I had the same problem ..
It is a bit of a pain because of responsive design and the length of different words, but mine were longer than left and right.
.. this is where to start ..
catalog/view/theme/default/stylesheet/styleheet.css
add these directives
div.radio, radio { display: inline; }
.radio input[type=radio], .radio-inline input[type=radio] { position: relative; }
I think that is everything, but its a good starting point ..
I solved mine by creating a module to allow for everything to be in a select dropdown - with images -
Then I just had a list of dropdowns
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