Buy Now Button - Changing Size

Site URL: https://eat17delivery.co.uk/premium-brands-1

Hi there,

I have previous CSS code on my site that I am building that seems to have stopped working. If you click the link, the buy now button changes size when it is clicked. Any idea how I can force this so it's a fixed size before and after the customer clicks? This is just a dummy site before I populate with correct products so I need to change the styling.

Also, can you only have three products per line and does anyone have CSS to make the quantity box a little smaller?

Thanks in advance.