Hello Rashida,
I've tried to apply this custom CSS, it appears to work.
Meanwhile I've noticed another issue. In com_content category pages (such as blog) I have broken design, take a look to the link I post please.
Comparing to the quickstart, I have just added articles and menu items. I've cheched the HTML of the articles, it looks fine. Joomla is updated to 4.2.6, Stellar template and Helix Framework to the latest available versions. If I set the default template to Cassiopeia (J4 default) everything works properly, no broken design.
Any clue how to fix this issue? May I send you a Super User account? (the website is not in production yet)
Thanks,
kind regards.