.burger-icon{width:18px;height:14px;position:relative;display:inline-block;cursor:pointer}.burger-icon span{display:block;position:absolute;height:2px;width:100%;background:#000;transition:transform .3s ease}.burger-icon span:first-child{top:0}.burger-icon span:nth-child(2),.burger-icon span:nth-child(3){top:50%;transform:translateY(-50%)}.burger-icon span:nth-child(4){bottom:0}.burger-icon.open span:first-child{top:50%;transform:translateY(-50%) rotate(45deg)}.burger-icon.open span:nth-child(2){opacity:0}.burger-icon.open span:nth-child(3){top:50%;transform:translateY(-50%) rotate(-45deg)}.burger-icon.open span:nth-child(4){top:50%;transform:translateY(-50%) rotate(45deg)}