How can I make friends with conflicting styles with bootstrap?

Question

CMS

How can you make friends with a ready-made layout with a bootstrap if their styles conflict?
First of all, this concerns the presence of box-sizing: border-box, due to which the sizes of the blocks can differ significantly.
I would like to use various "multipurpose html5 templates" in one cms, but bootstrap is always loaded there and all its widgets and modules use bootstrap layout.
And a question for passing Foundation connoisseurs: does it have the same problem?

Answer 1

yes, you can make friends, but you are tormented by redefining classes, checking cascading
for box-sizing and other fundamental things, I advise you to use reset.css or normalize.css