yle>
</div>
<div class="shape">
<h5><span class="ez-toc-section" id="%E5%85%AB%E8%BE%B9%E5%BD%A2"></span>八边形<span class="ez-toc-section-end"></span></h5>
<div id="octagon"></div>
<style contenteditable=""> 
#octagon {
	width: 100px;
	height: 100px;
	background: #f66;
	position: relative;
}
#octagon:before {
	content: "";
	position: absolute;
	top: 0;
	left: 0;    
	border-bottom: 29px solid #f66;
	border-left: 29px solid #fff;
	border-right: 29px solid #fff;
	width: 42px;
	height: 0;
}
#octagon:after 