Content area text gets styled as s2

Sometimes, text in blog posts which has been created by editors, gets the “s2” class:
<p class="s2"><span style="font-size: inherit;">Aber zurück zu den ...</span></p>

This is very strange as the text is in the content area whereas the class “s2” is used for the sidebar.

This leads to the problem that the text is hidden on mobile devices where the sidebar is hidden.

Can anyone explain to me this behaviour and tell me how this can be avoided?

Regards

• This topic was modified 2 years, 10 months ago by Abid.
• This topic was modified 2 years, 10 months ago by Abid.
• This topic was modified 2 years, 10 months ago by Abid.

The page I need help with: [log in to see the link]