The Seven theme interferes with the Button style module. After applying the patch provided here: #1023564: Button Style on a per-theme basis D7, it is possible to disable button style for Seven. However with the following patch the (CSS) conflicts are solved. (For anyone who's interested).

CommentFileSizeAuthor
button_style-seven-theme.patch1.08 KBskilip
Support from Acquia helps fund testing for Drupal Acquia logo