Describe the bug
When clicking the website/favicon in the main view in order to filter for a specific feed, a long list of feeds will be partially obscured beneath other folder items in the category tree. This only happens when the category is automatically expanded after filtering for a feed. It does not happen when manually expanding a category by clicking the dropdown toggle.

To Reproduce
Steps to reproduce the behavior:

1. Create a category with a very large number of feeds. I have 171 feeds in the category in question, so ~170 feeds should suffice. Name this category something like “A” so that it appears above other categories in the category tree.
2. Ensure that you have other categories that appear below the aforementioned category, i.e. “B”, “C”, “D”, etc.
3. Navigate to the main stream view. Click on a website title or favicon for one of the feeds so that it is filtered.
4. Category “A” will automatically expand in the category tree. A number of feeds will be obscured by categories “B”, “C”, “D”, ...

Expected behavior
The behavior should be the same as manually expanding a specific category by clicking on the dropdown toggle—all feeds for category “A” should be visible.

Environment information (please complete the following information):

• OS: OpenBSD 7.0 (happened in 6.9 as well)
• Browser: Firefox 97 (happened in earlier releases)
• FreshRSS version: 1.19.2 (bug occurred in earlier releases)
• Database version: postgres (PostgreSQL) 13.5
• PHP version: 8.0.14
• Installation type: Originally cloned from GitHub and updated several times using the built-in updater in the web interface

Additional context
The problem seems to stem entirely from this line of CSS. I'm not sure why this rule exists at all since deleting it doesn't cause any adverse issues while fixing the problem described here.

When manually clicking the dropdown toggle, an inline max-height rule is applied in order to accommodate the large number of items in the category. This rule appears to be calculated and it works fine, but it does not get applied when the category is automatically expanded by filtering for a specific feed. Perhaps this is because this code does not get executed when filtering for a feed, only when clicking the dropdown toggle?