transition-style/src/polygons/diamond-in-center.css

just add water clip-path mask transitions

@keyframes diamond-in-center {
  from {
    clip-path: var(--diamond-center-out);
  }
  to {
    clip-path: var(--diamond-center-in);
  }
}

[transition-style="in:diamond:center"] {
  --transition__duration: 1.5s;
  animation-name: diamond-in-center;
}