On my site, the amember css for the input fields is named the same as my theme. Would be best if the amember.css file had a unique css class for its input fields, which are larger than many, that being the padding here: select, textarea, input[type="text"], input[type="password"] As a result of having just an open application to this field, it will affect any other fields you may have elsewhere, e.g. a search box in a sidebar or header on the same page.