Use Vim to write the front-end code. YouCompleteMe and tern_for_vim are used for automatic completion. The js code can be incomplete normally, but when writing css, the attributes can be automatically completed, but the value of the attribute cannot be automatically completed.
The current css configuration is as follows:
autocmd FileType css setlocal omnifunc=csscomplete#CompleteCSSAttribute completion is as shown below: 
Attribute values cannot be incomplete as shown below:
![[Web front-end] Node.js quick start](https://img.php.cn/upload/course/000/000/067/662b5d34ba7c0227.png)
If you use YCM, this sentence should be unnecessary, if your YCM is configured to trigger css completion.
In this way, after you enter the attribute name and colon, and then space, the completion will be triggered, for example:
vertical-align:_