/* roulang page: index */
:root {
      --primary: #E53E3E;
      --primary-dark: #C53030;
      --secondary: #1A202C;
      --accent: #F6AD55;
      --bg: #F7F8FA;
      --card-bg: #FFFFFF;
      --text-primary: #1A202C;
      --text-body: #4A5568;
      --text-muted: #A0AEC0;
      --text-light: #E2E8F0;
      --white: #FFFFFF;
      --border-light: #E2E8F0;
      --shadow-sm: 0 2px 12px rgba(0,0,0,0.04);
      --shadow-md: 0 8px 24px rgba(0,0,0,0.08);
      --shadow-focus: 0 0 0 3px rgba(229,62,62,0.2);
      --radius-sm: 8px;
      --radius-md: 12px;
      --radius-lg: 16px;
      --transition: 0.25s ease;
      --max-width: 1200px;
    }

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

    body {
      font-family: "PingFang SC", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
      background-color: var(--bg);
      color: var(--text-body);
      line-height: 1.7;
      -webkit-font-smoothing: antialiased;
    }

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

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

    button, input, textarea {
      font-family: inherit;
      outline: none;
    }

    .container {
      max-width: var(--max-width);
      margin: 0 auto;
      padding: 0 24px;
    }

    /* 导航 */
    .header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 72px;
      background: rgba(255,255,255,0.95);
      backdrop-filter: blur(8px);
      border-bottom: 1px solid var(--border-light);
      z-index: 100;
      display: flex;
      align-items: center;
    }

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

    .logo {
      font-size: 24px;
      font-weight: 700;
      color: var(--secondary);
      letter-spacing: 1px;
      white-space: nowrap;
    }

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

    .nav-links {
      display: flex;
      align-items: center;
      gap: 32px;
    }

    .nav-links a {
      font-size: 16px;
      font-weight: 500;
      color: var(--text-body);
      position: relative;
      padding: 8px 0;
      transition: color var(--transition);
    }

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

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

    .nav-links a:hover::after {
      width: 100%;
    }

    .btn-nav {
      background: var(--primary);
      color: var(--white) !important;
      padding: 10px 24px !important;
      border-radius: var(--radius-sm);
      font-weight: 600;
      transition: background var(--transition), transform var(--transition);
      margin-left: 8px;
    }

    .btn-nav:hover {
      background: var(--primary-dark);
      transform: translateY(-2px);
    }

    .btn-nav::after {
      display: none;
    }

    .hamburger {
      display: none;
      flex-direction: column;
      gap: 6px;
      cursor: pointer;
      background: none;
      border: none;
      padding: 8px;
    }

    .hamburger span {
      display: block;
      width: 28px;
      height: 2px;
      background: var(--secondary);
      border-radius: 2px;
      transition: var(--transition);
    }

    .mobile-menu {
      display: none;
      position: fixed;
      top: 72px;
      left: 0;
      width: 100%;
      height: calc(100vh - 72px);
      background: var(--secondary);
      flex-direction: column;
      align-items: center;
      justify-content: center;
      gap: 32px;
      z-index: 99;
    }

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

    .mobile-menu a {
      color: var(--white);
      font-size: 20px;
      font-weight: 500;
    }

    .mobile-menu .btn-nav {
      background: var(--accent);
      color: var(--secondary) !important;
      font-weight: 700;
    }

    /* Hero */
    .hero {
      min-height: 100vh;
      display: flex;
      align-items: center;
      padding-top: 72px;
      background: linear-gradient(135deg, rgba(26,32,44,0.03) 0%, rgba(229,62,62,0.02) 100%);
    }

    .hero-grid {
      display: grid;
      grid-template-columns: 1.2fr 0.8fr;
      gap: 60px;
      align-items: center;
    }

    .hero-content h1 {
      font-size: 36px;
      line-height: 1.35;
      font-weight: 700;
      color: var(--text-primary);
      letter-spacing: 0.5px;
      margin-bottom: 20px;
    }

    .hero-content h1 span {
      color: var(--primary);
    }

    .hero-sub {
      font-size: 18px;
      color: var(--text-body);
      margin-bottom: 32px;
      max-width: 550px;
    }

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

    .btn-primary {
      background: linear-gradient(135deg, #E53E3E 0%, #C53030 100%);
      color: var(--white);
      padding: 14px 32px;
      border-radius: var(--radius-sm);
      font-weight: 600;
      font-size: 16px;
      border: none;
      cursor: pointer;
      transition: background var(--transition), transform var(--transition), box-shadow var(--transition);
      display: inline-flex;
      align-items: center;
      justify-content: center;
    }

    .btn-primary:hover {
      background: linear-gradient(135deg, #C53030 0%, #9B2C2C 100%);
      transform: translateY(-2px);
      box-shadow: var(--shadow-md);
    }

    .btn-outline {
      background: transparent;
      border: 2px solid var(--primary);
      color: var(--primary);
      padding: 14px 32px;
      border-radius: var(--radius-sm);
      font-weight: 600;
      font-size: 16px;
      cursor: pointer;
      transition: background var(--transition), color var(--transition), transform var(--transition);
    }

    .btn-outline:hover {
      background: rgba(229,62,62,0.08);
      transform: translateY(-2px);
    }

    .hero-visual {
      position: relative;
      border-radius: var(--radius-lg);
      overflow: hidden;
      box-shadow: var(--shadow-md);
    }

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

    /* 板块通用 */
    .section {
      padding: 90px 0;
    }

    .section-title {
      text-align: center;
      margin-bottom: 56px;
    }

    .section-title h2 {
      font-size: 28px;
      font-weight: 600;
      color: var(--text-primary);
      margin-bottom: 12px;
    }

    .section-title p {
      color: var(--text-muted);
      font-size: 16px;
    }

    /* 核心优势 */
    .advantages-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }

    .adv-card {
      background: var(--card-bg);
      border-radius: var(--radius-md);
      padding: 32px;
      box-shadow: var(--shadow-sm);
      transition: box-shadow var(--transition), transform var(--transition);
    }

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

    .adv-card.featured {
      grid-column: span 2;
      background: linear-gradient(135deg, #FFF5F5 0%, #FFFFFF 100%);
      border-left: 4px solid var(--primary);
    }

    .adv-icon {
      font-size: 32px;
      color: var(--primary);
      margin-bottom: 20px;
    }

    .adv-card h3 {
      font-size: 20px;
      font-weight: 600;
      color: var(--text-primary);
      margin-bottom: 10px;
    }

    .adv-card p {
      color: var(--text-body);
      font-size: 15px;
      line-height: 1.6;
    }

    /* 产品展示 */
    .products-grid {
      display: grid;
      grid-template-columns: repeat(2, 1fr);
      gap: 28px;
    }

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

    .product-card:hover {
      box-shadow: var(--shadow-md);
    }

    .product-img {
      overflow: hidden;
      aspect-ratio: 16/9;
    }

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

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

    .product-info {
      padding: 20px 24px 28px;
    }

    .product-info h3 {
      font-size: 20px;
      font-weight: 600;
      color: var(--text-primary);
      margin-bottom: 8px;
    }

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

    .tag {
      background: #F7F8FA;
      color: var(--primary);
      padding: 4px 12px;
      border-radius: 20px;
      font-size: 13px;
      font-weight: 500;
    }

    .product-desc {
      color: var(--text-body);
      font-size: 15px;
      margin-top: 8px;
    }

    /* 案例横向滚动 */
    .cases-scroll {
      display: flex;
      gap: 24px;
      overflow-x: auto;
      padding-bottom: 16px;
      scrollbar-width: thin;
      -webkit-overflow-scrolling: touch;
    }

    .case-card {
      min-width: 280px;
      background: var(--card-bg);
      border-radius: var(--radius-md);
      padding: 24px;
      box-shadow: var(--shadow-sm);
      flex-shrink: 0;
    }

    .case-thumb {
      width: 100%;
      aspect-ratio: 4/3;
      border-radius: var(--radius-sm);
      overflow: hidden;
      margin-bottom: 16px;
    }

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

    .case-stat {
      font-size: 36px;
      font-weight: 700;
      color: var(--accent);
      line-height: 1.2;
    }

    .case-label {
      color: var(--text-body);
      font-size: 15px;
      margin-top: 4px;
    }

    /* 方案对比 */
    .compare-table {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 20px;
      align-items: start;
    }

    .plan-card {
      background: var(--card-bg);
      border-radius: var(--radius-md);
      padding: 32px 24px;
      box-shadow: var(--shadow-sm);
      text-align: center;
      border: 2px solid transparent;
      transition: box-shadow var(--transition);
    }

    .plan-card.recommended {
      border-color: var(--primary);
      background: #FFF5F5;
      position: relative;
    }

    .badge {
      background: var(--accent);
      color: #1A202C;
      font-weight: 700;
      font-size: 13px;
      padding: 4px 14px;
      border-radius: 20px;
      display: inline-block;
      margin-bottom: 12px;
    }

    .plan-price {
      font-size: 32px;
      font-weight: 700;
      color: var(--text-primary);
      margin: 16px 0;
    }

    .plan-features {
      list-style: none;
      text-align: left;
      margin: 28px 0;
    }

    .plan-features li {
      padding: 8px 0;
      color: var(--text-body);
      display: flex;
      align-items: center;
      gap: 8px;
    }

    .plan-features i {
      color: var(--primary);
    }

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

    .faq-item {
      background: var(--card-bg);
      border-radius: var(--radius-md);
      margin-bottom: 12px;
      box-shadow: var(--shadow-sm);
      transition: background var(--transition);
    }

    .faq-question {
      padding: 20px 24px;
      display: flex;
      justify-content: space-between;
      align-items: center;
      font-weight: 600;
      color: var(--text-primary);
      cursor: pointer;
      font-size: 17px;
      user-select: none;
    }

    .faq-icon {
      transition: transform var(--transition);
      font-size: 20px;
      color: var(--primary);
    }

    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease, padding 0.3s ease;
      padding: 0 24px;
      color: var(--text-body);
    }

    .faq-item.active .faq-answer {
      max-height: 200px;
      padding: 0 24px 24px;
    }

    .faq-item.active .faq-icon {
      transform: rotate(45deg);
    }

    .faq-item.active {
      background: #FAFBFC;
    }

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

    .cta-title {
      color: var(--white);
      font-size: 28px;
      font-weight: 600;
      margin-bottom: 16px;
    }

    .cta-desc {
      color: var(--text-light);
      margin-bottom: 40px;
    }

    .cta-form {
      display: flex;
      gap: 16px;
      max-width: 700px;
      margin: 0 auto;
      flex-wrap: wrap;
      justify-content: center;
    }

    .cta-form input {
      flex: 1 1 200px;
      padding: 14px 20px;
      border-radius: var(--radius-sm);
      border: 1px solid #4A5568;
      background: #2D3748;
      color: white;
      font-size: 16px;
    }

    .cta-form input:focus {
      border-color: var(--accent);
      box-shadow: 0 0 0 3px rgba(246,173,85,0.25);
    }

    .btn-cta {
      background: var(--accent);
      color: #1A202C;
      font-weight: 700;
      padding: 14px 36px;
      border-radius: var(--radius-sm);
      border: none;
      cursor: pointer;
      transition: filter var(--transition), transform var(--transition);
    }

    .btn-cta:hover {
      filter: brightness(1.1);
      transform: translateY(-2px);
    }

    /* Footer */
    .footer {
      background: #111;
      color: #A0AEC0;
      padding: 60px 0 30px;
    }

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

    .footer h4 {
      color: white;
      margin-bottom: 20px;
    }

    .footer a {
      color: #A0AEC0;
      display: block;
      margin-bottom: 10px;
    }

    .footer a:hover {
      color: white;
    }

    .copyright {
      text-align: center;
      margin-top: 40px;
      font-size: 13px;
      color: #718096;
    }

    @media (max-width: 1024px) {
      .advantages-grid {
        grid-template-columns: repeat(2, 1fr);
      }
      .adv-card.featured {
        grid-column: span 2;
      }
      .footer-grid {
        grid-template-columns: repeat(2, 1fr);
      }
    }

    @media (max-width: 768px) {
      .nav-links {
        display: none;
      }
      .hamburger {
        display: flex;
      }
      .hero-grid {
        grid-template-columns: 1fr;
        text-align: center;
      }
      .hero-content h1 {
        font-size: 28px;
      }
      .hero-buttons {
        justify-content: center;
      }
      .advantages-grid {
        grid-template-columns: 1fr;
      }
      .adv-card.featured {
        grid-column: span 1;
      }
      .products-grid {
        grid-template-columns: 1fr;
      }
      .compare-table {
        grid-template-columns: 1fr;
        overflow-x: auto;
        display: flex;
        flex-wrap: nowrap;
      }
      .plan-card {
        min-width: 260px;
      }
      .cta-form {
        flex-direction: column;
        align-items: stretch;
      }
      .footer-grid {
        grid-template-columns: 1fr;
      }
    }