dialog.sidebar {
  --duration: 200ms;

  transition: 
    translate var(--duration) ease-in-out,
    opacity    var(--duration) ease-in-out,
    scale     var(--duration) ease-in-out,
    height    var(--duration) ease-in-out,
    display   var(--duration) ease-in-out allow-discrete;

  overflow-y: auto; 
  position: fixed; 
  
  max-width: 80%; 
  width: 24rem; 
  height: 100%;
  max-height: 100vh;
  z-index: 100;
  box-shadow: 0 20px 40px -10px rgba(0, 0, 0, 0.18), 0 8px 24px -8px rgba(0, 0, 0, 0.12);
    
  left: 0; 
  bottom: 0;
  top: 0;
  right: auto; 
  margin: 0;
  
  &[open] {
    /* Pre-Entry State */
    @starting-style {
      translate: -100% 0;
      opacity: 0.8;
    }
  }
  /* Exiting State */
  &:not([open]) {
    translate: -100% 0;
    opacity: 0.8;
  }

  &::backdrop {
    background-color: rgba(0, 0, 0, 0);
    transition: background-color 300ms ease;
  }
  &[open]::backdrop {
    background-color: rgba(0, 0, 0, 0.2);
    @starting-style {
      background-color: rgba(0, 0, 0, 0);
    }
  }
}