Animated hamburger menu with HTML and CSS

     /* Toggle functionality */

#toggle {
    position: absolute;
    left: -100%;
    top: -100%;
    opacity: 0;
}

label.toggle-container {
    display: inline !important;
}

#toggle:focus ~ .toggle-container .button-toggle {
    box-shadow: 0 0 0 0px rgba(12, 28, 38, 0.65), inset 0 0 0 24px rgba(12, 28, 38, 0.65);
}

/* Styles for the 'open' state, if the checkbox is checked*/

/* Any element you need to change the style if menu is open goes here, using the sibling selector (~) as follows

Making the "X" icon using `:before` and `:after` pseudo-elements */

#toggle:checked ~ .toggle-container .button-toggle {
    box-shadow: none;
    width: 23px;
    right: 10px;
}

#toggle:checked ~ .toggle-container .button-toggle:hover {
    box-shadow: none;
}

#toggle:checked ~ .toggle-container .button-toggle:before {
    transform: translateY(-50%) rotate(45deg) scale(1);
}

#toggle:checked ~ .toggle-container .button-toggle:after {
    transform: translateY(-50%) rotate(-45deg) scale(1);
}

#toggle:checked:active ~ .toggle-container .button-toggle {
    box-shadow: 0 0 0 550px rgba(0, 0, 0, 0.1), inset 0 0 0 20px rgba(0, 0, 0, 0.1), 0 0 0 8px rgba(0, 0, 0, 0.1), inset 0 0 0 20px rgba(0, 0, 0, 0.1);
}

#toggle:checked ~ .nav {
    margin-bottom: 100px;
    pointer-events: auto;
    transform: translate(0px, 50px);
}

/* Restoring nav items from "lines" in the menu icon */

#toggle:checked ~ .nav .nav-item {
    color: #fff;
    letter-spacing: 0;
    height: 40px;
    line-height: 40px;
    margin-top: 0;
    opacity: 1;
    transform: scaleY(1);
    transition: 0.5s, opacity 0.1s;
    font-size: 32px;
    font-family: AvantGardeBookBT;
}

/* Setting delays for the nav items in open transition */

#toggle:checked ~ .nav .nav-item:nth-child(1) {
    transition-delay: 0.15s;
}

#toggle:checked ~ .nav .nav-item:nth-child(1):before {
    transition-delay: 0.15s;
}

#toggle:checked ~ .nav .nav-item:nth-child(2) {
    transition-delay: 0.1s;
}

#toggle:checked ~ .nav .nav-item:nth-child(2):before {
    transition-delay: 0.1s;
}

#toggle:checked ~ .nav .nav-item:nth-child(3) {
    transition-delay: 0.05s;
}

#toggle:checked ~ .nav .nav-item:nth-child(3):before {
    transition-delay: 0.05s;
}

#toggle:checked ~ .nav .nav-item:nth-child(4) {
    transition-delay: 0s;
}

#toggle:checked ~ .nav .nav-item:nth-child(4):before {
    transition-delay: 0s;
}

#toggle:checked ~ .nav .nav-item:before {
    opacity: 0;
}

#toggle:checked ~ .dummy-content {
    padding-top: 30px;
}

#toggle:checked ~ .dummy-content:before {
    background-color: rgba(0, 0, 0, 0.3);
}


/* Toggle button */

.button-toggle {
    position: absolute;
    display: inline-block;
    width: 47px;
    height: 48px;
    margin: 11px;
    background-color: transparent;
    border: none;
    cursor: pointer;
    border-radius: 0;
    transition: 0.6s;
    right: 0;
    top: -10px;
    box-shadow: 0 0 0 0px rgba(12, 28, 38, 0.65), inset 0 0 0 24px rgba(12, 28, 38, 0.65);
    -webkit-backface-visibility: hidden;
}

.button-toggle:before,
.button-toggle:after {
    position: absolute;
    content: '';
    top: 50%;
    left: 0;
    width: 100%;
    height: 2px;
    background-color: #ffffff;
    border-radius: 5px;
    transition: 0.5s;
}

.button-toggle:before {
    transform: translateY(-50%) rotate(45deg) scale(0);
}

.button-toggle:after {
    transform: translateY(-50%) rotate(-45deg) scale(0);
}