Responsive design serves up different layouts based on CSS media
queries; typically, the display width is used. This is a fairly brute
force approach to providing a more usable display for mobile devices
based purely on using CSS to hide or shift around elements of the same
HTML.
Currently this is focused on making search results more usable, although
it will also improve the general header layout.
Functionality lost by this approach:
* Preferred library picker is hidden
* Facets are hidden
* Language picker is hidden
* Actions (such as add to list / place hold) for each result are hidden
Lots of room for improvement; for example, retaining functionality by
moving facets below the results, or making the language picker less
bulky, or moving actions under each search result.