Login fields are incorrectly sized on Safari and Internet Explorer

[RhysTedstone]

The login page for roundcube doesn't work properly on Safari and Internet Explorer.
I'm guessing it's because internet explorer is no longer supported, and Safari is bad, in every way.
But, nevertheless, basically everyone who has an IOS device uses safari.
I've attached an image of the login page as explaining them as "incorrectly sized" is a bit lacking.
Thanks in advance