fx.css

::selection {
  background: deepskyblue;
  color: #101;
}

:focus {
  outline-color: currentColor;
}

.fx {
  color: #101;
  background-color: #bae;
  background-image: radial-gradient(
    #bae,
    mediumpurple,
    chocolate,
    rosybrown,
    violet,
    plum,
    orchid,
    peachpuff
  );
}

@media (prefers-color-scheme: dark) {
  .fx {
    color: linen;
    background-color: darkmagenta;
    background-image: radial-gradient(
      maroon,
      darkviolet,
      darkorchid,
      darkmagenta,
      indigo,
      purple
    );
  }
}