I'm kinda new to both CSS, and HTML. I've started to learn them around two days ago, and by editing the default MyBB template it helped me to understand how at least CSS works, and a bit of HTML since honestly said, I had no clue what the tags meant before, or how to construct them correctly so it's functioning.
Anyways, I've made this theme in a period of 5 hours I guess. I've not bothered with designing the buttons at all, so someone suggested me to implement CSS buttons which wasn't a bad idea after all.
Here's a live preview of it. I in no way advertise that forum, as you can see, nothing is really on there since it's literally a test site for our themes that me and my friend creates. Note that we're both newbies to that area.
Honestly, a carbon style for the body class wouldn't look great IMHO. A simple color always does its job. I've used the color black because it was easier to blend in the header(those scan lines) which I added.
Thank you for your feedback though, I appreciate it.