Responsive Random Image CSS Grid Gallery

This image grid and image gallery are for displaying images of varying sizes. The grid can be used to link to other sites or pages pages and the gallery for displaying larger versions of the thumbnails.
The thumbnail images can have a border if required and there is a checkbox to to make then round/oval.
Images
The image which appears on page load should be cropped to the maximum width that it will be displayed at - in this case 800px. The slidshow images will have a maximum width equal to the width of the image file. They should be cropped to this width before importing into EverWeb.
Navigation
The slides are navigated using directional arrows or grab and drag when viewed on computers. There is an option to hide the arrows on mobile devices where the slides can be swiped.
Testing
Test the slideshow in the iOS Simulator using an iPhone in both portrait and landscape mode to make sure the slideshow images have a suitable aspect ratio.