what do you mean by "comment boxes"? And what exactly are you trying to achieve? I can probably help since I'm good with css. LMK or post more info.

Well, those boxes are called textareas, so if you look at a page's source code that has them, you'll see them as <textarea></textarea>. Double check the page's source code first. But if you want to style textareas, do this -

textarea {
styling here;
}

Single-line boxes, like when you enter a user and password to log into a site, are called inputs.