[Broken Website] avito.ru messages

### 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

The site has a pinned message window. The black theme on this window is applied only when you expand it, turn off the dark theme and then turn it on.

Dark theme on start:

### Website Address

avito.ru

### Steps To Reproduce

Open avito.ru
login
it is necessary to have active chats

### Screenshots

Dark theme on start:



Intresting - "onhover" turns fragments to dark theme:

After disable and enablint darkreader on active tab - all normalised:

### Operating System

Linux 6.8.0-51-generic #52-Ubuntu

### Web Browser name and version

Opera beta 116.0.5366.13

### Dark Reader version

4.9.96

### Additional Context

_No response_