Looping in @Graeme Rycyk but I have an idea for you. We don’t have a clear indicator of data-source in the HTML classes for the search result. Instead, you could try something like:
a.search-result[href*="support.gainsight.com"] {
background-color: #e6f7ff;
border: 1px solid #91d5ff;
padding: 8px;
margin-bottom: 5px;
display: block;
color: #1890ff;
}
This way you target the href of the external link being served in the results and subsequently, style those panels using the custom CSS feature. You likely will need to play with it because this particular style doesn’t match exactly to the search results page as I ran it as a test.
I hope this is helpful! In the meantime, we will consider this as an enhancement request for the search results styling so we make it easier to customize.