The body has a mysterious margin of 8px

First , You need to know why 8px Mysterious margin of ：
Many elements have one by default 8px Of margin, And the performance effect is different on different browsers

In the project , It's usually used reser.css Reset all Style sheets , It can be guaranteed under all browsers , The style of project presentation is consistent ：
（1） Apply... In the project ： stay asset Of css Insert reset.css file ,

// main.js
import @/assets/css/reset.css

   
    

   
    

（2） Or in demo Write it like this ：

<style> * {
         margin: 0; padding: 0; } </style>