From OTRS - https://ticket.wikimedia.org/otrs/index.pl?Action=AgentTicketZoom;TicketID=10683826
Note - I am translating using google for this one
1. In Japanese
2. Go to settings, reading preferences
The text above 'adjust article text sizing' says "slider above"
The text says "slider below"
From the OTRS ticket (translated):
In the explanation about change of the size of the character size of the browsing setting, "slider above" is written, but since the slider is actually displayed under the sentence, "slider below" had better do it.