app-systemImg/src/App.vue

<template>
  <index id="routers"></index>
  <router-view />
</template>

<script>
import index from "./views/index";
export default {
  name: "App",
  data() {
    return {
      title: "",
    };
  },
  components: { index },
};
</script>

<style>
#app {
}
/* 水平样式 */
.el-menu--horizontal > div > .el-submenu {
  float: left;
}
/* 一级菜单的样式 */
.el-menu--horizontal > div > .el-menu-item {
  float: left;
  height: 60px;
  line-height: 60px;
  margin: 0;
  border-bottom: 2px solid transparent;
  color: #909399;
}
/* 解决下图1 下拉三角图标 */
.el-menu--horizontal > div > .el-submenu .el-submenu__icon-arrow {
  position: static;
  vertical-align: middle;
  margin-left: 8px;
  margin-top: -3px;
}
/* 解决下图2 无下拉菜单时 不对齐问题 */
.el-menu--horizontal > div > .el-submenu .el-submenu__title {
  height: 60px;
  line-height: 60px;
  border-bottom: 2px solid transparent;
  color: #909399;
}
</style>