<1>.修改导航栏整体背景颜色 

/deep/ ul.el-menu-vertical-demo.el-menu {// 添加背景颜色background-image: linear-gradient(#175681, #112f57);}

<2>.修改点击菜单栏，背景颜色成白色

/deep/ li.el-menu-item.is-active {// 添加样式，只针对导航栏首菜单background-color: transparent;
 }

<3>修改首页以外的其他菜单栏点击时背景颜色以及字体颜色

.el-submenu /deep/.el-submenu__title:hover {color: #2e95fb !important;background: linear-gradient(#112f57, #122344) !important;
 }

 <4>修改主菜单栏下拉的子菜单栏的背景颜色

/deep/.el-submenu .el-menu-item {// 添加样式background-image: linear-gradient(#0099cc, #003366);
 }

*** 后续会继续更新