/* make containers capable of holding shine */
.shinny-effect {
  position: relative;
  overflow: hidden;
}

/* shine layers */
.shinny-effect::before,
.shinny-effect::after {
  content: "";
  position: absolute;
  top: 50%;
  left: 50%;
  width: 25%;
  height: 150%;
  background: linear-gradient(
    120deg,
    rgba(255, 255, 255, 0) 0%,
    rgba(255, 255, 255, 0.8) 50%,
    rgba(255, 255, 255, 0) 100%
  );
  transform: translate(-50%, -50%) rotate(25deg);
  opacity: 0;
  pointer-events: none;
  z-index: 1000;
}

/* hover trigger */
.shinny-effect:hover::before {
  animation: toTopRight 2.5s ease forwards;
}

.shinny-effect:hover::after {
  animation: toBottomLeft 2.5s ease forwards;
}

/* ↗ center → exact top-right edge */
@keyframes toTopRight {
  0% {
    transform: translate(-50%, -50%) rotate(25deg) translate(0, 0);
    opacity: 1;
  }
  100% {
    transform: translate(-50%, -50%) rotate(25deg)
      translate(calc(50vw), calc(-50vh));
    opacity: 0;
  }
}

/* ↙ center → exact bottom-left edge */
@keyframes toBottomLeft {
  0% {
    transform: translate(-50%, -50%) rotate(25deg) translate(0, 0);
    opacity: 1;
  }
  100% {
    transform: translate(-50%, -50%) rotate(25deg)
      translate(calc(-50vw), calc(50vh));
    opacity: 0;
  }
}