JS1k: The JavaScript code golfing competition

(function(a,b,c,d,e,f,g,h,i,j,k,l,m,n){if(!("open" in a.createElement(b))){l=a[k](b+">summary");h=a[k](b+":not([open])>"+i);while(h[++d])h[d].style[n]=g;a.addEventListener("click",function(o){m=o.target;d=c;while(l[++d])if(m==l[d]){j=m.parentNode[k](i);e=c;while(j[++e]&&(f=j[e].style))f[n]=f[n]==g?"":g}},false)}})(document,"details",-1,-1,0,0,"none",0,":not(summary)",0,"querySelectorAll",0,0,"display")

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

if (!("open" in document.createElement("details"))) {

	var summaries = document.querySelectorAll("details > summary");
	var notSummaries = document.querySelectorAll("details:not([open]) > :not(summary)");

	for (var i = 0, l = notSummaries.length; i < l; i++) {
		notSummaries[i].style.display = "none";
	}

	document.body.addEventListener("click", function(event) {

		var target = event.target;

		for (var i = 0, l = summaries.length; i < l; i++) {
			if (target == summaries[i]) {
				var other = target.parentNode.querySelectorAll(":not(summary)");
				for (var j = 0, k = other.length; j < k; j++) {
					other[j].style.display = other[j].style.display == "none"
						? ""
						: "none";
				}
			}
		}
	
	}, false);

}