Dashboard Theming

Overview

Quarto Dashboards use same Bootstrap 5 based theming system as regular HTML documents (so themes you have built for HTML websites can also be used with dashboards). Use the theme option to choose a theme:

theme: cosmo

Quarto includes 25 themes from the Bootswatch project (for example, the website uses the cosmo theme). Available themes include:

Use of any of these themes via the theme option. For example:

format:
  dashboard:
    theme: united

In the following sections we’ll describe how you can customize these themes or create your own new themes.

Theme Options

You can do extensive customization of themes using Sass. Bootstrap defines over 1,400 Sass variables that control fonts, colors, padding, borders, and much more. You can see all of the variables here:

https://github.com/twbs/bootstrap/blob/main/scss/_variables.scss

Sass theme files can define both variables that globally set things like colors and fonts, as well as rules that define more fine grained behavior. To customize an existing Bootstrap theme with your own set of variables and/or rules, just provide the base theme and then your custom theme file(s):

theme:
  - cosmo
  - custom.scss

Your custom.scss file might look something like this:

/*-- scss:defaults --*/
$h2-font-size:          1.6rem !default;
$headings-font-weight:  500 !default;
$body-color:            $gray-700 !default;

/*-- scss:rules --*/
h1, h2, h3, h4, h5, h6 {
  text-shadow: -1px -1px 0 rgba(0, 0, 0, .3);
}

Note that the variables section is denoted by the /*-- scss:defaults --*/ comment and the rules section (where normal CSS rules go) is denoted by the /*-- scss:rules --*/ comment.

Custom Themes

You can naturally also create an entirely custom theme and provide only that (in this case you will inherit from the default Bootstrap theme):

theme: custom.scss

For example, here are the theme files for the 25 built-in Bootswatch themes:

https://github.com/quarto-dev/quarto-cli/tree/main/src/resources/formats/html/bootstrap/themes

You can read more about the custom theming design here.

Sass Variables

The following Sass Variables can be specified within SCSS files (note that these variables should always be prefixed with a $ and are specified within theme files rather than within YAML options):

Colors

Variable Notes
$body-bg The page background color.
$body-color The page text color.
$link-color The link color.
$input-bg The background color for HTML inputs.
$popover-bg The background color for popovers (for example, when a citation preview is shown).

Fonts

Variable Notes
$font-family-sans-serif The sans-serif font family for the page.
$font-family-monospace The monospace font family for the page.
$font-size-root The base font size for the page.
$toc-font-size The font size for the page TOC.

$h1-font-size

$h2-font-size

$h3-font-size

$h4-font-size

$h5-font-size

 Font sizes for the specified headings.

Code Blocks

Variable Notes
$code-block-border-left By default, Quarto does not display a left border on code blocks. Set this variable to a truthy value or a CSS color to enable the left border.
$code-block-border-left-style The style of the left border displayed on code blocks. Defaults to solid.
$code-block-border-left-size The thickness of the left border displayed on code blocks. Defaults to 3px;
$code-block-padding-left The amount of padding applied between the code and the border. Defaults to 0.6em.
$code-block-bg By default, Quarto sets a background on code blocks by adding transparency to the theme’s progress-bg color. Set this variable to truthy value or a CSS color.
$code-block-bg-padding The padding applied to the code block. Defaults to 0.4em.
$code-block-bg-alpha The amount to alter the transparency fo the progress-bg color. This is not used if an explicit background color is set. Defaults to -0.35.

Code Copy

You can also customize the colors of the button which appears for code-copy: true with the following variables:

Variable Notes
$btn-code-copy-color The color used for the copy button at the top right of code blocks.
$btn-code-copy-color-active The hover color used for the copy button at the top right of code blocks.

Inline Code

Variable Notes
$code-bg The background color of inline code. Defaults to a mix between the body-bg and body-color.
$code-color The text color of inline code. Defaults to a generated contrasting color against the code-bg.

Table of Contents

Variable Notes
$toc-color The color for table of contents text.
$toc-font-size The font-size for table of contents text.
$toc-active-border The left border color for the currently active table of contents item.
$toc-inactive-border The left border colors for inactive table of contents items.

Layout

Variable Notes
$content-padding-top Padding that should appear before the main content area (including the sidebar, content, and TOC.

Callouts

Variable Notes
$callout-border-width The left border width of callouts. Defaults to 5px.
$callout-border-scale The border color of callouts computed by shifting the callout color by this amount. Defaults to 0%.
$callout-icon-scale The color of the callout icon computed by shifting the callout color by this amount. Defaults to 10%.
$callout-margin-top The amount of top margin on the callout. Defaults to 1.25rem.
$callout-margin-bottom The amount of bottom margin on the callout. Defaults to 1.25rem.
$callout-color-<type>

The colors for the various types of callouts. Defaults:

type default
note $blue
tip $green
caution $orange
warning $yellow
important $red

In addition to the above Sass variables, Bootstrap itself supports hundreds of additional variables. You can learn more about Bootstrap’s use of Sass variables or review the raw variables and their default values.