CSS Edit Checkout Button

Hey everyone!

I was wondering, how do I call out to edit the checkout button in the cart with CSS? Do I use #cart and then call for the button? If so, what is the exact code to call for it and edit it. As I'm trying to integrate the following code on the button click:

<button class='hoverme'> 
  <span>
    Click for confetti.
  </span>

</button>
<button class='hoverme'> 
  <span>
    Hover for confetti.
  </span>

</button>

<button class='hoverme'> 
  <span>
    Hover for confetxi.
  </span>

</button>

Hopefully you guys would be able to help me out! Thank you in advance! 🙂

Kind Regards

MIL