Click the map, then use the arrow keys. One tab stop for the whole map, then arrows walk the
features in reading order (top to bottom in bands, then left to right, because raw y-sorting
zigzags across a wide map and is disorienting). Home and End jump to the ends, Enter selects,
Escape leaves. A tab stop per feature would make a 3,000-county map unusable by keyboard, which
is the usual mistake. Above keyboardFeatureLimit features, walking is switched off
and the description plus the data table remain the accessible path.
a11y: { description: 'auto' } writes this from the spec and the data, because "a map
of Europe" tells a screen-reader user nothing they can act on. It names the map type, the number
of areas, the range, the class structure, the extremes and how many areas have no data.
…
Every arrow key replaces the text of a polite live region rather than appending to it, so fast travel does not flood the reader. This panel mirrors that region as you navigate.
(navigate with the arrow keys)
dataTable: true emits a real table alongside the map, visually hidden. For
assistive technology that cannot interpret spatial output at all, it is the only reliable
fallback. This is free in every licence tier, permanently.