Change logo on hamburger menu

Site URL: https://www.psicodigitale.it/

Hello, I have a logo on my website that is white since the header background is of a dark colour (see image attached) but when I open the hamburger menu on mobile, the background becomes white and so my logo disappears (see second image attached).

I would like to substitute the bright logo with a dark one when I open the header menu on mobile. Note that the logo on my website is already been substitute with a custom css to add an svg instead of the png. This is the code that I'm currently using. Thank you all in advance. 

.header-title-logo img {
    visibility: hidden;
}
.header-title-logo a {
    background-image: url(https://static1.squarespace.com/static/60b1ecaf18ba745a54d1484d/t/61d2f9b0476ad24119bfebb3/1641216454121/Logo-Psicodigigitale-Colore.svg);
    background-size: contain;
    background-repeat: no-repeat;
    background-position: center center;
}

Hey @Nickss try this

.header--menu-open { 
  .header-title-logo img {
    content: url("URL HERE") !important;
    max-height:inherit !important;
  }
}

Hey thank you so much for this. Simply pasting your code didn't do the trick but I managed to make it work by coping and pasting my previous code inside the /header--menu-open{}. So to make it work now the whole code looks like this:

/*Make Squarespace Logo Invisible*/
.header-title-logo img {
    visibility: hidden;
}

/*Add my SVG logo*/
.header-title-logo a {
    background-image: url(https://static1.squarespace.com/static/60b1ecaf18ba745a54d1484d/t/61d2f9b0476ad24119bfebb3/1641216454121/Logo-Psicodigigitale-Colore.svg);
    background-size: contain;
    background-repeat: no-repeat;
    background-position: center center;
}

/*Add dark SVG logo on hamburger menu*/
.header--menu-open { 
	.header-title-logo a {
    background-image: url(https://static1.squarespace.com/static/60b1ecaf18ba745a54d1484d/t/61d2fa62c928c16903613f46/1641216632340/Logo-Psicodigitale-Dark-colorato.svg);
    background-size: contain;
    background-repeat: no-repeat;
    background-position: center center;
	}
}