草稿

<style>
		.layui-layout-admin .layui-body {
			top: 5px !important;
			bottom: 44px;
			z-index: 201
		}
		.topLevelMenus>li:hover .divMenu{
			display: block;
		}
		.topLevelMenus>li::before{
			content: '';
			display: block;
			border-style: solid; 
			border- 10px 100px; 
			border-color:  transparent;
			position: absolute; left: 0; top: 45px;
			z-index: 2001;
		}
		.divMenu {
			position: absolute;
			top: 55px;
			left: 0px;
			 800px;
			height: 300px;
			background-color: rgb(194, 200, 218);
			display: none;
			padding: 5px;
			box-shadow: 0 2px 4px rgba(0,0,0,.12);
			border: 1px solid #d2d2d2;
			z-index: 100;
			border-radius: 5px;
		}
		
	</style>