This is a SemanticUI/FomanticUI theme that contains shared configuration and styles between our website and our application. Common configuration, colors, and styles all live here, and then both our application and website both load a secondary theme in addition.
Since FUI 2.9.3, multiple inheritance of themes become difficult. For now, this theme should be configured for each element/module/etc in theme.config:
... @button: "rtd-common"; ...
The Webpack and the rest of the respective theme.config files will load this theme as the primary theme, and use the rtd-site and rtd-application themes via siteFolder. This is actually fairly correct usage, though the original idea was to load multiple layers of themes.