Stage

A sunken box that shows media whole: any aspect, scaled down to fit, never cropped and never overflowing. Where a frame crops, a stage fits.

.stageCSS only

Examples

The same stage holds a 16:9, a 9:16 and a 1:1 canvas: each fits whole.

Drag the corner: the media follows the box, whichever side runs out first.

`.stage`	The sunken surface, its content centred. A size container, so its content can't size it: on its own it is φ⁵ ≈ 11rem tall, and it takes any size you give it, from `.golden`, a block size, or `[data-grow]` in a filling shell, where it grows but never shrinks below those 11rem.
`> canvas, > video, > img, > svg`	The media. Keeps its own proportions and is scaled down until it fits inside the stage's padding; never scaled up past its natural size.

The stage is a plain box and adds no semantics. Name what it shows: alt on an image, role="img" and an aria-label on a canvas, captions on a video.
Media is never cropped, so nothing in it is cut off at any size or zoom.