@import url('https://fonts.googleapis.com/css?family=Poppins&display=swap');

body{
    margin: 0;
    padding: 0;
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    font-family: 'Poppins', sans-serif;
    background: linear-gradient(#fff 0%, #fff 50%, #42a8f9 50%, #42a8f9 100%);
}

.navigation{
    position: relative;
    display: flex;
    justify-content: center;
    align-items: center;
    background: #fff;
    padding: 20px;
    transition: 0.5s;
    border-radius: 4px;
    overflow: hidden;
    box-shadow: 0 8px 15px rgba(0, 0, 0, .2);
}

.menu{
    margin: 0;
    padding: 0;
    width: 0;
    overflow: hidden;
    display: flex;
    transition: 0.5s;
}

.navigation input:checked ~ .menu{
    width: 400px;
}

.menu li{
    list-style: none;
    margin: 0 10px;
}

.menu li a{
    text-decoration: none;
    color: #666;
    text-transform: uppercase;
    font-weight: 600;
    transition: 0.5s;
}

.menu li a:hover{
    color: #42a8f9;
}

.navigation input{
    width: 40px;
    height: 40px;
    cursor: pointer;
    opacity: 0;
}

.navigation span{
    position: absolute;
    left: 26px;
    width: 32px;
    height: 4px;
    background: #666;
    pointer-events: none;
    transition: 0.5s;
}

.navigation input:checked ~ span{/*(alt + 126)*/
    background: #f974a1;
}

.navigation span:nth-child(2){
    transform: translateY(-8px);
}

.navigation input:checked ~ span:nth-child(2){
    transform: translateY(0) rotate(45deg);
}

.navigation span:nth-child(3){
    transform: translateY(8px);
}

.navigation input:checked ~ span:nth-child(3){
    transform: translateY(0) rotate(-45deg);
}