I've posted an example of four different alignments of the spin buttons on
my GitHub site. One of them is the current layout with the buttons on the right. I've added the left, vertical, horizontal alignment options. Most of the changes are to the CSS with only some small tweaks to the code - mainly in the button HTML function.
I was curious if there is any interest in adding this to the Spinner widget. I noticed the left alignment is on the planning wiki. The other options seemed like useful choices that can add flexibility to the widget. I didn't want to submit a pull request unless there is interest.