How are those half-baked? No smooth transition for details/summary, maybe?
Dialog seems to work well enough with little to no javascript required:
<dialog>
<h3>Warning:</h3>
...
<button onclick='this.closest("dialog").close()'>Dismiss</button>
</dialog>
My personal bugbear is the date/time input - FF doesn't even show a click element for time, you have to type in the time.