<style>
 div.hpm_spoiler > div > .hpm_spoiler_body { display:none; }
 div.hpm_spoiler.offen > div > .hpm_spoiler_body { display:block; }
 div.hpm_spoiler.offen > div > .hpm_spoiler_headinput { background-color:yellow; }
 div.hpm_spoiler.offen > div:first-child::before { content:'- '; }
 div.hpm_spoiler > div:first-child::before { content:'+ ';	}
</style>
 
 

<script>
window.addEventListener("DOMContentLoaded",	function () {
		hpm_spoiler = function(div_sp)  { //* .. global hpm_spoiler() überschreiben
			div_sp.classList.toggle("offen");
			event.stopPropagation();
		} 
	}
</script>