Change what? The font? The colors?
Regardless, that’s not how css works. Those selectors are all duplicated.
html .content and body .content will do the same thing, so one can be eliminated and can be rewritten as .content. Same for the .content span css. One can be eliminated and the other remove the body/html
I don’t think the height/width of 50% is going to work on html OR body, so I don’t know why they’re there.