html, body, #cesiumContainer {
  width:100%; height:100%; margin:0; padding:0; overflow:hidden;
  font-family:sans-serif;
}
#popup {
  position:absolute; background:rgba(0,0,0,0.7); color:#fff;
  padding:6px 8px; border-radius:4px; pointer-events:none;
  font-size:14px; z-index:1;
}
.hidden { display:none; }