:host {
  display: block;
  position: relative;
}

polyfill-next-selector { content: ':host > *'; }
::content > * {
  position: absolute;
  top: 0;
  right: 0;
  bottom: 0;
  left: 0;
}

polyfill-next-selector { content: ':host > *:not(.core-selected):not([animate])'; }
::content > *:not(.core-selected):not([animate]) {
  display: none !important;
}