The whole of css is difficult but it’s a non issue because you leave all the obsolete stuff out when using and learning css. Grid is for placement, box-model i

The whole of css is difficult but it’s a non issue because you leave all the obsolete stuff out when using and learning css. Grid is for placement, box-model is border-box, flex you don’t use and !important means your css is too complicated so go back and fix that. Of course your html does not have a single div, you don’t put nav into ul etc. and all is good.