CSS for navigation boxes, matrix questions?

After customising quite a few surveys in Qualtrics, there are some elements that I've repeatedly struggled to adjust to my full satisfaction. Does anyone know of a canonical reference document that shows the CSS relating to Next and Back buttons (especially their position - I can only ever get them to show in the bottom-right of each page, next to one another)?

I'm also having difficulty with matrix questions - I can't figure out the CSS that controls the 'fade on hover' behaviour for alternate lines. I have a darker shade behind every other statement / ranking line, which currently fades to white on mouse-over and I'd like to disable this behaviour.

Any help appreciated!