Below 768px the panel fills the viewport and the rail becomes the horizontal
section strip the Web product uses: the title shares the first row with the
header actions and close control, the registered section cells scroll sideways
on the second, and the active section fills the rest. Cells keep their labels
whole and the strip scrolls instead of truncating, so a registrant's label
length or a longer section roster cannot wrap or clip a name.
The panel places its four seats (title, header, navigation, options) on one
grid, so the desktop rail keeps its 188px track and 64px first row. Preference
rows drop their 48px control gutter and the Appearance cubes share one row at
that width.
Saafo