Hide "All" category Marta template

I'm really searching for help to hide the "All" category that won't disappear from my shop navigation. I have tested all of the CSS codes I could find, but nothing seems to work.

Can anyone help? Thank you.

it's forwww.sofiesolstudio.com/shopMarta template.

@sofiesol Add to Home > Design > Custom CSS

ul.ProductList-filter-list li:first-child {
   display: none;
}

use this one

.ProductList-filter-list {
   display: none;
}