You can specify an image or import a PDF page for the front cover and back cover of a document directly in your theme.
The front cover image is assigned using the
front-image key, and the back cover image using the
Both keys are set on the cover category and accept either a bare absolute or relative path or a target wrapped in an inline image macro as a value.
By default, a target file is resolved relative to the value of the
When the value is wrapped in an inline image macro, the target can be the absolute path or relative path to an image file or PDF file.
See Specify a background image in the theme for configuring a path that’s not relative to
The target can also be a data URI.
A cover image is handled like a background image, and the fit, width, and position attributes can be specified.
If a PDF file is assigned to the image macro, the first page of the file is used unless another page is specified by the
The PDF page will be imported as is.