demo · v136

HDR Gallery focus mode

The chromestatus motivation made interactive: a thumbnail gallery of HDR images. By default every tile renders constrained-high so no single bright image overwhelms the layout. Hover or tap a tile and only that tile flips to high — full HDR — the way Apple Photos and Lightroom treat HDR thumbs.

Probing…

Click a tile to "promote" it to dynamic-range-limit: high. On an HDR-capable display the promoted tile will visibly brighten beyond SDR white.

idle tile: inherits grid limit focused tile: high

the code

.gallery { dynamic-range-limit: constrained-high; }   /* default */
.gallery .focused { dynamic-range-limit: high; }      /* promote on demand */

why this angle

The sibling concept shows the three keywords as a static side-by-side — useful, but pure API surface. The motivation explicitly called out a use case the spec text does not: galleries with mixed HDR/SDR content where the contrast is jarring. This concept is that use case — six thumbs, all HDR-capable, normally constrained, individually promoted on focus. It's the exact UX Apple Photos ships on macOS.

see also