Today I Learned:
IE11 doesn't handle
flex values in the same way that newer browsers do. Normally the value
flex: 1 is a shorthand for
flex-grow: 1. But in IE11, that affects the flex-basis, and it was throwing my sizing off.
I thought using the flex shorthand would be safe, and I normally consider shorthand an anti-pattern, since it makes refactors or overrides harder. But you never know what you'll find in Internet Explorer!