:root {
  --duration-instant: 80ms;
  --duration-fast:    140ms;
  --duration-normal:  200ms;
  --duration-slow:    320ms;

  /* No bounce, no overshoot. Signal motion is short and matter-of-fact. */
  --ease-standard: cubic-bezier(0.2, 0, 0.2, 1);
  --ease-out:      cubic-bezier(0.16, 1, 0.3, 1);
  --ease-in:       cubic-bezier(0.4, 0, 1, 1);

  --transition-control: background-color var(--duration-fast) var(--ease-standard),
                        border-color var(--duration-fast) var(--ease-standard),
                        color var(--duration-fast) var(--ease-standard),
                        box-shadow var(--duration-fast) var(--ease-standard);
}