Changing behavior after click on "Add to Cart" button

For whatever reason, I'm getting a weird AJAX behavior when I click the "Add to Cart" button on one of my product pages. (You can try it for yourself if you go to beta.siegefitness.com/store/products and pick any of the items.) When you choose an available option and click "Add to Cart," the entire quantity field/add button/variant dropdown disappear, there's a weird green flash, and then the field and button reappear.

I'd really like to make that not happen; in fact, I'd love it if clicking "Add to Cart" took one directly to the shopping cart page. Is there any way to do that?