I tried to use jQuery slide() on a textarea element and it looked glitchy/janky so I tried to animate max-height. For some reason applying max-height: 0 !important reduces the height of the element but doesn’t bring it down to 0 – you can still see some of it.
I’ve removed the rows= attribute from the HTML on the element but the jQuery slide effect still looks really bad.
Just put display:none on textarea, because calculations of height are done by jquery, and on textarea call slide or slideToggle (see difference on following api link) function from jquery. That should do job for you.