Hamburger desktop menu - cart icon not visible

Site URL: https://www.suzannefrear.co.uk/

Hey there, 

I am working on this website: https://www.suzannefrear.co.uk/

A while back we added some custom css to force the hamburger menu for desktop

Code is as follows:

// adding hamburger menu //
.header-burger { display:flex!important}
.header--menu-open .header-menu {opacity: 1!important;visibility: visible!important;}
.header-nav, .header-actions {visibility:hidden!important}
.header-menu-nav-item {line-height: 30px!important;}
// end adding hamburger menu //

It's working great except the cart icon isn't visible in the header and I need it to be as my client is now adding commerce to the site. When I go in to edit the header, the cart icon shows as being there but it's not visible.

Can someone please help? Thank you

Thank you so much @tuanphan!