Columns error

I'm trying to put a gallery page on our homepage of a video and accompanying side text (on https://atriummag.org/ under the featured slider). I'm using the columns block to do this because 'media and text' doesn't support video embeds, but the columns block isn't showing its normal settings. I can adjust 'width' but not margins, and because of this the video and text are stretching to the very ends of the screen. I'm thinking this is because of a !important property in the theme, but I couldn't pinpoint it down. Is this the issue? If not, how can I get the normal columns block back?