How to fill color on the output screen in html

Question

I need to fill clr red in the output screen

Answer 1

Just go to CSS tab and just type
body {
background-color:red;
}
still confused?? see the CSS part of my code LOL
https://code.sololearn.com/Woi0OiR8BaBP/?ref=app

Answer 2

thx

Answer 3

but the comment on output

Answer 4

now u can comment

Answer 5

with background-color