Remove button hover-colour in header

Hi Squarespace

I have a small problem. 

I'm trying to remove the button background colour in my header here (INSTAGRAM). I just want the text to change colour, like the navigation does on the left side. 

https://hexahedron-tuba-35nb.squarespace.com

PW: ANNA

Can you help? Thank you vey much in advance! 

Alastair

You can use this code to Website > Website Tools > Custom CSS

a.btn {
    background-color: transparent !important;
    color: #fff !important;
}

Wow - thank you very much! Perfect!