.viewport-menu {
  position: fixed;
  z-index: 1000;
  min-width: 184px;
  max-width: calc(100vw - 16px);
  max-height: calc(100vh - 16px);
  overflow-y: auto;
  padding: 5px;
  border: 1px solid rgba(170, 198, 213, .3);
  border-radius: 9px;
  background: rgba(23, 37, 47, .96);
  box-shadow: 0 10px 30px rgba(0, 0, 0, .35);
  backdrop-filter: blur(10px);
  color: #ecf4f7;
}
.viewport-menu[hidden] { display: none; }
.viewport-menu button {
  display: block;
  width: 100%;
  padding: 10px 12px;
  border: 0;
  border-radius: 5px;
  background: transparent;
  color: inherit;
  font: 13px/1.4 system-ui, sans-serif;
  text-align: left;
  cursor: pointer;
}
.viewport-menu button:not(:disabled):hover,
.viewport-menu button:focus-visible { background: rgba(109, 191, 218, .18); outline: 1px solid rgba(109, 191, 218, .5); }
.viewport-menu button:disabled { opacity: .4; cursor: default; }