Expanding Search

A header search that waits as an icon button and springs open into a full pill field on click or / from anywhere, growing from whichever edge its row anchors it to. The field takes focus, Escape clears and then folds it away, and it collapses when focus leaves while empty. Collapsed it's one labelled button, open a search form whose icon submits. Controlled or not, so a header can make room.