el-collapse-item平行放置按钮 平行显示

 

 html

css 

@import url("//unpkg.com/element-ui@2.15.8/lib/theme-chalk/index.css");

js 

var Main = {
    data() {
      return {
        activeNames: ['1']
      };
    },
    methods: {
      handleChange(val) {
        console.log(val);
      }
    }
  }
var Ctor = Vue.extend(Main)
new Ctor().$mount('#app')