Install css formatting plugin in sublime

You can use HTML-CSS-JS Prettify for css formatting in sublime

The first step is to install HTML-CSS-JS Prettify

windows 环境下使用下面的命令
ctrl + shift + p
输入 install package 
点击 install package

Wait for a while, wait for a new pop-up box to appear, enter HTML-CSS-JS Prettify, press Enter,

wait for a few minutes, HTML-CSS-JS Prettify is installed

Using HTML-CSS-JS Prettify

1. Open the compressed css file
   
2. Select all css code
3. Right mouse button, find HTML-CSS-JS Prettify, click prettify code, complete