About the comment mark issue in html_html/css_WEB-ITnose

is well known in HTML, you can use to comment!
However, there are currently two types of comments found in the tag body that cannot be commented in this way
1.

Some styles cannot be recognized by older versions of browsers. After adding this, they can be recognized. Go and take a look at the better programs made by others. The templates are all written like this and have good compatibility

As for what’s going on in JavaScript, I don’t know, and there’s no need to worry about it. There is nothing wrong with just following the rules. Some things have already been stipulated. You just need to remember how they are used. There is no reason why.