/* roulang page: index */
:root {
      --primary: #0B1E1A;
      --accent: #E3F25B;
      --bg: #F9FAF7;
      --card-bg: #FFFFFF;
      --border-light: #E8EDE9;
      --text-primary: #0B1E1A;
      --text-body: #2E3A35;
      --text-muted: #6B7A73;
      --radius-lg: 12px;
      --radius-md: 8px;
      --radius-sm: 6px;
      --shadow-sm: 0 1px 3px rgba(0,0,0,0.04);
      --shadow-hover: 0 8px 24px rgba(11,30,26,0.08);
      --transition: 0.2s ease;
      --font-sans: "PingFang SC", "Microsoft YaHei", "Noto Sans SC", system-ui, -apple-system, sans-serif;
      --font-mono: "Inter", "SF Pro Display", system-ui;
    }

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

    body {
      font-family: var(--font-sans);
      background-color: var(--bg);
      color: var(--text-body);
      line-height: 1.7;
      font-size: 16px;
      -webkit-font-smoothing: antialiased;
      padding-top: 72px;
      padding-bottom: 56px;
    }

    @media (min-width: 1024px) {
      body {
        padding-bottom: 0;
      }
    }

    h1, h2, h3, h4 {
      font-weight: 700;
      letter-spacing: -0.02em;
      color: var(--text-primary);
      margin-bottom: 0.5rem;
    }

    h1 {
      font-size: 3.5rem;
      font-weight: 800;
      line-height: 1.2;
    }

    h2 {
      font-size: 2.2rem;
      margin-bottom: 1rem;
    }

    h3 {
      font-size: 1.4rem;
      font-weight: 600;
    }

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

    a {
      transition: var(--transition);
    }

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

    .container {
      max-width: 1200px;
      margin: 0 auto;
      padding: 0 16px;
    }

    @media (min-width: 640px) {
      .container {
        padding: 0 32px;
      }
    }

    /* 导航 */
    .desktop-nav {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 72px;
      background: rgba(249,250,247,0.9);
      backdrop-filter: blur(12px);
      z-index: 100;
      display: flex;
      align-items: center;
      justify-content: space-between;
      padding: 0 32px;
      border-bottom: 1px solid transparent;
      transition: background 0.3s, border-color 0.3s;
    }

    .desktop-nav.scrolled {
      background: rgba(11,30,26,0.95);
      border-bottom: 1px solid rgba(255,255,255,0.1);
    }

    .logo {
      font-size: 1.8rem;
      font-weight: 700;
      color: var(--primary);
      letter-spacing: -0.5px;
      text-decoration: none;
      display: flex;
      align-items: center;
      gap: 8px;
    }

    .desktop-nav.scrolled .logo {
      color: white;
    }

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

    .nav-links a {
      font-size: 15px;
      font-weight: 500;
      color: var(--text-primary);
      text-decoration: none;
      position: relative;
      padding: 4px 0;
      transition: color 0.2s;
    }

    .desktop-nav.scrolled .nav-links a {
      color: rgba(255,255,255,0.85);
    }

    .nav-links a::after {
      content: '';
      position: absolute;
      bottom: 0;
      left: 0;
      width: 0;
      height: 2px;
      background: var(--accent);
      transition: width 0.25s ease;
    }

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

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

    .nav-cta {
      background: transparent;
      border: 1.5px solid var(--primary);
      color: var(--primary);
      padding: 8px 20px;
      border-radius: var(--radius-md);
      font-weight: 600;
      font-size: 14px;
      transition: 0.2s;
      text-decoration: none;
      display: inline-block;
    }

    .desktop-nav.scrolled .nav-cta {
      border-color: white;
      color: white;
    }

    .nav-cta:hover {
      background: rgba(11,30,26,0.05);
      transform: translateY(-2px);
      box-shadow: var(--shadow-sm);
    }

    .hamburger {
      display: none;
      background: none;
      border: none;
      font-size: 1.8rem;
      color: var(--primary);
    }

    .desktop-nav.scrolled .hamburger {
      color: white;
    }

    @media (max-width: 1024px) {
      .nav-links {
        display: none;
      }
      .hamburger {
        display: block;
      }
      .desktop-nav {
        padding: 0 20px;
      }
    }

    /* 移动端菜单 */
    .mobile-menu {
      position: fixed;
      top: 72px;
      left: 0;
      width: 100%;
      background: rgba(11,30,26,0.98);
      backdrop-filter: blur(12px);
      flex-direction: column;
      padding: 24px;
      gap: 20px;
      display: none;
      z-index: 99;
    }

    .mobile-menu a {
      color: white;
      font-size: 18px;
      text-decoration: none;
      font-weight: 500;
    }

    /* 底部 Tab */
    .bottom-tab {
      position: fixed;
      bottom: 0;
      left: 0;
      width: 100%;
      height: 56px;
      background: #FFFFFF;
      border-top: 1px solid var(--border-light);
      display: flex;
      justify-content: space-around;
      align-items: center;
      z-index: 100;
    }

    @media (min-width: 1024px) {
      .bottom-tab {
        display: none;
      }
    }

    .tab-item {
      display: flex;
      flex-direction: column;
      align-items: center;
      color: var(--text-muted);
      font-size: 10px;
      text-decoration: none;
      transition: 0.2s;
      padding: 4px 0;
    }

    .tab-item i {
      font-size: 22px;
      margin-bottom: 2px;
    }

    .tab-item.active {
      color: var(--primary);
    }

    /* 区块间距 */
    section {
      padding: 64px 0;
    }

    @media (min-width: 1024px) {
      section {
        padding: 100px 0;
      }
    }

    /* Hero */
    .hero-grid {
      display: flex;
      align-items: center;
      gap: 40px;
    }

    .hero-left {
      flex: 55%;
    }

    .hero-right {
      flex: 45%;
    }

    .hero-right img {
      border-radius: 16px;
      box-shadow: var(--shadow-hover);
      width: 100%;
    }

    .hero-buttons {
      display: flex;
      gap: 16px;
      margin-top: 32px;
    }

    .btn-primary {
      background: var(--accent);
      color: var(--primary);
      border: none;
      padding: 14px 32px;
      border-radius: var(--radius-md);
      font-weight: 600;
      font-size: 16px;
      text-decoration: none;
      transition: 0.2s;
      display: inline-block;
    }

    .btn-primary:hover {
      filter: brightness(1.1);
      transform: translateY(-2px);
      box-shadow: var(--shadow-hover);
      color: var(--primary);
    }

    .btn-secondary {
      background: transparent;
      border: 1.5px solid var(--primary);
      color: var(--primary);
      padding: 14px 32px;
      border-radius: var(--radius-md);
      font-weight: 600;
      font-size: 16px;
      text-decoration: none;
      transition: 0.2s;
    }

    .btn-secondary:hover {
      background: rgba(11,30,26,0.05);
      transform: translateY(-2px);
    }

    /* 非对称网格 */
    .feature-grid {
      display: grid;
      grid-template-columns: 1fr 1fr 1fr;
      gap: 24px;
    }

    .feature-card {
      background: var(--card-bg);
      border-radius: var(--radius-lg);
      padding: 28px;
      box-shadow: var(--shadow-sm);
      border: 1px solid var(--border-light);
      transition: 0.3s;
    }

    .feature-card.large {
      grid-column: span 2;
    }

    .feature-card:hover {
      box-shadow: var(--shadow-hover);
      transform: translateY(-3px);
    }

    .feature-icon {
      font-size: 36px;
      color: var(--accent);
      margin-bottom: 16px;
    }

    /* 解决方案杂志流 */
    .solutions-layout {
      display: flex;
      gap: 40px;
    }

    .solutions-sidebar {
      flex: 1;
      display: flex;
      flex-direction: column;
      gap: 20px;
    }

    .solutions-main {
      flex: 2;
    }

    .solution-card {
      display: flex;
      gap: 20px;
      background: var(--card-bg);
      border-radius: var(--radius-lg);
      padding: 20px;
      margin-bottom: 20px;
      border: 1px solid var(--border-light);
    }

    /* 瀑布流 */
    .case-waterfall {
      column-count: 3;
      column-gap: 24px;
    }

    .case-card {
      break-inside: avoid;
      margin-bottom: 24px;
      background: var(--card-bg);
      border-radius: var(--radius-lg);
      overflow: hidden;
      box-shadow: var(--shadow-sm);
      transition: 0.2s;
    }

    .case-card img {
      width: 100%;
      transition: 0.3s;
    }

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

    /* 对比表 */
    .compare-table {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 0;
      background: var(--card-bg);
      border-radius: var(--radius-lg);
      overflow: hidden;
    }

    .compare-col {
      padding: 32px 24px;
    }

    .compare-col.highlight {
      background: #EFF5F1;
      border: 2px solid var(--accent);
      border-radius: var(--radius-lg);
      transform: scale(1.02);
      box-shadow: var(--shadow-hover);
    }

    /* FAQ */
    .faq-item {
      border-bottom: 1px solid var(--border-light);
      padding: 16px 0;
    }

    .faq-question {
      font-weight: 600;
      display: flex;
      align-items: center;
      gap: 16px;
      cursor: pointer;
    }

    /* 联系表单 */
    .contact-form input, .contact-form textarea {
      border: none;
      border-bottom: 1px solid #D0D7D3;
      border-radius: 0;
      padding: 12px 0;
      width: 100%;
      background: transparent;
      transition: 0.2s;
    }

    .contact-form input:focus, .contact-form textarea:focus {
      border-bottom-color: var(--accent);
      outline: none;
    }

    .footer {
      background: var(--primary);
      color: #BCC5C0;
      padding: 48px 0 24px;
    }

    @media (max-width: 640px) {
      h1 { font-size: 2.2rem; }
      .hero-grid { flex-direction: column; }
      .feature-grid { grid-template-columns: 1fr; }
      .feature-card.large { grid-column: span 1; }
      .solutions-layout { flex-direction: column; }
      .case-waterfall { column-count: 1; }
      .compare-table { grid-template-columns: 1fr; }
    }