> For the complete documentation index, see [llms.txt](https://docs.mosaic.js.org/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.mosaic.js.org/themes.md).

# Themes

- [Parent theme system](https://docs.mosaic.js.org/themes/extensions-and-themes.md): Mosaic introduces a concept of "themes"
- [File shadowing](https://docs.mosaic.js.org/themes/parent-themes.md): Build projects on top of projects