This is cool! I have always thought that the HTML <input type=range> input needed a dual-value implementation because that makes a lot of sense. Consider the use case "I want to filter products with at least X widgets but no more than Y".

However, I found a bug in Firefox I want to highlight:

Any time I click on a min or max handle they change change the value one step up or down.

If I make an effort to click in the dead center of the handle it does not change. If I click slightly to the left the selected value will decrease one step. If I click slightly on the right side of the handle it will increase.

I would expect the value to _only_ change when I make an actual action to change it by moving my mouse pointer with the button held down.