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

# Settings

- [Adding custom CSS](https://docs.sparkeditor.com/settings/adding-custom-css.md): In a few simple steps, learn how to add custom CSS to the email templates in the Spark Editor plugin
- [HTML content in Email](https://docs.sparkeditor.com/settings/html-content-in-email.md): Learn how to sort out the visible HTML content issue in your email with a few simple checks