How to display a Dialog dialog box using element in a vue component on full screen

< / div >

<el-dialog
  title=""
  :visible.sync="folderEditShow"
  width="30%"
  fullscreen
>
  <span></span>
  <span slot="footer" class="dialog-footer">
    <el-button @click="dialogVisible = false"> </el-button>
    <el-button type="primary" @click="dialogVisible = false"> </el-button>
  </span>
</el-dialog> 
  folderEdit(){
    this.folderEditShow = true
  }

how can I position the dialog box in the middle of the entire window?

Dialog element vue.js

Feb.27,2021

guess that the style is contaminated. You can right-click on dialog to check the elements and take a screenshot to