/* roulang page: index */
:root {
      --primary: #E43D2A;
      --primary-dark: #C8321F;
      --primary-light: #FDE8E5;
      --secondary: #1A1A1A;
      --bg: #F7F5F2;
      --card-bg: #FFFFFF;
      --accent-green: #2C8C3F;
      --text-main: #1A1A1A;
      --text-muted: #5A5A5A;
      --border-light: #E0DDD8;
      --radius-card: 12px;
      --radius-btn: 8px;
      --radius-tag: 6px;
      --shadow-card: 0 2px 12px rgba(0,0,0,0.04);
      --shadow-hover: 0 8px 24px rgba(0,0,0,0.10);
      --transition: 0.25s ease;
      --font-title: 'PingFang SC', 'Microsoft YaHei', 'Helvetica Neue', sans-serif;
      --font-body: 'PingFang SC', 'Microsoft YaHei', 'Helvetica Neue', sans-serif;
      --font-number: 'DIN Alternate', 'SF Mono', 'Consolas', monospace;
    }

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

    body {
      font-family: var(--font-body);
      background-color: var(--bg);
      color: var(--text-main);
      line-height: 1.7;
      font-size: 16px;
      -webkit-font-smoothing: antialiased;
    }

    .container {
      max-width: 1280px;
      margin: 0 auto;
      padding: 0 16px;
    }

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

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

    button, .btn {
      cursor: pointer;
      font-family: var(--font-body);
      font-weight: 600;
      font-size: 16px;
      letter-spacing: 0.5px;
      border: none;
      outline: none;
      transition: var(--transition);
      display: inline-flex;
      align-items: center;
      justify-content: center;
    }

    h1, h2, h3, h4 {
      font-family: var(--font-title);
      font-weight: 700;
      color: var(--secondary);
    }

    h1 {
      font-size: 48px;
      line-height: 1.2;
    }

    h2 {
      font-size: 36px;
      line-height: 1.3;
      margin-bottom: 16px;
    }

    h3 {
      font-size: 20px;
      line-height: 1.4;
    }

    p {
      margin-bottom: 1.5em;
      color: var(--text-muted);
    }

    /* 导航 */
    .navbar {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 72px;
      background: rgba(255,255,255,0.96);
      backdrop-filter: blur(12px);
      -webkit-backdrop-filter: blur(12px);
      box-shadow: 0 1px 0 var(--border-light);
      z-index: 1000;
      display: flex;
      align-items: center;
    }

    .nav-container {
      display: flex;
      align-items: center;
      justify-content: space-between;
      width: 100%;
      max-width: 1280px;
      margin: 0 auto;
      padding: 0 16px;
    }

    .logo {
      font-family: var(--font-title);
      font-weight: 800;
      font-size: 24px;
      color: var(--primary);
      display: flex;
      align-items: center;
      gap: 6px;
    }

    .logo-icon {
      width: 28px;
      height: 28px;
      background: var(--primary);
      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-2-3-2 4-2-2-1 5h14l-2-9z"/><circle cx="6" cy="15" r="3" fill="currentColor"/><circle cx="18" cy="15" r="3"/></svg>') center/contain no-repeat;
      -webkit-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-2-3-2 4-2-2-1 5h14l-2-9z"/><circle cx="6" cy="15" r="3"/><circle cx="18" cy="15" r="3"/></svg>') center/contain no-repeat;
      background-color: var(--primary);
    }

    .nav-links {
      display: flex;
      gap: 32px;
      list-style: none;
      font-weight: 500;
      font-size: 16px;
      color: var(--text-muted);
    }

    .nav-links a {
      position: relative;
      padding: 8px 0;
      transition: color var(--transition);
    }

    .nav-links a:hover,
    .nav-links a.active {
      color: var(--primary);
    }

    .nav-links a.active::after {
      content: '';
      position: absolute;
      bottom: 0;
      left: 0;
      width: 100%;
      height: 2px;
      background: var(--primary);
      border-radius: 2px;
    }

    .nav-cta {
      background: var(--primary);
      color: white;
      height: 40px;
      padding: 0 24px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      font-size: 16px;
    }

    .nav-cta:hover {
      background: var(--primary-dark);
    }

    .hamburger {
      display: none;
      background: none;
      border: none;
      flex-direction: column;
      gap: 5px;
      width: 24px;
      padding: 4px;
    }

    .hamburger span {
      display: block;
      height: 2px;
      background: var(--secondary);
      border-radius: 2px;
      transition: var(--transition);
    }

    /* 移动端菜单 */
    .mobile-menu {
      position: fixed;
      top: 72px;
      left: 0;
      width: 100%;
      background: white;
      padding: 24px 16px;
      box-shadow: 0 8px 20px rgba(0,0,0,0.08);
      display: none;
      flex-direction: column;
      gap: 20px;
      z-index: 999;
    }

    .mobile-menu a {
      font-size: 20px;
      padding: 12px 0;
      border-bottom: 1px solid var(--border-light);
      color: var(--text-main);
    }

    .mobile-menu .mobile-cta {
      background: var(--primary);
      color: white;
      text-align: center;
      padding: 14px;
      border-radius: var(--radius-btn);
      margin-top: 8px;
    }

    /* Hero */
    .hero {
      padding: 120px 0 80px;
      display: flex;
      align-items: center;
      gap: 60px;
    }

    .hero-content {
      flex: 1;
    }

    .hero-image {
      flex: 1;
      border-radius: 16px;
      overflow: hidden;
      box-shadow: 0 20px 40px rgba(0,0,0,0.15);
    }

    .hero-image img {
      width: 100%;
      height: 100%;
      object-fit: cover;
      aspect-ratio: 4/3;
    }

    .hero h1 {
      margin-bottom: 20px;
    }

    .hero-subtitle {
      font-size: 18px;
      color: var(--text-muted);
      margin-bottom: 32px;
    }

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

    .btn-primary {
      background: var(--primary);
      color: white;
      height: 48px;
      padding: 0 32px;
      border-radius: var(--radius-btn);
      min-width: 140px;
    }

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

    .btn-outline {
      background: transparent;
      border: 1.5px solid var(--primary);
      color: var(--primary);
      height: 48px;
      padding: 0 32px;
      border-radius: var(--radius-btn);
      min-width: 140px;
    }

    .btn-outline:hover {
      background: var(--primary-light);
    }

    /* 板块通用 */
    section {
      padding: 100px 0;
    }

    .section-title {
      text-align: center;
      margin-bottom: 48px;
    }

    .section-title p {
      max-width: 600px;
      margin: 12px auto 0;
    }

    /* 核心优势 */
    .features-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 48px 32px;
    }

    .feature-item {
      display: flex;
      flex-direction: column;
    }

    .feature-icon {
      font-size: 32px;
      color: var(--primary);
      margin-bottom: 16px;
    }

    .feature-item h3 {
      margin-bottom: 8px;
    }

    /* 服务矩阵 */
    .services-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }

    .service-card {
      background: var(--card-bg);
      border-radius: var(--radius-card);
      overflow: hidden;
      box-shadow: var(--shadow-card);
      transition: var(--transition);
    }

    .service-card:hover {
      transform: translateY(-6px);
      box-shadow: var(--shadow-hover);
    }

    .service-img {
      height: 200px;
      overflow: hidden;
    }

    .service-img img {
      width: 100%;
      height: 100%;
      object-fit: cover;
      transition: transform 0.4s ease;
    }

    .service-card:hover .service-img img {
      transform: scale(1.03);
    }

    .service-body {
      padding: 24px;
    }

    .service-tags {
      display: flex;
      flex-wrap: wrap;
      gap: 8px;
      margin: 12px 0;
    }

    .tag {
      background: rgba(44,140,63,0.1);
      color: var(--accent-green);
      font-size: 12px;
      padding: 4px 10px;
      border-radius: var(--radius-tag);
      font-weight: 600;
    }

    /* 案例瀑布流 */
    .cases-masonry {
      display: grid;
      grid-template-columns: repeat(2, 1fr);
      gap: 24px;
    }

    .case-card {
      background: white;
      border-radius: var(--radius-card);
      overflow: hidden;
      box-shadow: var(--shadow-card);
    }

    .case-card img {
      width: 100%;
      height: auto;
      object-fit: cover;
    }

    .case-info {
      padding: 20px;
    }

    .case-number {
      font-family: var(--font-number);
      font-weight: 700;
      font-size: 28px;
      color: var(--accent-green);
    }

    /* 对比表 */
    .compare-table {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      background: white;
      border-radius: var(--radius-card);
      overflow: hidden;
      box-shadow: var(--shadow-card);
    }

    .compare-col {
      padding: 24px 16px;
      text-align: center;
    }

    .compare-col.header {
      font-weight: 700;
      font-size: 18px;
      background: #f0f0f0;
    }

    .compare-col.featured {
      background: var(--primary);
      color: white;
    }

    .compare-row {
      display: contents;
    }

    /* FAQ */
    .faq-list {
      max-width: 800px;
      margin: 0 auto;
    }

    .faq-item {
      border-bottom: 1px solid var(--border-light);
    }

    .faq-question {
      width: 100%;
      background: none;
      text-align: left;
      font-size: 18px;
      font-weight: 500;
      padding: 20px 0;
      display: flex;
      justify-content: space-between;
      align-items: center;
      color: var(--secondary);
    }

    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.35s ease;
      line-height: 1.8;
      color: var(--text-muted);
    }

    .faq-answer.open {
      max-height: 200px;
      padding-bottom: 20px;
    }

    /* CTA横幅 */
    .cta-band {
      background: var(--secondary);
      color: white;
      text-align: center;
      padding: 80px 0;
    }

    .cta-band h2 {
      color: white;
      margin-bottom: 16px;
    }

    .cta-band .btn-primary {
      margin-top: 24px;
      height: 56px;
      padding: 0 40px;
      border-radius: 12px;
      font-size: 18px;
    }

    /* 页脚 */
    .footer {
      background: white;
      padding: 60px 0 30px;
      border-top: 1px solid var(--border-light);
    }

    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 40px;
    }

    .footer-links {
      list-style: none;
      font-size: 15px;
    }

    .footer-links li {
      margin-bottom: 12px;
    }

    .copyright {
      text-align: center;
      margin-top: 40px;
      padding-top: 20px;
      border-top: 1px solid var(--border-light);
      font-size: 14px;
      color: var(--text-muted);
    }

    @media (max-width: 1024px) {
      .hero {
        flex-direction: column;
        padding-top: 100px;
      }
      .features-grid {
        grid-template-columns: repeat(2, 1fr);
      }
      .services-grid {
        grid-template-columns: repeat(2, 1fr);
      }
    }

    @media (max-width: 768px) {
      h1 { font-size: 36px; }
      h2 { font-size: 28px; }
      .nav-links, .nav-cta {
        display: none;
      }
      .hamburger {
        display: flex;
      }
      .features-grid {
        grid-template-columns: 1fr;
      }
      .services-grid {
        grid-template-columns: 1fr;
      }
      .cases-masonry {
        grid-template-columns: 1fr;
      }
      .compare-table {
        grid-template-columns: repeat(4, 1fr);
        overflow-x: auto;
        display: flex;
        width: 100%;
      }
      .compare-col {
        min-width: 140px;
      }
      .footer-grid {
        grid-template-columns: 1fr;
      }
      section {
        padding: 60px 0;
      }
    }