.board-collapse-canvas { overflow: hidden; }
.board-fragment-layer {
  position: absolute;
  z-index: 3;
  inset: 0;
  overflow: hidden;
  border-radius: 50%;
  pointer-events: none;
}
.board-fragment {
  position: absolute;
  display: block;
  box-shadow: inset -4px -4px 7px rgba(0,0,0,.22);
  will-change: transform,opacity,filter;
}
body.is-collapsing { overflow-x: hidden; }