How can I maximize the width of my Add to Cart button in Dawn?

I’d like my Add to Cart to fill the container at max width and no code I’ve tried worked so I’m not sure how to change this.

thediybridestore.com

Never mind, after a lot more searching, I finally found a code that worked.

Container of add to cart button set max-widht is 44rem. Please go to Online store > Themes > Edit code > open section-main-product.css, and find this line of code.

.product-form__buttons {
  max-width: 44rem;
}

Change to this

.product-form__buttons {
  max-width: 100%;
}