That’s called minified css, I don’t see html in it but you can use something like Unminify or do it by hand to unminify the css.

If you’re saying it got rid of your html and put css in it’s place, there’s something much more wrong than we can tell with just a screenshot.

I’m new to the game ( around 1 month )
I accidentally pressed Start debugging and now my HTML code is messed up like this.

Is there any solution to revert this. thank you so much 🙂