// 1 Definitions focus things, binding properties
<el-input v-model="headerInput" @focus="onInputFocus"
@blur="onInputBlur":style="thisStyle">
</el-input>
thisStyle: '',
. // 2 gets the focus event
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. lost focus event
onInputBlur(){
let self = this;
self.thisStyle = "width: 330px;"
},