layout-imposter

A positioning helper for overlays, modals, and fixed UI elements. Uses CSS transforms for centering without requiring JavaScript calculations.

Attributes

Attribute	Values	Default	Description
`data-layout-fixed`	(boolean)	—	Position relative to the viewport instead of the containing block.
`data-layout-margin`	`s`, `m`, `l`, `xl`	—	Inset from the edges when pinned to one.
`data-layout-position`	`center`, `top`, `bottom`, `start`, `end`, `top-start`, `top-end`, `bottom-start`, `bottom-end`	`center`	Where to place the overlay.
`data-layout-contain`	(boolean)	—	Keep the overlay within the viewport, minus the margin, when fixed.

The imposter positions itself within a positioned ancestor (or viewport when fixed).

The data-layout-position attribute controls placement within the container.