The gray line that you’re seeing is coming from the plugin/code that you added inside of the widget –
<div id="mapp0_links" class="mapp-map-links"></div>
The css that it’s using is this –
.mapp-map-links {
background-color: #F0F0F0;
border-top: 1px solid lightgray;
border-bottom: 1px solid lightgray;
}
So if thats a plugin you’re using, then you would have to override it by adding some code in your style.css file like this –
.mapp-map-links {
background-color: none !important;
border: none !important;
}