* {
    box-sizing: border-box;
}

body {
    margin: 0;
    padding: 0;
    font-family: 'Bad Script', cursive;
    color: #ffff;
    font-size: 50px;


}

.slider {
    display: flex;
    justify-content: center;
    align-items: center;


}

.item {

    display: flex;
    flex-basis: 30%;
    justify-content: center;
    align-items: center;
    height: 100vh;
    transition: all 0.4s;


}





.item-1 {
    background: url(https://cdn.pixabay.com/photo/2016/01/19/17/08/vintage-1149558_960_720.jpg) no-repeat center center;
    background-size: cover;

}

.item-2 {
    background: url(https://cdn.pixabay.com/photo/2015/11/19/21/10/knowledge-1052010_960_720.jpg) no-repeat center center;
    background-size: cover;
}

.item-3 {
    background: url(https://cdn.pixabay.com/photo/2013/03/02/02/41/city-89197_960_720.jpg) no-repeat center center;
    background-size: cover;
}

.item-4 {
    background: url(https://cdn.pixabay.com/photo/2014/09/05/18/32/old-books-436498_960_720.jpg) no-repeat center center;
    background-size: cover;

}

.item-1:hover {
    flex-basis: 50%;
}

.item-2:hover {
    flex-basis: 50%;

}

.item-3:hover {
    flex-basis: 50%;
}

.item-4:hover {
    flex-basis: 50%;
}

span {
    text-shadow: 0px 0px 10px;
}

@media (max-width: 640px) {
    .slider {
        flex-flow: column;
        height: 100vh;
    }

    .item {
        width: 100%;
        height: 25vh;
    }

    .item:hover {
        flex-grow: 30%;
    }
}