Hi Karen,
the Matukio backend is optimized for resolutions starting with 1600px (on desktop pcs!) - the default resolution of most displays is 1920px (Full HD) upwards and that for some years now.
But normally the layout (only the bookings overview form has because of 20 buttons some problems - will be fixed soon) should also work on smaller displays - we will have a menu minimize function with one of the next versions offering more size to the content. The template itself is responsive, but it has some glitches - we have further optimizations for that very high on our todo list
Detaching the layout back to the Joomla default one isn't possible without many code changes, because it's not only a CSS layout. There are so many things coming with that (bootstrap, javascript files etc.)
Kind regards,
Yves