astro/.changeset/few-peas-hunt.md

@astrojs/markdoc	@astrojs/markdown-remark	astro
minor	minor	minor

Updates the internal shiki syntax highlighter to shikiji, an ESM-focused alternative that simplifies bundling and maintenance.

There are no new options and no changes to how you author code blocks and syntax highlighting.

Potentially breaking change: While this refactor should be transparent for most projects, the transition to shikiji now produces a smaller HTML markup by attaching a fallback color style to the pre or code element, instead of to the line span directly. For example:

Before:

<code class="astro-code" style="background-color: #24292e">
  <pre>
    <span class="line" style="color: #e1e4e8">my code</span>
  </pre>
</code>

After:

<code class="astro-code" style="background-color: #24292e; color: #e1e4e8">
  <pre>
    <span class="line">my code<span>
  </pre>
</code>

This does not affect the colors as the span will inherit the color from the parent, but if you're relying on a specific HTML markup, please check your site carefully after upgrading to verify the styles.