[Broken Website] Beehiiv text unreadable

### Prerequisites

- [X] I [searched for any existing report](https://github.com/darkreader/darkreader/issues?q=is%3Aissue) about this website issue to avoid opening a duplicate.
- [X] I can reproduce this website issue in a new, unmodified web browser profile with Dark Reader installed as the only extension.

### Website Issue Description

Here are a few random links:
https://fossweekly.beehiiv.com/p/foss-weekly-47-godot-4-1-new-linux-laptop-and-phone-gnome-45-china-s-distro-and-more
https://opensourcewatch.beehiiv.com/p/suse-go-private
https://jasonfeifer.beehiiv.com/p/how-to-solve-big-problems

Beehiiv seems to be a newsletter platform where everyone has their own subdomain.

Basically with darkreader enabled the background is a very dark grey and the text color is a bit lighter grey but not really readable.

### Website Address

*.beehiiv.com

### Steps To Reproduce

1. Go to the links provided
2. Can't read the text properly

### Screenshots


### Operating System

Linux

### Web Browser name and version

Firefox 116

### Dark Reader version

4.9.65

### Additional Context

_No response_

Start by reproducing the issue in Firefox with Dark Reader enabled on the three linked Beehiiv pages, then inspect the page styles affecting the unreadable text. Done means the text has sufficient contrast and is readable across the reported *.beehiiv.com pages without degrading the dark background.

Written by the indexing model from the issue text.