nav{ display: none; }

    .nav-open{
    	padding: 15px;
    	color: #00A0E9;
    	font-size: 11px;
    	line-height:normal;
    	font-family:'ヒラギノ角ゴ Pro W3','Hiragino Kaku Gothic Pro','Verdana',Verdana,'Helvetica',sans-serif;
		background:#fff;
    	position: relative;
    }
    .nav-open::before{/* 閉じている時 */
    	content: "+";
    	position: absolute;
    	left: 170px;
    }
    .nav-open.active::before{/* 開いている時 */
    	content: "-";
    }