【サンプルHTML】

	<div id="panel-btn">
		<span id="panel-btn-icon"></span>
	</div>

【サンプルcss】
	.main-navigation{
		dusplay:none;
	}

	#panel-btn-icon, #panel-btn-icon:before, #panel-btn-icon:after {
    		background-color: #1F386C;
	}
	#panel-btn{
    		float: right;
    		width: 35px;
    		height: 35px;
    		display: block;
    		position: fixed;
    		top: 11px;
    		right: 13px;
	}
	#panel-btn:hover{
		cursor: pointer;
	}
	#panel-btn-icon{
		border-radius: 1px;
    		display: block;
    		position: absolute;
   		top: 25px;
    		right: 2px;
    		width: 30px;
    		height: 1px;
    		transition: .2s;
	}
	#panel-btn-icon:before, #panel-btn-icon:after{
		border-radius:1px;
		display: block;
		content: "";
		position: absolute;
		top: 50%;
		left: 0;
		width: 30px;
		height: 1px;
		transition: .3s;
	}
	#panel-btn-icon:before{
		margin-top: -10px;
	}
	#panel-btn-icon:after{
		margin-top: 8px;
	}
	#panel-btn .closing{
		background: transparent;
	}
	#panel-btn .closing:before, #panel-btn .closing:after{
		margin-top: 0;
	}
	#panel-btn .closing:before{
		transform: rotate(-45deg);
		-webkit-transform: rotate(-45deg);
	}
	#panel-btn .closing:after{
		transform: rotate(-135deg);
		-webkit-transform: rotate(-135deg);
	}


【jQuery】

	$("#panel-btn").click(function() {
	$(".main-navigation").stop().slideToggle(400);
	$("#panel-btn-icon").toggleClass("closing");
	return false;
});