Typst CSS

Overview

The Typst CSS feature translates CSS properties into Typst properties, to allow similar styling between the HTML formats and the Typst format.

It is tuned for two use-cases:

HTML Tables styled by table packages
HTML <pre> tags representing console output with spans decorated with colors, e.g. from ANSI.

This document is designed for:

package developers who want to produce table or pre output which can be translated to Typst
extension developers who want to improve the translation of CSS properties, or add other CSS properties

It describes how Typst CSS works, how to enable and disable this feature and the related pre tag processing, troubleshooting, and adding or changing the translation filters.

How Typst CSS works

Unless table processing is disabled, tables in HTML raw blocks will be parsed into the Pandoc AST and then written by the output format.

When the output format is Typst, Quarto will juice the HTML input, annotating the HTML elements with CSS properties from the rules in any style sheets included in the HTML raw block. A Quarto post-processing filter translates the HTML attributes and CSS properties into attributes of the form typst:property or typst:text:property, and the Typst writer in Pandoc writes the output appropriately.

You can opt-in to have pre tags processed in the same way: see pre tag processing.

Supported Elements and Properties

Typst CSS works for the specific combinations of HTML elements and CSS properties below:

	span	div	table	td
background-color	✓	✓		✓
border¹				✓
color	✓	✓		✓
font-family		✓	✓
font-size		✓	✓
opacity	✓			✓
align²				✓

Disabling Typst CSS

The CSS-to-Typst Lua filter operates over the entire AST (not just tables and pre-tags). For troubleshooting purposes, the filter can be disabled with:

format:
  typst:
    css-property-processing: none

`pre` tag processing

pre-tag processing is intended for automatic translation of ANSI to Typst via HTML. Quarto does not currently capture ANSI output from execution, but this feature is available for packages and extensions.

pre tag processing is opt-in with html-pre-tag-processing="parse" on a div directly enclosing the HTML raw block:

::: {html-pre-tag-processing="parse"}

```{=html}
<pre>...</pre>
```
:::

Troubleshooting

To make sure that a package is outputting HTML tables that can be translated with Typst CSS, render the document with keep-md: true. Then check the .typst.md file for HTML Raw Blocks like

```{=html}
<table>
</table>
```

The raw block must contain an HTML <table> tag, which may be preceded by stylesheets (<style>).

Similarly, a raw block intended for pre tag processing must contain a <pre> tag, which may be preceded by stylesheets.

Modifying the translation

You can add your own Lua filters to add or change the translation of CSS properties into Typst properties.

Consult the Pandoc documentation for Typst property output and the source of the Lua filter which translates CSS properties to Typst.

You can override the Typst CSS Lua filter’s behavior by running your filter before it and removing CSS properties (untested). You can add support for other CSS properties by running your filter before or after the Typst CSS Lua filter.

Footnotes

border, border-left etc, border-width, border-style, border-color, border-left-width etc↩︎
text-align, vertical-align↩︎