-inside: avoid;
    }
    .case-card {
      background: var(--card-bg);
      border-radius: var(--radius-md);
      overflow: hidden;
      box-shadow: var(--shadow-sm);
      margin-bottom: 24px;
      transition: var(--transition);
      break-inside: avoid;
    }
    .case-card:hover {
      box-shadow: var(--shadow-hover);
      transform: translateY(-3px);
    }
    .case-card img {
      width: 100%;
      object-fit: cover;
      aspect-ratio: 16/10;
    }
    .case-content {
      padding: 18px;
    }
    .case-tag {
      display: inline-block;
      background: var(--primary-light);
      color: var(--primary);
      font-size: 12px;
      padding: 2px 12px;
      border-radius: 20px;
      margin-bottom: 8px;
    }
    .case-title {
      font-weight: 600;
      font-size: 17px;
      margin-bottom: 4px;
    }

    /* 方案对比 */
    .compare-table {
      display: flex;
      gap: 20px;
      justify-content: center;
      flex-wrap: wrap;
    }
    .plan-card {
      background: white;
      border-radius: var(--radius-md);
      padding: 32px 24px;
      flex: 1;
      min-width: 240px;
      box-shadow: var(--shadow-sm);
      border: 1px solid transparent;
    }
    .plan-highlight {
      border-color: var(--primary);
      background: #f8faff;
    }
    .plan-name {
      font-weight: 700;
      font-size: 22px;
      margin-bottom: 12px;
    }
    .plan-feature {
      color: var(--text-secondary);
      margin: 12px 0;
      display: flex;
      align-items: center;
      gap: 8px;
    }

    /* FAQ */
    .faq-list {
      max-width: 720px;
      margin: 0 auto;
    }
    .faq-item {
      border-bottom: 1px solid var(--border-light);
      padding: 20px 0;
    }
    .faq-question {
      font-weight: 600;
      font-size: 18px;
      cursor: pointer;
      display: flex;
      justify-content: space-between;
      align-items: center;
      color: var(--text-main);
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease, padding 0.3s;
      color: var(--text-secondary);
      font-size: 16px;
    }
    .faq-item.active .faq-answer {
      max-height: 200px;
      padding-top: 12px;
    }

    /* CTA */
    .cta-banner {
      background: var(--primary);
      padding: 60px 24px;
      text-align: center;
      border-radius: 24px;
      color: white;
    }
    .cta-banner h2 {
      font-size: 32px;
      font-weight: 700;
      margin-bottom: 20px;
    }
    .cta-buttons {
      display: flex;
      gap: 18px;
      justify-content: center;
      flex-wrap: wrap;
    }

    /* 页脚 */
    .footer {
      background: var(--footer-bg);
      color: #ddd;
      padding: 60px 0 20px;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1.5fr;
      gap: 30px;
    }
    .footer h4 {
      color: white;
      margin-bottom: 18px;
      font-weight: 600;
    }
    .footer a {
      color: #aaa;
      font-size: 14px;
      display: block;
      margin: 6px 0;
    }
    .copyright {
      border-top: 1px solid #333;
      margin-top: 40px;
      padding-top: 20px;
      font-size: 13px;
      color: #888;
    }

    @media (max-width: 1024px) {
      .features-grid { grid-template-columns: repeat(2,1fr); }
      .cases-masonry { columns: 2; }
    }
    @media (max-width: 768px) {
      .nav-links { display: none; }
      .mobile-toggle { display: block; }
      .hero .container { flex-direction: column; text-align: center; }
      .hero-left h1 { font-size: 34px; }
      .features-grid { grid-template-columns: 1fr; }
      .cases-masonry { columns: 1; }
      .footer-grid { grid-template-columns: 1fr 1fr; }
      .compare-table { flex-direction: column; }
    }
    @media (max-width: 520px) {
      .footer-grid { grid-template-columns: 1fr; }
      .hero-buttons { flex-direction: column; align-items: center; }
    }