@Matthew_Butler it looks like your Read-Only link may have been disabled? Could you please re-share that?
This looks like a known Flexbox limitation where the widths are not set to 100% for certain elements.
The div-block-50 class and two of it’s child elements don’t have a width of 100% styled. Setting those to a width of 100% and changing the margin style to padding instead should clean that up but it’s difficult to test it further without a live Read-Only link. Can you please re-share that if you’re having any trouble with the implementation?