Trying to make button lengths uniform on a Brine index page section

I'm having no luck affecting the button lengths on an index page in Brine.  I'm trying to make them all a uniform length- hopefully a percentage of the screen width, especially as it comes up on a phone (mimicking a link tree).

I've tried to use different kinds of ID blocks, and different button names in the CSS section.  I also tried doing that, bookending with <style></style> via both the index settings and the page/section settings under it.

This is one of the versions I tried using in the CSS section, trying to target the Index page:

#collection-64f128436e6003453dea704b
sqs-block-button-element--large sqs-button-element--secondary sqs-block-button-element {
  width:80% !important;
} 

Does anyone know why none of this is affecting the buttons?   (This is at www.demeriflowers.com/hello )

It looks like it worked! Thank you!