Describe the bug

Hi

I use kill the newsletter feed, here as an example with Garmin (GPS/Watch manufaturer) Newsletter, also have this issue with other feeds.

When loading the feed through kill the newsletter (here an example: https://kill-the-newsletter.com/feeds/bgnybxntmbhhgl744t70.xml)

The Newsletter shows up weird and mostly white with the text also being white.

Using this feed rendere it seems to display much better with black text:
https://rss.app/feed/qCnpyOE5kP18vH5q?utm_source=rssviewer&utm_medium=website

To Reproduce

1. Create a new Kill My Newsletter
2. Subscribe with Garmin Newsletter (https://www.garmin.com/en-US/c/wearables-smartwatches/)
3. Wait a couple of Newsletters
4. See a barely readable text as color is white
5. Image:

Image from another Feed reader using same feed:

Expected behavior

A much better readable experience.

FreshRSS version

1.16.2

System information

• Database version: PostgreSQL
• PHP version: 8.2
• Installation type: Manual
• Web server type: Nginx
• Device: Dell Laptop
• OS: Windows 11
• Browser: Firefox 138.0.2
• Theme: Nord by @joelchrono12 with Dark Mode

Additional context

This issues has now happened with mutiple newsletters, so I made a report here.
I initially thought it's an issue with kill the newsletter, but as other readers show it fine, it seems to be a problem with freshrss?

Seems like Dark Mode is the problem, deavticating makes the text appear black again.
Though would still be nice if that issue could get fixed :)