/* roulang page: index */
:root {
      --primary: #1A5FDC;
      --primary-dark: #1550c0;
      --accent: #FF6B35;
      --accent-light: #ff8c5a;
      --bg-page: #F8FAFC;
      --bg-card: #FFFFFF;
      --bg-hero: linear-gradient(135deg, #EFF6FF 0%, #F8FAFC 100%);
      --bg-cta: #EBF2FE;
      --footer-bg: #1E293B;
      --text-title: #0F172A;
      --text-body: #334155;
      --text-muted: #64748B;
      --text-footer: #CBD5E1;
      --border-light: #E2E8F0;
      --border-input: #CBD5E1;
      --shadow-card: 0 1px 3px rgba(0,0,0,0.06), 0 1px 2px rgba(0,0,0,0.04);
      --shadow-card-hover: 0 10px 25px rgba(0,0,0,0.1), 0 4px 10px rgba(0,0,0,0.05);
      --shadow-nav: 0 1px 0 #E2E8F0;
      --radius-card: 12px;
      --radius-btn: 8px;
      --radius-input: 6px;
      --font-family: "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", system-ui, -apple-system, sans-serif;
      --transition-fast: 0.2s ease;
    }

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

    body {
      font-family: var(--font-family);
      background-color: var(--bg-page);
      color: var(--text-body);
      line-height: 1.7;
      font-size: 1rem;
      -webkit-font-smoothing: antialiased;
    }

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

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

    button, input {
      font-family: inherit;
    }

    .container {
      max-width: 1280px;
      margin: 0 auto;
      padding: 0 1.5rem;
    }

    /* 导航 */
    .navbar {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      background: #fff;
      box-shadow: var(--shadow-nav);
      z-index: 50;
      height: 64px;
      display: flex;
      align-items: center;
    }

    .nav-brand {
      display: flex;
      align-items: center;
      gap: 0.5rem;
    }

    .nav-logo {
      width: 36px;
      height: 36px;
      background: url('/assets/images/backpic/logo.png') center/contain no-repeat;
      border-radius: 8px;
      display: flex;
      align-items: center;
      justify-content: center;
      font-weight: 700;
      color: var(--primary);
    }

    .nav-brand-text {
      font-size: 1.25rem;
      font-weight: 700;
      color: var(--primary);
      letter-spacing: 0.5px;
    }

    .nav-links {
      display: flex;
      align-items: center;
      gap: 2rem;
    }

    .nav-link {
      font-size: 0.95rem;
      font-weight: 500;
      color: #475569;
      position: relative;
      padding: 0.25rem 0;
      transition: color var(--transition-fast);
    }

    .nav-link::after {
      content: '';
      position: absolute;
      bottom: 0;
      left: 50%;
      transform: translateX(-50%);
      width: 0;
      height: 2px;
      background: var(--primary);
      transition: width var(--transition-fast);
    }

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

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

    .mobile-menu-btn {
      display: none;
      background: none;
      border: none;
      font-size: 1.5rem;
      color: var(--text-title);
      cursor: pointer;
    }

    /* 移动端菜单 */
    .mobile-drawer {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 100%;
      background: rgba(255,255,255,0.96);
      backdrop-filter: blur(8px);
      z-index: 60;
      display: flex;
      flex-direction: column;
      padding: 2rem;
      transform: translateX(-100%);
      transition: transform 0.3s ease;
    }

    .mobile-drawer.open {
      transform: translateX(0);
    }

    .mobile-drawer .nav-link {
      font-size: 1.25rem;
      padding: 1rem 0;
      border-bottom: 1px solid var(--border-light);
      color: var(--text-title);
    }

    /* 区块通用 */
    .section {
      padding: 5rem 0;
    }

    @media (max-width: 768px) {
      .section {
        padding: 3rem 0;
      }
      h1 {
        font-size: 1.875rem !important;
      }
      h2 {
        font-size: 1.5rem !important;
      }
    }

    .section-title {
      font-size: 1.875rem;
      font-weight: 700;
      color: var(--text-title);
      margin-bottom: 1.5rem;
      line-height: 1.3;
    }

    /* 卡片基础 */
    .card {
      background: var(--bg-card);
      border-radius: var(--radius-card);
      box-shadow: var(--shadow-card);
      transition: transform var(--transition-fast), box-shadow var(--transition-fast);
    }

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

    /* 按钮 */
    .btn-primary {
      background: var(--primary);
      color: white;
      padding: 0.75rem 2rem;
      border-radius: var(--radius-btn);
      font-weight: 600;
      display: inline-block;
      transition: background var(--transition-fast), transform var(--transition-fast);
      border: none;
    }

    .btn-primary:hover {
      background: var(--primary-dark);
      transform: scale(1.02);
    }

    .btn-outline {
      background: transparent;
      color: var(--primary);
      border: 1px solid var(--primary);
      padding: 0.75rem 2rem;
      border-radius: var(--radius-btn);
      font-weight: 600;
      transition: background var(--transition-fast);
    }

    .btn-outline:hover {
      background: rgba(26,95,220,0.05);
    }

    /* 表单 */
    .input-field {
      width: 100%;
      padding: 0.75rem;
      border: 1px solid var(--border-input);
      border-radius: var(--radius-input);
      font-size: 1rem;
      transition: border var(--transition-fast), box-shadow var(--transition-fast);
      background: #fff;
    }

    .input-field:focus {
      outline: none;
      border-color: var(--primary);
      box-shadow: 0 0 0 3px rgba(26,95,220,0.2);
    }

    /* 案例对比装饰 */
    .comparison-divider {
      width: 1px;
      background: var(--border-light);
    }

    @media (max-width: 768px) {
      .comparison-divider {
        width: 100%;
        height: 1px;
        margin: 1.5rem 0;
        background: dashed var(--border-light);
      }
    }