How do I create a welcome banner like the one on this site?

[Steven]

This a custom theme component : GitHub - discourse/discourse-meta-banner

But I think it’s best to use a theme component made for the public, it’s easier to edit and customize :

Versatile Banner

This theme component is an evolution of previous banner efforts. The goal is to provide more ease and flexibility through the use of theme settings. [Banner_Theme] [mobile_demo] Below is a highlight of the features: Limit display to logged-in users or anonymous users Limit display to be exclusively mobile or desktop Limit display to specific pages Dismissible, expandable, and always visible options Full browser width option Color management Heading and column customization using HTML (see …