Local Host not scrolling down

Hi, I have doing the HTML & CSS course. Ever since I reached the CSS box Model level, the local host page on the right side, where we would see the results of the instructions, does not scroll down.
It is important that I see the rest of the page and that it scroll down to know the results.
Please help.
Thank you

this may be a bug or you need to reset your zoom

I have tried resetting the zoom…It does not work…Currently I use Chrome… I tried opening it in Safari and Firefox…the same problem persists…the web browser does not scroll down…Following this problem somewhere on the net I read “If you have this bug; you can add “overflow: scroll” to “.main-wrap” with some browser extensions.” do you know what this is and how it is done…