let's say I have a very long line of inline styling, for example:
<input type="radio" style="visibility: hidden; position: absolute; foo: bar; baz: foo; etcetera: etc; and: more;">
and then I decide to make it more readable like this:
<input type="radio" style="visibility: hidden; position: absolute;
foo: bar; baz: foo; etcetera: etc; and: more;">
Does this affect the functionality or is it okay to break it into multiple lines like this?
It's fine. White space doesn't affect the browsers interpretation of that CSS or rendering of that element.