A theme for Omeka-S used by UO Libraries, based on the default theme.
This theme no longer requires, but heavily encourages, the use of the Universal Viewer module or Mirador.
In order for UV or Mirador to replace the default item viewer, the Blocks Disposition module must be installed and configured to not show either viewer.
CSS development uses NPM and Gulp to compile Sass. A full explanation can be found in the Omeka S developer documentation: Working with SASS and CSS.
This repository no longer includes packages required to run this process, because nodejs is a beast, the package lockfile triggers security warnings from github, and the process for generating CSS may change at any time (their documentation URLs sure do, at least).
When we need to do this again, we should document the process, preferably using a standalone package like the one the SASS creators built and maintain. Sheesh.
Look at the Omeka S Theme documentation.
You may find Omeka's upstream templates list useful. You can copy a template from upstream and make edits locally to overwrite the view output.