Edit MOBILE hamburger navigation BUTTON

Site URL: https://jeanine-thompson.squarespace.com/

Hi there!

How do I edit the BUTTON on my mobile version hamburger dropdown navigation...I need to make it smaller, change the colour, and make it the petal style version (so it looks like the rest of the site's buttons) Please!

password: tuansqsp

It looks like you solved with this code?

.header-menu .header-menu-cta a {
    background: #f45ec6 !important;
    padding: 12px;
}