Custom CSS Navigation Icon - doesn't work

Hello everyone 🙂

I changed the dropdown menu to an icon ( three stripes) but it only works on the homepage. For example on https://www.studiollots.com/projekte it doesn't appear anymore, the whole dropdown menu disappears.

@media only screen and (min-width:640px) { 
  .header-actions-action--social .icon--fill:nth-of-type(1) {
    svg {
      display:none;
    }    
    background-image: url(https://static1.squarespace.com/static/626849f9d4b34577d12db0c6/t/65df612385cc5440368eb5d0/1709138498868/konversation.png);    
    background-size: 100%;    
    background-repeat: no-repeat;  
  } 
  
}  

  
  
.header-nav-item[href*=menu],
.mobile-overlay-nav-item[href*=menu] {
  position: relative;
  color: transparent !important;
}
div.header-nav-item [href="/menu"] {content: '';
    background: url(https://static1.squarespace.com/static/626849f9d4b34577d12db0c6/t/65df612362122e038032071c/1709138498825/burger-menu.pnghttps://static1.squarespace.com/static/65df3b2b0c9ed76ee88da410/t/65df50c9d74e483842ee2b9f/1709134025253/burger-menu.png) no-repeat;
    background-size: cover;
    height: 100%;
    color: transparent !important;
    background-position: center center;
}

Use this code under

div.header-nav-item [href="/menu"] {
    content: '';
    background: url(https://static1.squarespace.com/static/626849f9d4b34577d12db0c6/t/65df612362122e038032071c/1709138498825/burger-menu.pnghttps://static1.squarespace.com/static/65df3b2b0c9ed76ee88da410/t/65df50c9d74e483842ee2b9f/1709134025253/burger-menu.png) no-repeat !important;
    background-size: cover !important;
    height: 100% !important;
    color: transparent !important;
    background-position: center center !important;
}