Hiding left & right arrows on slider

Site URL: http://magicalartssociety.squarespace.com

Hi there

Trying to hide the left & right arrows on the testimonials slider towards the bottom of the page.

Have tried below with no luck:

.Index-gallery-control--left svg,
.Index-gallery-control--right svg {
  display: none;
}

Pass is square for site.

Any help would be much appreciated.

Thanks

#testimonial .Index-gallery-control.Index-gallery-control {
    display: none;
}

Thank you!

Tuan Phan also offered the below should it help someone in future, too:

Add to Home > Design > Custom CSS

/* Remove slider testimonial arrows */
.homepage button.Index-gallery-control {
    display: none !important;
}