Strange visual style for some applications in 13.1 on KDE desktop

I got surprised by end of life of 12.2 and quickly needed to jump into 13.1. Now I wonder a bit about the strange grapics style of some applications. More like Athena widgets in the 80s or Motif in the 90s...

While Emacs and pavucontrol are not parts of OpenSUSE or KDE desktop (probably Gtk, haven't checked) I think they looked better in 12.2. But the screenshot http://picpaste.com/buttons2-rc1V0BX0.png (*) is from Libreoffice and I understood that is well integrated to OpenSUSE.

Have a look at the square buttons inside the dialog, compared to the "nicely" rounded colors and shadows produced by KWin for the whole dialog.

Is this normal as other KDE desktop users are see it too? Or was I too "generous" when dropping some packages sounding like Gnome from the installation list? I assumed if the package is required it will be pulled in later, but maybe that assumption was wrong?

I'm not really into spending any time for theming and customizing. But this looks surprisingly "raw".


(*) For some reason inserting a pic into this forum does not work. Not sure whether this is another issue in my new desktop or a forum server issue.