Headings that start with "c" get removed

[andrewpbray]

Discussed in #186

^{Originally posted by pwoodworth-jefcoats November 4, 2025}

On render, any heading that starts with the letter c gets removed from the HTML file.

---
format: closeread-html
---

:::{.cr-section}
## b

stuff here  
:::

non-cr

:::{.cr-section}
## c

stuff here  
:::

non-cr

:::{.cr-section}
## d

stuff here  
:::

non-cr

:::{.cr-section}
## b
## c
## d
:::

[jimjam-slam]

Can also reproduce! Doesn't happen with a regular format: html.

It seems like what's happening is the "c" heading is accidentally identified as a sticky:

But since nothing triggers that sticky, it's effectively invisible (as well as being I the wrong place).