Steps to reproduce:
- Go to https://doc.wikimedia.org/oojs-ui/master/demos/?page=widgets&theme=wikimediaui&direction=ltr&platform=desktop, scroll down to "NumberInputWidget (0–1, step by .1, page by .25)"
- Enter "1".
- Press the down arrow key 10 times.
Expected: You end with 0.
Actual (Firefox): You reach 0.0000000000000001
Actual (Vivaldi): Rounding errors show up even before you should reach 0.