Most inputs draw a border and change its color on focus. In Magic Input the field lifts off the page, casts a shadow, and reveals a colored edge underneath. On submit, that same edge becomes a progress bar. None of it touches layout: it's three stacked layers and a handful of transform / opacity transitions.

The component renders one group wrapper containing three absolutely-positioned layers pinned to the same bounds: a blurred shadow, a colored edge, and the real <input> on top. At rest the shadow and edge are hidden; the field looks flat.

Because all three share inset-0, they stack exactly. The 3D illusion comes from how far apart they sit on the Y axis, and that distance is what the lift animates.

Focus lives on group-focus-within, so tabbing into the <input> drives every layer at once. The front translates up, the shadow drops down + fades in + blurs, and the edge fades in. The front moving one way while the shadow moves the other is what creates the depth.

The front uses an overshoot bezier (…,1.5) so it springs slightly past its target and settles. That overshoot is the "pop" on focus. The shadow rides a calmer …,1 curve over 600ms, because a shadow that snapped would read as a glitch. depth="always" moves the resting position to the lifted one, so the field is raised before you focus it.

The lift uses no box-shadow transition, no width or top animation and no clip-path. The shadow is a solid blurred span whose translate and opacity change; the edge only fades. transform and opacity are the two properties the browser can animate on the compositor without touching layout or paint, so the lift stays smooth even with several fields on screen.

const frontClass =
  "… [will-change:translate] " +
  "[transition:translate_600ms_cubic-bezier(0.3,0.7,0.4,1)] " +
  "motion-reduce:[transition:none] …";

will-change: translate promotes the layer up front so the first frame doesn't hitch, and motion-reduce:[transition:none] drops the whole thing to an instant state change for anyone who asks for reduced motion.

With rainbow (the default), focus swaps the edge and shadow fill for a single 200%-wide linear gradient, and animate-magic-rainbow slides background-position across it. The front stays neutral, so the color reads as a glowing edge under a plain field.

The colors are written out as a full literal because Tailwind's class scanner can't resolve a ${var} nested inside an arbitrary value. Only background-position animates; the gradient itself never re-renders.

Pass onSubmit (or submitButton) and the field grows a submit button. Drive status and it runs a lifecycle: loading → success / error. The same edge/shadow layer that draws the depth becomes the progress bar. Its background-size grows for determinate progress, or a segment bounces end to end for indeterminate, while the button's icon cross-fades arrow → ring → check.

The four submit icons (arrow, ring/spinner, check, X) are stacked in the same box. Only the active one is opacity-100 scale(1); the rest sit at opacity-0 scale(0.4) rotate(-35deg). Switching status changes which one is active, so they morph into each other instead of popping.

const iconClass = (active: boolean) =>
  active
    ? "… opacity-100 [transform:scale(1)_rotate(0deg)]"
    : "… opacity-0 [transform:scale(0.4)_rotate(-35deg)]";

Three stacked layers, a focus-driven lift, and a progress bar that is the depth layer with a different fill. transform and opacity do the work that borders and box-shadows usually fake.