your Word Press theme can override some of the CSS settings inherent in a Store Locator Plus “style” s. With well over a thousand WP themes, each developed and modified by different authors, developers and entities, who may or may not updates on a regular basis , it would be impossible to have individual locator layouts built into the SLP plugin, it isn’t one size fits all, there is coding and shortcodes to output various “styles:
There are themes and other plugins that have versions with outdated jquery and that can effect the outcome of how the plugin will work and display as well.
You can modify the search or page layout with ProPack and you can customize the layout, the size, with css
SLP Big Map plugin style,was tested on mobile devices for a directory for Word Camp Charleston in 2014 . (see blog)