Weird gap between contents of page and the end of the site

[autodidacticAI]

I’m trying to get rid of this gap, I have a style setting the bgColor of the site to #F3F6F8 and for some reason there’s a big chunk which doesn’t change colors underneath the last div with content inside. I’ve tried everything I know from margin 0, padding 0, backgroundSize cover, …
Can anybody help?
My page is roughly:

layout div(
div(
    div
    div
    div
))