Panels
Basic
Panel should typically be used with the default border. Adding context should be done sparingly.
Footer button
Add .panel-footer-btn to a .panel-footer rendered as a <button> to turn the foot of a card into a single full-width action (e.g. an "Upload invoice" button). .panel-footer supplies the padding, background, and top border; .panel-footer-btn adds the button reset plus hover, active, disabled, and focus-ring states.