margins

Hey, I want to build a single page site with different background colors. Therefore I use groups. An outer group with width "full" and an inner group with a self build css-class "test" (because all encapsulated elements stick to full width...): .test { max-width: 55rem; margin-left: auto; margin-right: auto; } Unfortunately - on small screens - the margin of this inner group is A LITTLE BIG bigger than in your general stanard. What can I do? Thank you very much for your help (I know this is more a general support than a theme question...) Mirjam