:root{
  /* Ink settles; it never bounces. */
  --ease-ink:cubic-bezier(.22,.61,.36,1); /* @kind other */
  --ease-out-soft:cubic-bezier(.16,.84,.44,1); /* @kind other */
  --ease-in-out-slow:cubic-bezier(.45,.05,.55,.95); /* @kind other */

  --duration-instant:120ms; /* @kind other */
  --duration-fast:200ms; /* @kind other */
  --duration-base:320ms; /* @kind other */
  --duration-slow:560ms; /* @kind other */
  --duration-reveal:900ms; /* @kind other */

  --transition-hover:color var(--duration-fast) var(--ease-ink),background-color var(--duration-fast) var(--ease-ink),border-color var(--duration-fast) var(--ease-ink); /* @kind other */
  --transition-reveal:opacity var(--duration-reveal) var(--ease-out-soft),transform var(--duration-reveal) var(--ease-out-soft); /* @kind other */
}