# Add Extra CSS Styles

Source: `R/style_extra_css.R`
`style_extra_css.Rd`

Adds css elements to target `outfile`, typically a xaringanthemer css file. The `css` argument takes a list of CSS classes and definitions (see examples below) and appends CSS rules to `outfile`.

    style_extra_css(
      css,
      outfile = "xaringan-themer.css",
      append = TRUE,
      heading = "Extra CSS"
    )

## Arguments

css | A named list of CSS definitions each containing a named list of CSS property-value pairs, i.e. `list(".class-id" = list("css-property" = "value"))`
outfile | Customized xaringan CSS output file name, default is "xaringan-themer.css"
append | If `TRUE` output will be appended to `outfile`; otherwise, it will overwrite the contents of `outfile`.
heading | Heading added above extra CSS. Use `NULL` to disable.

## css list

The `css` input must be a named list of css properties and values within a named list of class identifiers, for example `list(".class-id" = list("css-property" = "value"))`.

## Examples

    style_extra_css(
      outfile = stdout(),
      css = list(
        ".red" = list(color = "red"),
        ".small" = list("font-size" = "90%"),
        ".full-width" = list(
          display = "flex",
          width = "100%",
          flex = "1 1 auto"
        )
      )
    )#>
    #>
    #> /* Extra CSS */
    #> .red {
    #>   color: red;
    #> }
    #> .small {
    #>   font-size: 90%;
    #> }
    #> .full-width {
    #>   display: flex;
    #>   width: 100%;
    #>   flex: 1 1 auto;
    #> }