Hi Usamah,
If you use your own modification of this: #editform textarea { border: inset 1px gray; background-color: #fdfdfd; padding: 2px; font-family: sans-serif; font-size: 110%; line-height: 1.5em; } In your monobook.css then you can change the text in the editform to whatever you want. It doesn't cause any problems that I've found and my users say it is much easier to read. Good luck on the why and your other question.
-----Original Message-----
1) Why MediaWiki uses mono fonts on all the <textarea> elements related to editing? And would changing that to other font(s) cause problems? I couldn't find where to edit this in the Monobook CSS. I now it can be simply set in the textarea's style rule, but why it doesn't inherit the font of the body, which is sans-serif?
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