Someone asked me about this a few days ago. And I remember having the same problem before too.
[b]Preview:[/b]
[img]http://localhostr.com/files/4e3d711862bae485a62b.jpg[/img]
If I ever wanted to customize the textarea or the text input tags of my forms, I would just insert a [b]style attribute[/b] directly into the tag itself instead of using css bcoz I could not make it work using css:
adjust to your desired settings
[quote]<textarea [color=red]style='width:[b]???[/b]px;height:[b]???[/b]px;font-family:[b]???[/b];background:#[b]??????[/b] url([b]BACKGROUND_URL[/b]);'[/color]>[/quote]
[b]-or-[/b]
[quote]<input type='text' [color=red]style='width:[b]???[/b]px;height:[b]???[/b]px;font-family:[b]???[/b];background:#[b]??????[/b] url(BACKGROUND_URL);'[/color]>[/quote]
Just replace the [b]???[/b] and the [b]BACKGROUND_URL[/b]. You're done