I was wondering if their is a Basic Coding Standard for HTML and CSS like PSR-01.
I tried googling and searching but didn't find any.
Have a look at these:
I would suggest looking at something like W3C standards.
They have code checkers on the site that you can run CSS and HTML through.
You can also check SMACSS - https://smacss.com/ it's not official or something but it's very useful architecture for building your websites. There is also methodology called BEM - https://en.bem.info/method/
来源：https://stackoverflow.com/questions/31401931/basic-coding-standard-for-html-and-css