Checkboxes, radio buttons alternatives

I was recently working on styling forms. It is much harder to style the elements of the forms like for example: input, select, checkbox or radio button as it seems they are controlled by operating system (right?) And don't respond very well to CSS3.

So I went to youtube and took a look how they deal with checkboxes (for example when you add a song to one of your playlists) and... boom! they don't use checkboxes at all, instead they build everything with div elements.

So my question is: is to a common practices? It seems that it gives a lot of more freedom of how one could style the checkboxes. How about other form elements? It's really annoying that default form elements are not editable well with CSS.