.menu {
    list-style: none;
    margin: 0;
    padding: 0;
}

.menu li {
    cursor: pointer;
    padding: 6px 20px;
    font-size: 18px;
}

.menu li a {
    color: #ffffff;
    text-decoration: none;
}

button.menu-toggle {
    opacity: 0.6;
    background-color: transparent;
    position: fixed;
    top: 40px;
    right: 24px;
    z-index: 100000;
    border: none;
    width: 36px;
    height: 30px;
    outline: none;
    -webkit-transition: opacity 0.2s ease-out;
    transition: opacity 0.2s ease-out;
}

button.menu-toggle:before {
    content: "";
    position: absolute;
    top: 0;
    bottom: 0;
    left: 0;
    margin: auto;
    right: auto;
    width: 100%;
    background: -webkit-gradient(linear, left top, left bottom, from(#494949), color-stop(20%, #1B8BCB), color-stop(20%, transparent), color-stop(40%, transparent), color-stop(40%, #494949), color-stop(60%, #98B296), color-stop(60%, transparent), color-stop(80%, transparent), color-stop(80%, #98B296), to(#98B296));
    background: linear-gradient(to bottom, #494949, #494949 20%, transparent 20%, transparent 40%, #494949 40%, #494949 60%, transparent 60%, transparent 80%, #494949 80%, #494949 100%);
    -webkit-transition: opacity 0.2s ease-out, width 0.2s 0.2s ease-out;
    transition: opacity 0.2s ease-out, width 0.2s 0.2s ease-out;
}

.hamburger button:after {
    opacity: 0;
    content: '×';
    color: white;
    position: absolute;
    top: 16px;
    left: -4px;
    font-family: Arial, sans-serif;
    font-size: 76px;
    line-height: 0;
    -webkit-transition: opacity 0.4s ease-out;
    transition: opacity 0.4s ease-out;
}

.hamburger button:active {
    -webkit-transform: translateY(2px);
    transform: translateY(2px);
}

.hamburger button:hover {
    opacity: 1;
}

.open button {
    opacity: 1;
}

.open button:before {
    opacity: 0;
    width: 0;
}

.open button:after {
    opacity: 1;
    -webkit-transform: translate3d(0, 0, 0) rotate(360deg);
    transform: translate3d(0, 0, 0) rotate(360deg);
    -webkit-transition: opacity 0.4s 1s ease-out, -webkit-transform 0.4s 1s ease-out;
    transition: transform 0.4s 1s ease-out, opacity 0.4s 1s ease-out, -webkit-transform 0.4s 1s ease-out;
}

.hamburger nav {
    z-index: 10000;
    position: fixed;
    top: -100%;
    left: 0;
    width: 100%;
    height: 100%;
    -webkit-transform: translate3d(0, 0, 0);
    transform: translate3d(0, 0, 0);
    -webkit-backface-visibility: hidden;
    backface-visibility: hidden;
    overflow: hidden;
}

.hamburger nav:before {
    content: '';
    position: absolute;
    top: 0;
    right: 0;
    bottom: 0;
    left: 0;
    margin: auto;
    background: rgba(27, 139, 203, 0.98);
    width: 100%;
    height: 0;
    padding-bottom: 100%;
    border-radius: 100%;
    -webkit-transform: scale(0.04), translateY(9999px);
    transform: scale(0.04), translateY(9999px);
    overflow: hidden;
}

.open nav {
    top: 0;
}

.open nav:before {
    -webkit-animation: menu-animation 0.8s ease-out forwards;
    animation: menu-animation 0.8s ease-out forwards;
}

ul.menu {
    position: fixed;
    top: 50%;
    left: 50%;
    -webkit-transform: translate3d(-50%, -50%, 0);
    transform: translate3d(-50%, -50%, 0);
    -webkit-backface-visibility: hidden;
    backface-visibility: hidden;
    -webkit-perspective: 1000;
    perspective: 1000;
    color: white;
}

ul.menu li a {
    position: relative;
    z-index: 2;
}

ul.menu li {
    opacity: 0;
    text-align: center;
    -webkit-transform: translate3d(0, 36px, 0);
    transform: translate3d(0, 36px, 0);
}

ul.menu li:before {
    content: '';
    position: absolute;
    top: 0;
    right: 0;
    bottom: 0;
    margin: auto;
    left: auto;
    background-color: white;
    height: 100%;
    width: 0;
    overflow: hidden;
    -webkit-transition: width 0.14s ease-out;
    transition: width 0.14s ease-out;
}

ul.menu li:after {
    opacity: 0;
    content: attr(data-text);
    position: absolute;
    top: 0;
    right: 0;
    bottom: 0;
    left: 0;
    margin: auto;
    color: #1B8BCB;
    overflow: hidden;
    -webkit-transform: translate(-24px, 6px);
    transform: translate(-24px, 6px);
    -webkit-transition: opacity 0.1s ease-out, -webkit-transform 0.1s ease-out;
    transition: transform 0.1s ease-out, opacity 0.1s ease-out, -webkit-transform 0.1s ease-out;
}

ul.menu li:hover:before {
    left: 0;
    right: auto;
    width: 100%;
}

ul.menu li:hover:after {
    opacity: 1;
    padding: 0 20px;
    -webkit-transform: translate(0px, 6px);
    transform: translate(0px, 6px);
    -webkit-transition: opacity 0.2s 0.14s ease-out, -webkit-transform 0.2s 0.14s ease-out;
    transition: transform 0.2s 0.14s ease-out, opacity 0.2s 0.14s ease-out, -webkit-transform 0.2s 0.14s ease-out;
}

.open ul.menu li {
    opacity: 1;
    -webkit-transform: translate3d(0, 0, 0);
    transform: translate3d(0, 0, 0);
    -webkit-transition: opacity 0.2s ease-out, -webkit-transform 0.2s ease-out;
    transition: transform 0.2s ease-out, opacity 0.2s ease-out, -webkit-transform 0.2s ease-out;
}

.open ul.menu li:nth-child(1) {
    -webkit-transition-delay: 0.75s;
    transition-delay: 0.75s;
}

.open ul.menu li:nth-child(2) {
    -webkit-transition-delay: 0.85s;
    transition-delay: 0.85s;
}

.open ul.menu li:nth-child(3) {
    -webkit-transition-delay: 0.95s;
    transition-delay: 0.95s;
}

.open ul.menu li:nth-child(4) {
    -webkit-transition-delay: 1.05s;
    transition-delay: 1.05s;
}

.open ul.menu li:nth-child(5) {
    -webkit-transition-delay: 1.05s;
    transition-delay: 1.05s;
}

article {
    padding: 24px;
    max-width: 600px;
    margin: 60px auto;
    -webkit-transition: 0.2s ease-out;
    transition: 0.2s ease-out;
}

.open article {
    -webkit-transform: scale(0.92);
    transform: scale(0.92);
    -webkit-transition: -webkit-transform 0.2s 0.41s ease-out;
    transition: -webkit-transform 0.2s 0.41s ease-out;
    transition: transform 0.2s 0.41s ease-out, -webkit-transform 0.2s 0.41s ease-out;
}

@-webkit-keyframes menu-animation {
    0% {
        opacity: 0;
        -webkit-transform: scale(0.04) translateY(300%);
        transform: scale(0.04) translateY(300%);
    }
    40% {
        -webkit-transform: scale(0.04) translateY(0);
        transform: scale(0.04) translateY(0);
        -webkit-transition: ease-out;
        transition: ease-out;
    }
    40% {
        -webkit-transform: scale(0.04) translateY(0);
        transform: scale(0.04) translateY(0);
    }
    60% {
        opacity: 1;
        -webkit-transform: scale(0.02) translateY(0px);
        transform: scale(0.02) translateY(0px);
    }
    61% {
        -webkit-transform: scale(0.04);
        transform: scale(0.04);
    }
    99.9% {
        height: 0;
        padding-bottom: 100%;
        border-radius: 100%;
    }
    100% {
        -webkit-transform: scale(2);
        transform: scale(2);
        height: 100%;
        padding-bottom: 0;
        border-radius: 0;
    }
}

@keyframes menu-animation {
    0% {
        opacity: 0;
        -webkit-transform: scale(0.04) translateY(300%);
        transform: scale(0.04) translateY(300%);
    }
    40% {
        -webkit-transform: scale(0.04) translateY(0);
        transform: scale(0.04) translateY(0);
        -webkit-transition: ease-out;
        transition: ease-out;
    }
    40% {
        -webkit-transform: scale(0.04) translateY(0);
        transform: scale(0.04) translateY(0);
    }
    60% {
        opacity: 1;
        -webkit-transform: scale(0.02) translateY(0px);
        transform: scale(0.02) translateY(0px);
    }
    61% {
        -webkit-transform: scale(0.04);
        transform: scale(0.04);
    }
    99.9% {
        height: 0;
        padding-bottom: 100%;
        border-radius: 100%;
    }
    100% {
        -webkit-transform: scale(2);
        transform: scale(2);
        height: 100%;
        padding-bottom: 0;
        border-radius: 0;
    }
}