{c('normal', 'inverse', 'title', 'middle', 'bottom')}

Slide Padding in `top right [bottom left]` format
Background image applied to each *and every* slide. Set `title_slide_background_image = "none"` to remove the background image from the title slide
Background image size, requires `background_image` to be set. If `background_image` is set, `background_size` will default to `cover` so the backround fills the screen. If both `background_image` and `background_position` are set, will default to 100 percent
Background image position, requires `background_image` to be set, and it is recommended to adjust `background_size`
Enables Shadow on text of inverse slides
Title Slide Background Image Size, defaults to "cover" if background image is set
Footnote text color (if `NA`, then it will be the same color as `text_color`)
Base Font Size for All Slide Elements (must be `px`)
Add background under slide title automatically for h1 header elements. If not enabled, use `class: header_background` to enable
Background Color for h1 Header with Background
Text Color for h1 Header with Background
Top Padding for Content in Slide with Header with Background
Slide Classes Where Header with Background will not be Applied
Use `google_font()` to specify body font
Body Text Font Family (xaringan default is `'Droid Serif'`)
Body Text Base Font (Total Failure Fallback)
Use `google_font()` to specify header font
Header Font Family (xaringan default is `'Yanone Kaffeesatz'`)
Use `google_font()` to specify code font

Monotone Base Color, works best with a strong color

Monotone Base Color, works best with a light color
Brightest color used, default is a very light version of `base_color`
Darkest color used, default is a very dark, version of `base_color`

Monotone base color, works best with a strong color

Monotone Base Color, works best with a light color.

{choose_dark_or_light(primary_color, darken_color(primary_color, 0.9), lighten_color(secondary_color, 0.99))}

Brightest color used, default is a very light version of `primary_color`
Darkest color used, default is a very dark version of `secondary_color`