[Broken Website] [Brave] Dark Reader renders HostingDünyam website incorrectly (partial dark mode)

### 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

Hi,

Dark Reader is not working properly on the HostingDünyam website. When enabled, the page becomes partially dark and partially light, causing inconsistent rendering.

### Website Address

https://hostingdunyam.com.tr/

### Steps To Reproduce

1. Go to HostingDünyam website
2. Enable Dark Reader extension
3. Observe that only part of the page becomes dark

### Screenshots

### Operating System

Windows 11 Version 25H2 (Build 26200.8328)

### Web Browser name and version

Brave 1.90.121 Chromium: 148.0.7778.96 (64 bit)

### Dark Reader version

4.9.125

### Additional Context

It looks like the website uses mixed background styles (some elements have fixed white backgrounds or inline styles), which Dark Reader cannot fully override. This results in a split appearance where some sections are darkened while others remain light. The issue is especially noticeable on pages with cards, headers, or embedded panels.

Other websites work correctly, so the problem seems specific to how this site is styled (possibly hard-coded colors or missing support for CSS variables / prefers-color-scheme).