@import url('https://fonts.googleapis.com/css?family=Oswald:400,700');

*{
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Oswald', sans-serif;
}

body{
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    background: #434750;
}

ul{
    position: relative;
    transform: skewY(-15deg);
}

ul li{
    position: relative;
    list-style: none;
    width: 12.5em;
    background: #3e3f46;
    padding: 0.9375em;
    z-index: var(--i);
    transition: 0.5s;
}

ul li:hover {
    background: #33a3ee;
    transform: translateX(-3.125em);/*translate(3.125em, 3.125em)*/
}

ul li::before {
    content: '';
    position: absolute;
    top: 0;
    left: -2.5em;
    width: 2.5em;
    height: 100%;
    background: #2e3133;
    transform-origin: right;
    transform: skewY(45deg);
    transition: 0.5s;
}

ul li:hover:before {
    background: #1f5378;
}

ul li::after {
    content: '';
    position: absolute;
    top: -2.5em;
    left: 0;
    width: 100%;
    height: 2.5em;
    background: #35383e;
    transform-origin: bottom;
    transform: skewX(45deg);
    transition: 0.5s;
    
}

ul li:first-child::after {
    content: 'itbt.org';
    display: flex;
    justify-content: center;
    align-items: center;
    color: #999;
    letter-spacing: 0.05em;
}

ul li:first-child:hover::after {
    color: #fff;
}

ul li:hover::after {
    background: #2982b9;
}

ul li a {
    text-decoration: none;
    color: #999;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    transition: 0.5s;
}

ul li:hover a {
    color: #fff;
}

ul li:last-child::after {
    box-shadow: -7.5em 7.5em 1.25em rgba(0,0,0,0.25);
}