/* roulang page: index */
:root {
      --primary: #4E6EF2;
      --primary-hover: #3A5CE4;
      --primary-light: #EEF1FF;
      --secondary: #FF7A00;
      --success: #00B578;
      --danger: #FA5151;
      --bg: #F5F6FA;
      --white: #FFFFFF;
      --text: #1F2329;
      --text-secondary: #86909C;
      --border-light: #E5E8EF;
      --shadow-card: 0 2px 12px rgba(0,0,0,0.06);
      --shadow-hover: 0 6px 20px rgba(0,0,0,0.10);
      --shadow-nav: 0 1px 4px rgba(0,0,0,0.04);
      --radius-card: 12px;
      --radius-btn: 8px;
      --radius-input: 20px;
      --max-width: 1200px;
      --transition: 200ms ease-out;
      --font-stack: -apple-system, BlinkMacSystemFont, "PingFang SC", "Microsoft YaHei", "Helvetica Neue", sans-serif;
    }

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

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

    .container {
      max-width: var(--max-width);
      margin: 0 auto;
      padding: 0 32px;
    }

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

    a {
      text-decoration: none;
      color: inherit;
      transition: color var(--transition);
    }

    button, .btn {
      cursor: pointer;
      font-family: inherit;
      border: none;
      background: none;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      gap: 8px;
      font-weight: 600;
      transition: all var(--transition);
    }

    /* 导航 */
    #nav {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      background: rgba(255,255,255,0.98);
      backdrop-filter: blur(12px);
      box-shadow: var(--shadow-nav);
      border-bottom: 1px solid var(--border-light);
      z-index: 100;
      height: 64px;
      display: flex;
      align-items: center;
    }

    .nav-container {
      display: flex;
      align-items: center;
      justify-content: space-between;
      width: 100%;
    }

    .logo {
      font-size: 20px;
      font-weight: 700;
      color: var(--primary);
      letter-spacing: 1px;
      display: flex;
      align-items: center;
      gap: 6px;
    }
    .logo i {
      font-size: 24px;
    }

    .nav-menu {
      display: flex;
      gap: 32px;
      list-style: none;
    }

    .nav-menu a {
      font-size: 14px;
      font-weight: 500;
      color: var(--text);
      padding: 8px 0;
      position: relative;
    }
    .nav-menu a:hover,
    .nav-menu a.active {
      color: var(--primary);
    }
    .nav-menu a::after {
      content: '';
      position: absolute;
      bottom: 0;
      left: 0;
      width: 0;
      height: 2px;
      background: var(--primary);
      transition: width var(--transition);
    }
    .nav-menu a:hover::after,
    .nav-menu a.active::after {
      width: 100%;
    }

    .btn-primary {
      background: var(--primary);
      color: white;
      padding: 10px 24px;
      border-radius: var(--radius-btn);
      font-size: 14px;
      font-weight: 600;
      box-shadow: 0 2px 6px rgba(78,110,242,0.2);
    }
    .btn-primary:hover {
      background: var(--primary-hover);
    }

    .btn-outline {
      background: transparent;
      color: var(--primary);
      border: 1.5px solid var(--primary);
      padding: 10px 24px;
      border-radius: var(--radius-btn);
      font-size: 14px;
      font-weight: 600;
    }
    .btn-outline:hover {
      background: var(--primary-light);
    }

    .hamburger {
      display: none;
      font-size: 24px;
      color: var(--text);
      background: none;
      border: none;
    }

    /* 移动端抽屉 */
    .mobile-drawer {
      display: none;
      position: fixed;
      top: 64px;
      left: 0;
      width: 100%;
      height: calc(100vh - 64px);
      background: rgba(255,255,255,0.98);
      backdrop-filter: blur(16px);
      flex-direction: column;
      padding: 24px 32px;
      gap: 12px;
      z-index: 99;
      transform: translateX(100%);
      transition: transform 0.3s ease;
    }
    .mobile-drawer.open {
      transform: translateX(0);
      display: flex;
    }
    .mobile-drawer a {
      font-size: 18px;
      font-weight: 500;
      padding: 12px 0;
      border-bottom: 1px solid var(--border-light);
    }

    /* 区块间距 */
    section {
      padding: 80px 0;
    }

    /* 首屏 Hero */
    #hero {
      padding-top: 120px;
      display: flex;
      align-items: center;
      gap: 60px;
    }
    .hero-left {
      flex: 1 1 45%;
    }
    .hero-right {
      flex: 1 1 55%;
      border-radius: 16px;
      overflow: hidden;
      box-shadow: var(--shadow-card);
    }
    .hero-right img {
      width: 100%;
      height: auto;
      object-fit: cover;
      aspect-ratio: 16/9;
      background: #d0d5e0;
    }
    .hero-left h1 {
      font-size: 36px;
      font-weight: 700;
      line-height: 1.3;
      margin-bottom: 20px;
      color: var(--text);
    }
    .hero-left h2 {
      font-size: 18px;
      font-weight: 400;
      color: var(--text-secondary);
      margin-bottom: 32px;
      line-height: 1.6;
    }
    .hero-cta {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
    }

    /* 亮点网格 */
    .grid-2x2 {
      display: grid;
      grid-template-columns: repeat(2, 1fr);
      gap: 24px;
    }
    .advantage-card {
      background: var(--white);
      border-radius: var(--radius-card);
      padding: 28px 24px;
      box-shadow: var(--shadow-card);
      display: flex;
      flex-direction: column;
      align-items: flex-start;
      transition: all 0.25s cubic-bezier(0.2,0.8,0.4,1);
    }
    .advantage-card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-hover);
    }
    .icon-circle {
      width: 48px;
      height: 48px;
      background: var(--primary-light);
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      color: var(--primary);
      font-size: 24px;
      margin-bottom: 16px;
    }
    .advantage-card h3 {
      font-size: 18px;
      font-weight: 600;
      margin-bottom: 8px;
    }
    .advantage-card p {
      font-size: 14px;
      color: var(--text-secondary);
      line-height: 1.5;
    }

    /* 案例瀑布流 */
    .masonry {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }
    .case-card {
      background: var(--white);
      border-radius: var(--radius-card);
      overflow: hidden;
      box-shadow: var(--shadow-card);
      transition: all 0.25s cubic-bezier(0.2,0.8,0.4,1);
      break-inside: avoid;
    }
    .case-card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-hover);
    }
    .case-img {
      width: 100%;
      aspect-ratio: 16/9;
      object-fit: cover;
      background: #d5d9e6;
      transition: transform 0.25s ease;
    }
    .case-card:hover .case-img {
      transform: scale(1.03);
    }
    .case-info {
      padding: 16px;
    }
    .case-info h4 {
      font-size: 16px;
      font-weight: 600;
      margin-bottom: 8px;
    }
    .tag {
      display: inline-block;
      background: var(--secondary);
      color: white;
      font-size: 12px;
      padding: 2px 10px;
      border-radius: 20px;
      font-weight: 500;
    }

    /* 方案对比 */
    .compare-row {
      display: flex;
      gap: 24px;
      align-items: stretch;
    }
    .plan-card {
      background: var(--white);
      border-radius: var(--radius-card);
      padding: 32px 24px;
      box-shadow: var(--shadow-card);
      flex: 1;
      display: flex;
      flex-direction: column;
      border: 2px solid transparent;
      transition: all 0.2s;
    }
    .plan-card.highlight {
      border-color: var(--primary);
      position: relative;
    }
    .badge {
      background: var(--secondary);
      color: white;
      font-size: 12px;
      padding: 4px 12px;
      border-radius: 20px;
      position: absolute;
      top: -12px;
      right: 20px;
      font-weight: 600;
    }
    .plan-name {
      font-size: 20px;
      font-weight: 700;
      margin-bottom: 8px;
    }
    .plan-price {
      font-size: 24px;
      font-weight: 700;
      color: var(--primary);
      margin-bottom: 20px;
    }
    .feature-list {
      list-style: none;
      margin-bottom: 24px;
    }
    .feature-list li {
      font-size: 14px;
      margin-bottom: 12px;
      display: flex;
      align-items: center;
      gap: 8px;
    }
    .fa-check-circle { color: var(--success); }
    .fa-times-circle { color: var(--danger); }

    /* FAQ */
    .faq-list {
      max-width: 800px;
      margin: 0 auto;
    }
    .faq-item {
      background: var(--white);
      border-radius: var(--radius-btn);
      margin-bottom: 12px;
      box-shadow: 0 1px 4px rgba(0,0,0,0.02);
    }
    .faq-question {
      padding: 16px 20px;
      font-weight: 600;
      font-size: 16px;
      display: flex;
      justify-content: space-between;
      align-items: center;
      cursor: pointer;
      background: none;
      width: 100%;
      border: none;
      text-align: left;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease;
      padding: 0 20px;
      font-size: 14px;
      color: var(--text-secondary);
      line-height: 1.6;
    }
    .faq-item.active .faq-answer {
      max-height: 200px;
      padding-bottom: 16px;
    }
    .faq-item.active .fa-chevron-down {
      transform: rotate(180deg);
    }

    /* CTA banner */
    .cta-banner {
      background: var(--primary);
      text-align: center;
      padding: 70px 0;
      color: white;
    }
    .cta-banner h2 {
      font-size: 28px;
      font-weight: 600;
      margin-bottom: 12px;
    }
    .cta-banner p {
      font-size: 16px;
      opacity: 0.9;
      margin-bottom: 28px;
    }
    .btn-white {
      background: white;
      color: var(--primary);
      padding: 12px 32px;
      border-radius: var(--radius-btn);
      font-weight: 700;
    }

    /* 页脚 */
    footer {
      background: var(--white);
      padding: 60px 0 20px;
      border-top: 1px solid var(--border-light);
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1.5fr 1fr;
      gap: 30px;
    }
    .footer-brand p {
      font-size: 14px;
      color: var(--text-secondary);
      margin-top: 10px;
    }
    .footer-links h4, .footer-contact h4 {
      margin-bottom: 16px;
      font-size: 16px;
    }
    .footer-links a, .footer-contact li {
      font-size: 14px;
      color: var(--text-secondary);
      display: block;
      margin-bottom: 8px;
    }
    .footer-contact i {
      width: 20px;
      color: var(--primary);
      margin-right: 8px;
    }
    .social-icons i {
      font-size: 20px;
      margin-right: 12px;
      color: var(--primary);
    }
    .copyright {
      margin-top: 40px;
      padding-top: 16px;
      border-top: 1px solid var(--border-light);
      font-size: 12px;
      color: var(--text-secondary);
      text-align: center;
    }

    /* 响应式 */
    @media (max-width: 1024px) {
      .container { padding: 0 24px; }
      .masonry { grid-template-columns: repeat(2,1fr); }
      .compare-row { flex-direction: column; }
    }
    @media (max-width: 767px) {
      .container { padding: 0 16px; }
      .nav-menu, .nav-container .btn-primary { display: none; }
      .hamburger { display: block; }
      #hero { flex-direction: column; padding-top: 100px; }
      .hero-left h1 { font-size: 28px; }
      .grid-2x2 { grid-template-columns: 1fr; }
      .masonry { grid-template-columns: 1fr; }
      .compare-row { overflow-x: auto; scroll-snap-type: x mandatory; display: flex; flex-direction: row; }
      .plan-card { min-width: 280px; scroll-snap-align: start; }
      .footer-grid { grid-template-columns: 1fr; }
    }