I've solved the issue!!
I delved into the css source code and changed the margin property there to auto. It seems like this base style sheet was overriding what I was trying to get my custom style sheet to do.
The grid approach didn't work. Anything else that you could suggest? I also should have mentioned above that I used those margin elements separately, not all together.
I'd tried:
margin: auto;
margin-left: 50%;
margin-right: 50%;
I've also tried using the padding element and it hasnt worked so far, I'll try the grid solution now.