Change the logo colour for mobile hamburger menu - 7.1

I'm using a dynamic menu, which works for most of my pages, but with a couple of my pages (FAQs and Services), the first section is the same colour as my logo. I have managed to implement CSS to switch out the logo to a different colour for the affected pages. It works well, apart from with the hamburger menu on mobile. 

I have followed the instructions to replace the hamburger logo for affected pages, but it doesn't seem to be hiding the original logo properly, so I get two logos overlapping, giving a funny outline. Can someone help me by taking a look at the code and see what's going on?

Code has been implemented in the "Advanced" section of the specific page, and not the site-wide CSS panel.

Website: https://aspiring-dental.squarespace.com

Password: Aspiring-Dental-2023

<style> 
div.header-title-logo a {
content:url("https://static1.squarespace.com/static/64ae1056de93ab723f53c4f3/t/64c8726fe5dffc761d47c949/1690858095063/AspiringDental_Logo_RGB_Blue.png") !important;     
max-width: 300px;
}
 
// mobile menu //
/* hide current image */
body.header--menu-open .header-title-logo img {
    visibility: hidden;
}
  /* set new image on burger menu click */
  body.header--menu-open .header-title-logo a {
    background-image: url(https://static1.squarespace.com/static/64ae1056de93ab723f53c4f3/t/64c877652a73de35bf04a12a/1690859365906/AspiringDental_Logo_RGB_Cream.png);
    background-size: cover;
    background-repeat: no-repeat;
}
</style>

These are the original instructions I followed. Everything works, apart from Step 5

https://www.thecoastkit.com/blog/how-to-update-logo-on-different-pages

That worked perfectly. Thank you!! Really appreciate your help.