Fixes for the header on contacts.google.com in the Dark Gmail by DM userstyle:

[brian6932]

header .gb_4d{
	background-color: #2b2b2b;
    color: #efefef;
}
.gb_7d.gb_0e .gb_Re .gb_5e {
background-color: #1f1f1f;
border: 1px solid transparent;
-webkit-border-radius: 8px;
border-radius: 8px;
margin-left: auto;
margin-right: auto;
max-width: 720px;
position: relative;
-webkit-transition: background 100ms ease-in,width 100ms ease-out;
transition: background 100ms ease-in,width 100ms ease-out;
}

[DM164]

Thanks for contributing to the style.
Have a nice day and stay safe!