/* 
点击切换显示隐藏
 */
var box = document.getElementById('box');
var btn = box.children[0];
var content = box.children[1];
// window.getComputedStyle(element, pseudoElement)		//element: 必需，要获取样式的元素。可以获取选定元素的样式
var contentStyle = window.getComputedStyle(box.children[1]);
console.log(contentStyle,'contentStyle')
btn.onclick = function() {
	btn.style.cursor = "pointer";   //鼠标移入按钮形状
	// content.style.display = contentStyle.display == "none" ? "block" : "none";
	if(contentStyle.display == "none"){
		content.style.display = "block";
	}else{
		content.style.display = "none";
	}
}