/* roulang page: index */
/* 基础重置与设计变量 */
    :root {
      --primary-deep: #0F4C5C;
      --primary-dark: #0A3A47;
      --accent-green: #2D6A4F;
      --accent-green-light: #3D8B65;
      --gray-50: #F9FAFB;
      --gray-100: #F3F4F6;
      --gray-200: #E5E7EB;
      --gray-600: #6B7280;
      --gray-700: #374151;
      --gray-800: #1F2937;
      --gray-900: #111827;
      --radius-md: 12px;
      --shadow-sm: 0 1px 2px 0 rgba(0,0,0,0.05);
      --shadow-md: 0 4px 6px -1px rgba(0,0,0,0.06), 0 2px 4px -1px rgba(0,0,0,0.04);
      --shadow-lg: 0 10px 25px -5px rgba(0,0,0,0.08), 0 8px 10px -6px rgba(0,0,0,0.02);
      --transition-base: 200ms ease-in-out;
    }
    * {
      box-sizing: border-box;
    }
    body {
      font-family: 'Inter', 'PingFang SC', 'Microsoft YaHei', system-ui, -apple-system, sans-serif;
      margin: 0;
      background-color: #ffffff;
      color: #111827;
      line-height: 1.6;
      -webkit-font-smoothing: antialiased;
    }
    img {
      max-width: 100%;
      height: auto;
      display: block;
    }
    a {
      text-decoration: none;
      color: inherit;
    }
    button, input {
      font-family: inherit;
    }
    .container-main {
      max-width: 1280px;
      margin-left: auto;
      margin-right: auto;
      padding-left: 1.5rem;
      padding-right: 1.5rem;
    }
    @media (max-width: 640px) {
      .container-main {
        padding-left: 1rem;
        padding-right: 1rem;
      }
    }

    /* 导航自定义 */
    .nav-link {
      position: relative;
      transition: color var(--transition-base);
    }
    .nav-link.active {
      color: var(--primary-deep);
      font-weight: 600;
    }
    .nav-link.active::after {
      content: '';
      position: absolute;
      bottom: -4px;
      left: 0;
      width: 100%;
      height: 2px;
      background-color: var(--primary-deep);
      border-radius: 4px;
    }
    .mobile-menu {
      transition: opacity 0.3s ease, transform 0.3s ease;
    }

    /* 浮动动画 */
    @keyframes float {
      0% { transform: translateY(0px); }
      50% { transform: translateY(-8px); }
      100% { transform: translateY(0px); }
    }
    .float-animation {
      animation: float 3s ease-in-out infinite;
    }

    /* 数字递增无额外样式，由js控制 */
    .counter-digit {
      font-variant-numeric: tabular-nums;
    }

    /* 手风琴动画 */
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease, opacity 0.3s ease;
      opacity: 0;
    }
    .faq-item.open .faq-answer {
      max-height: 20rem;
      opacity: 1;
    }
    .faq-icon {
      transition: transform 0.3s ease;
    }
    .faq-item.open .faq-icon {
      transform: rotate(45deg);
    }

    /* 服务卡片差异化 */
    .card-a {
      border-left: 4px solid var(--primary-deep) !important;
    }
    .card-b {
      border-top: 6px solid var(--accent-green) !important;
    }
    .card-c {
      box-shadow: var(--shadow-lg);
    }
    .card-c:hover {
      box-shadow: 0 20px 30px -12px rgba(0,0,0,0.12);
      transform: translateY(-4px);
      transition: all var(--transition-base);
    }

    /* 对比表右侧高亮 */
    .compare-right {
      background-color: rgba(15, 76, 92, 0.04);
    }

    /* 按钮动效 */
    .btn-primary {
      background-color: var(--primary-deep);
      color: white;
      border-radius: 0.5rem;
      padding: 0.75rem 1.5rem;
      font-weight: 600;
      transition: all var(--transition-base);
      display: inline-flex;
      align-items: center;
      justify-content: center;
    }
    .btn-primary:hover {
      background-color: var(--primary-dark);
      transform: scale(1.02);
    }
    .btn-primary:active {
      transform: scale(0.98);
    }
    .btn-outline {
      background: transparent;
      border: 1px solid var(--primary-deep);
      color: var(--primary-deep);
      border-radius: 0.5rem;
      padding: 0.75rem 1.5rem;
      font-weight: 600;
      transition: all var(--transition-base);
      display: inline-flex;
      align-items: center;
      justify-content: center;
    }
    .btn-outline:hover {
      background-color: rgba(15, 76, 92, 0.06);
      transform: scale(1.02);
    }
    .btn-accent {
      background-color: var(--accent-green);
      color: white;
      border-radius: 0.5rem;
      padding: 0.75rem 1.5rem;
      font-weight: 600;
      transition: all var(--transition-base);
    }
    .btn-accent:hover {
      background-color: var(--accent-green-light);
      transform: scale(1.02);
    }
    .btn-accent:active {
      transform: scale(0.98);
    }

    /* 输入框焦点 */
    input:focus {
      outline: none;
      border-color: var(--primary-deep);
      box-shadow: 0 0 0 3px rgba(15, 76, 92, 0.15);
    }