Stack
.stack is a grid with one area. Every child takes it. The cell is as tall as the tallest child, so swapping children with data-show moves nothing else.
States in one footprint
Riverwalk FestliveLockport TastingplannedHarbor Marketlate
A veil over a chart
.veil — a glass card over its stack sibling, the content centred.
A caption on a frame
venueRiverwalk Festthe layer fills the frame
<div class="stack">
<div class="column" data-show="$state == 'loading'" style="display: none;">…</div>
<div class="column" data-show="$state == 'content'">…</div>
<div class="alert inf" data-show="$state == 'empty'" style="display: none;">…</div>
</div>