//1.定义focus事,绑定属性

<el-input

    v-model="headerInput"

    @focus="onInputFocus" 
　　@blur="onInputBlur":style="thisStyle"> 
</el-input>

thisStyle:'',

//2.获得焦点事件

onInputFocus(){
  let self = this;

　self.thisStyle="outline: 0;box-shadow: 0px 0px 10px 0px #ffffff;transition: border ease-in-out 0.15s,box-shadow ease-in-out 0.15s;-moz-transition:border ease-in-out 0.15s,box-shadow ease-in-out 0.15s;-webkit-transition:border ease-in-out 0.15s,box-shadow ease-in-out 0.15s;"

},

//3.失去焦点事件

onInputBlur(){
  let self = this;
  self.thisStyle = "width: 330px;"

},