I want these radio inputs to stretch across the screen, rather than one beneath the other:
HTML
In your case, you just need to remove the line breaks ( tags) between the elements - input elements are inline-block by default (in Chrome at least). (updated example).
Always
Never
Cost Change
I'd suggest using elements, though. In doing so, clicking on the label will check the element too. Either associate the 's for attribute with the 's id: (example)
..or wrap the elements around the elements directly: (example)
You can also get fancy and use the :checked pseudo class.