>a[href]::before {content: "<a href='" attr(href) "'>"}</style>

<p>The <code>attr()</code> function, see <a href='https://developer.mozilla.org/en-US/docs/Web/CSS/attr'>mozilla docs</a> is a nifty trick, "supported" since CSS 2.</p>


<p>The only other style that is special is "style" itself, which has to include an escape character to avoid being taken literally.</p>

<style>
style::before {content:'<style>'}
style::after {content:'<\/style>'}
</style>


<aside>I like to think that may be a parser bug cre