.burger {
    z-index: 100;
    position: absolute;
    right: 20px;
    width: 20px;
    height: 20px;
    background: transparent;
    cursor: pointer;
    display: none;
}

.burger input {
    display: none;
}

.burger span {
    display: block;
    position: absolute;
    height: 2px;
    width: 100%;
    background: black;
    border-radius: 9px;
    opacity: 1;
    left: 0;
    transform: rotate(0deg);
    transition: .25s ease-in-out;
}

.burger span:nth-of-type(1) {
    top: 0px;
    transform-origin: left center;
}

.burger span:nth-of-type(2) {
    top: 50%;
    transform: translateY(-50%);
    transform-origin: left center;
}

.burger span:nth-of-type(3) {
    top: 100%;
    transform-origin: left center;
    transform: translateY(-100%);
}

.burger input:checked ~ span:nth-of-type(1) {
    transform: rotate(45deg);
    top: 0px;
    left: 5px;
}

.burger input:checked ~ span:nth-of-type(2) {
    width: 0%;
    opacity: 0;
}

.burger input:checked ~ span:nth-of-type(3) {
    transform: rotate(-45deg);
    top: 15px;
    left: 5px;
}

@media screen and (max-width: 760px) {
    .burger {
        display: block;
    }
}