<div>
  <button type="button" aria-haspopup="dialog" aria-controls="popup-id" aria-expanded="false">open dialog</button>
  <div id="popup-id">
    <!-- popup content goes here -->
  </div>
</div>

button {
  all: unset;
  background: white;
  border-radius: 0.5rem;
  border: 1px solid #e2e8f0;
  box-shadow: 0 1px 3px rgb(0 0 0 / 0.1);
  font-size: 0.875rem;
  font-weight: 500;
  height: 2rem;
  padding: 0 1rem;
  outline: revert;
}