How can I add this style of background to the Search Banner?

[huynhthai824 (Sora &\)]

Hello,
How can i add this background search same page Whois Domain Tool:

Maybe change to other style in code pen:
example:

[jordan-vidrine]

You’ll first need to add some custom css to your site. The target should be: custom-search-banner. I would first start with that, and mess with the background css property and experiment with that.