/* roulang page: index */
/* 设计变量与基础重置 */
    :root {
      --deep-anchor: #0B1E33;
      --vibrant-orange: #F15A24;
      --bg-light: #F7F8FA;
      --card-white: #FFFFFF;
      --text-primary: #2E3A46;
      --text-secondary: #6B7280;
      --border-light: #E5E7EB;
      --radius-card: 12px;
      --radius-btn: 8px;
      --shadow-card: 0 4px 20px rgba(0,0,0,0.04), 0 1px 3px rgba(0,0,0,0.03);
      --shadow-hover: 0 12px 32px rgba(0,0,0,0.08);
      --transition: all 0.25s ease;
      --container-max: 1280px;
      --section-gap: 100px;
      --card-padding: 28px;
    }
    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }
    body {
      font-family: system-ui, -apple-system, "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
      background-color: var(--bg-light);
      color: var(--text-primary);
      line-height: 1.7;
      font-size: 16px;
      -webkit-font-smoothing: antialiased;
    }
    img {
      display: block;
      max-width: 100%;
      height: auto;
    }
    a {
      text-decoration: none;
      color: inherit;
    }
    button, input, textarea {
      font-family: inherit;
    }
    .container {
      max-width: var(--container-max);
      margin: 0 auto;
      padding: 0 24px;
    }
    /* 导航栏 */
    .site-header {
      position: sticky;
      top: 0;
      z-index: 50;
      background: rgba(255,255,255,0.96);
      backdrop-filter: blur(8px);
      border-bottom: 1px solid var(--border-light);
      height: 64px;
      display: flex;
      align-items: center;
    }
    .header-inner {
      display: flex;
      justify-content: space-between;
      align-items: center;
      width: 100%;
    }
    .logo {
      display: flex;
      align-items: center;
      gap: 10px;
      font-weight: 700;
      font-size: 22px;
      color: var(--deep-anchor);
      letter-spacing: -0.3px;
    }
    .logo-icon {
      width: 34px;
      height: 34px;
      background: var(--vibrant-orange);
      mask: url('data:image/svg+xml;utf8,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24"><path d="M13.5 2L12 7l-3.5 2L7 6l-3 4.5h3L9 15l2.5-2.5L14 18h2l-3.5-7.5L16 7l-2.5 3V2z"/></svg>') center/contain no-repeat;
      background-color: var(--vibrant-orange);
    }
    .nav-links {
      display: flex;
      gap: 32px;
      align-items: center;
    }
    .nav-links a {
      font-size: 15px;
      font-weight: 500;
      color: var(--text-primary);
      position: relative;
      padding: 8px 0;
      transition: color 0.2s;
    }
    .nav-links a:hover,
    .nav-links a.active {
      color: var(--vibrant-orange);
    }
    .nav-links a.active::after {
      content: '';
      position: absolute;
      bottom: 0;
      left: 0;
      width: 100%;
      height: 2px;
      background: var(--vibrant-orange);
    }
    .hamburger {
      display: none;
      flex-direction: column;
      gap: 5px;
      background: none;
      border: none;
      cursor: pointer;
      padding: 8px;
    }
    .hamburger span {
      width: 24px;
      height: 2px;
      background: var(--deep-anchor);
      transition: 0.2s;
    }
    /* 移动端导航 */
    @media (max-width: 768px) {
      .nav-links {
        position: fixed;
        top: 64px;
        left: 0;
        width: 100%;
        background: white;
        flex-direction: column;
        padding: 32px 24px;
        gap: 24px;
        box-shadow: 0 24px 40px rgba(0,0,0,0.12);
        transform: translateY(-120%);
        opacity: 0;
        transition: 0.3s ease;
        pointer-events: none;
      }
      .nav-links.open {
        transform: translateY(0);
        opacity: 1;
        pointer-events: auto;
      }
      .hamburger {
        display: flex;
      }
    }
    /* 板块间距 */
    section {
      padding: var(--section-gap) 0;
    }
    @media (max-width: 768px) {
      section {
        padding: 64px 0;
      }
    }
    /* 首屏 Hero 分屏布局 */
    .hero-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      min-height: 85vh;
      align-items: center;
      gap: 60px;
    }
    .hero-text {
      display: flex;
      flex-direction: column;
      gap: 24px;
    }
    .hero-text h1 {
      font-size: clamp(36px, 5vw, 48px);
      font-weight: 700;
      color: var(--deep-anchor);
      line-height: 1.2;
      letter-spacing: -0.5px;
    }
    .hero-sub {
      font-size: 18px;
      color: var(--text-primary);
    }
    .hero-desc {
      color: var(--text-secondary);
      max-width: 480px;
    }
    .btn-primary {
      background: var(--vibrant-orange);
      color: white;
      border: none;
      padding: 14px 34px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      font-size: 16px;
      cursor: pointer;
      display: inline-block;
      transition: var(--transition);
      box-shadow: 0 4px 10px rgba(241,90,36,0.2);
      align-self: flex-start;
    }
    .btn-primary:hover {
      background: #D94A1A;
      transform: scale(1.03);
      box-shadow: 0 8px 18px rgba(241,90,36,0.3);
    }
    .hero-visual {
      position: relative;
      border-radius: 24px;
      overflow: hidden;
      height: 520px;
      background: url('/assets/images/backpic/back-1.webp') center/cover no-repeat;
      box-shadow: 0 25px 50px -12px rgba(0,0,0,0.25);
    }
    .hero-visual::after {
      content: '';
      position: absolute;
      inset: 0;
      background: rgba(11,30,51,0.28);
    }
    @media (max-width: 1024px) {
      .hero-grid {
        grid-template-columns: 1fr;
        text-align: center;
        gap: 48px;
      }
      .hero-text {
        align-items: center;
      }
      .hero-visual {
        height: 380px;
        order: -1;
      }
    }
    /* 标题通用 */
    h2 {
      font-size: 32px;
      font-weight: 600;
      color: var(--deep-anchor);
      margin-bottom: 16px;
      letter-spacing: -0.3px;
    }
    .section-intro {
      color: var(--text-secondary);
      margin-bottom: 48px;
      font-size: 17px;
    }
    /* 亮点网格 */
    .highlights-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }
    .highlight-card {
      background: var(--card-white);
      padding: var(--card-padding);
      border-radius: var(--radius-card);
      box-shadow: var(--shadow-card);
      transition: var(--transition);
      display: flex;
      flex-direction: column;
      gap: 16px;
    }
    .highlight-card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-hover);
    }
    .highlight-icon {
      width: 44px;
      height: 44px;
      color: var(--vibrant-orange);
    }
    .highlight-card h3 {
      font-size: 22px;
      font-weight: 600;
      color: var(--deep-anchor);
    }
    @media (max-width: 768px) {
      .highlights-grid {
        grid-template-columns: 1fr;
      }
    }
    /* 案例瀑布流 */
    .cases-masonry {
      display: grid;
      grid-template-columns: repeat(2, 1fr);
      gap: 24px;
      align-items: start;
    }
    .case-card {
      background: var(--card-white);
      border-radius: var(--radius-card);
      overflow: hidden;
      box-shadow: var(--shadow-card);
      transition: var(--transition);
    }
    .case-card:hover {
      transform: translateY(-6px);
      box-shadow: var(--shadow-hover);
    }
    .case-img {
      height: 260px;
      background-size: cover;
      background-position: center;
      position: relative;
    }
    .case-img::after {
      content: '';
      position: absolute;
      bottom: 0;
      left: 0;
      width: 100%;
      height: 70%;
      background: linear-gradient(to top, rgba(11,30,51,0.7), transparent);
    }
    .case-content {
      padding: 20px 24px 28px;
    }
    .case-content h3 {
      font-size: 20px;
      font-weight: 600;
      margin-bottom: 8px;
      color: var(--deep-anchor);
    }
    @media (max-width: 768px) {
      .cases-masonry {
        grid-template-columns: 1fr;
      }
    }
    /* 方案对比 */
    .compare-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 32px;
    }
    .compare-card {
      background: var(--card-white);
      border-radius: var(--radius-card);
      padding: 32px;
      box-shadow: var(--shadow-card);
    }
    .compare-card.old {
      border-left: 6px solid #9CA3AF;
    }
    .compare-card.new {
      border-left: 6px solid var(--vibrant-orange);
      background: #FFF9F5;
    }
    .compare-list {
      list-style: none;
      margin-top: 24px;
    }
    .compare-list li {
      display: flex;
      align-items: center;
      gap: 12px;
      margin-bottom: 16px;
      font-size: 16px;
    }
    .icon-cross {
      color: #9CA3AF;
      font-weight: bold;
    }
    .icon-check {
      color: var(--vibrant-orange);
      font-weight: bold;
    }
    @media (max-width: 768px) {
      .compare-grid {
        grid-template-columns: 1fr;
      }
    }
    /* FAQ */
    .faq-list {
      max-width: 800px;
      margin: 0 auto;
    }
    .faq-item {
      border-bottom: 1px solid var(--border-light);
      padding: 24px 0;
      cursor: pointer;
    }
    .faq-question {
      display: flex;
      justify-content: space-between;
      align-items: center;
      font-weight: 600;
      font-size: 18px;
      color: var(--deep-anchor);
      position: relative;
      padding-left: 16px;
    }
    .faq-question::before {
      content: '';
      position: absolute;
      left: 0;
      top: 4px;
      bottom: 4px;
      width: 3px;
      background: var(--vibrant-orange);
      transition: height 0.2s;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease;
      color: var(--text-primary);
      padding-left: 16px;
    }
    .faq-item.open .faq-answer {
      max-height: 150px;
      margin-top: 16px;
    }
    .faq-toggle {
      width: 28px;
      height: 28px;
      border-radius: 50%;
      border: 1.5px solid var(--vibrant-orange);
      background: transparent;
      font-weight: bold;
      color: var(--vibrant-orange);
      display: flex;
      align-items: center;
      justify-content: center;
    }
    /* 联系表单 */
    .contact-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 48px;
    }
    .contact-form input,
    .contact-form textarea {
      width: 100%;
      padding: 14px;
      border: 1px solid var(--border-light);
      border-radius: 6px;
      background: #F9FAFB;
      margin-bottom: 20px;
      transition: 0.2s;
    }
    .contact-form input:focus,
    .contact-form textarea:focus {
      border-color: var(--vibrant-orange);
      outline: none;
      background: white;
    }
    .contact-info p {
      margin-bottom: 16px;
      display: flex;
      align-items: center;
      gap: 12px;
    }
    @media (max-width: 768px) {
      .contact-grid {
        grid-template-columns: 1fr;
      }
    }
    /* 页脚 */
    .site-footer {
      background: var(--deep-anchor);
      color: rgba(255,255,255,0.85);
      padding: 64px 0 32px;
      margin-top: 80px;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr;
      gap: 40px;
    }
    .footer-logo {
      font-size: 24px;
      font-weight: 700;
      color: white;
    }
    .footer-links a {
      display: block;
      color: rgba(255,255,255,0.7);
      margin-bottom: 12px;
      transition: 0.2s;
    }
    .footer-links a:hover {
      color: var(--vibrant-orange);
    }
    .copyright {
      border-top: 1px solid rgba(255,255,255,0.15);
      margin-top: 40px;
      padding-top: 24px;
      text-align: center;
      font-size: 14px;
      color: rgba(255,255,255,0.6);
    }
    @media (max-width: 768px) {
      .footer-grid {
        grid-template-columns: 1fr;
      }
    }