When you resize your browser below 720 pixels wide, this style will make the IRCCloud interface more compact - the sidebar will be collapsed to show only the blue tabs that appear beside channels with unread messages. Hovering over the tabs will expand the sidebar to its original size.
Resizing below 640 pixels wide will also hide the list of users.

Changelog:
1.2: Updated for IRCCloud Alpha; moved collapsed sidebar over by a pixel
1.1.1: fix for "Logout" being cut off and user list getting stuck after installing
1.1: added the ability to choose the window sizes
1.0: initial release