html, body {
    margin: 0;
    padding: 0;
    width: 100%;
    height: 100%;
}

div {
    position: absolute;
    top: 0;
    width: 25%;
    height: 100%;
    background-position: center center;
    background-repeat: no-repeat;
    text-indent: -999em;
}

#summer {
    right: 0;
    background-color: #80c0ff;
    background-image: url(summer-vertical.png);
}

#autumn {
    right: 25%;
    background-color: #c00000;
    background-image: url(autumn-vertical.png);
}

#winter {
    right: 50%;
    background-color: #c0c0c0;
    background-image: url(winter-vertical.png);
}

#spring {
    right: 75%;
    background-color: #ffa0e0;
    background-image: url(spring-vertical.png);
}