How to make folders in menu transparent

Site URL: http://www.lauredemees.com/

Hello, 

I wanted to make the white boxes transparant, anyone knows how? I use the Marta-template :)

I tried following code in custom css:

#header { background: rgba(0,0,0,0.5); }

Thankyouthankyouthankyou

Add to Design > Custom CSS

/* Make dropdown folder to transparent */
span.Header-nav-folder {
    background-color: transparent !important;
}

Thank you!!!

❤️