In the “Additional CSS” section of the dashboard add this:
body:not(.home) .custom-logo-link {
display: block;
position: relative;
}
body:not(.home) .custom-logo-link:before {
/* Permalink - use to edit and share this gradient: https://colorzilla.com/gradient-editor/#000000+0,000000+78&0.65+0,0+78 */
background: -moz-radial-gradient(center, ellipse cover, rgba(0,0,0,0.65) 0%, rgba(0,0,0,0) 78%); /* FF3.6-15 */
background: -webkit-radial-gradient(center, ellipse cover, rgba(0,0,0,0.65) 0%,rgba(0,0,0,0) 78%); /* Chrome10-25,Safari5.1-6 */
background: radial-gradient(ellipse at center, rgba(0,0,0,0.65) 0%,rgba(0,0,0,0) 78%); /* W3C, IE10+, FF16+, Chrome26+, Opera12+, Safari7+ */
filter: progid:DXImageTransform.Microsoft.gradient( startColorstr='#a6000000', endColorstr='#00000000',GradientType=1 ); /* IE6-9 fallback on horizontal gradient */
bottom: 0;
content: '';
height: 100%;
left: 0;
position: absolute;
text-decoration: none;
-webkit-transition: opacity 0.2s;
transition: opacity 0.2s;
width: 100%;
z-index: -1;
}
body:not(.home) .custom-logo-link:before:focus,
body:not(.home) .custom-logo-link:before:hover {
opacity: 1;
}
https://codex.www.ads-software.com/CSS#Custom_CSS_in_WordPress