.example {
    text-align: center;
    margin: 100px;
}

.slider {
    display: inline-block;
}

.page {
    width: 300px;
    height: 100px;  
    border-radius: 2px;
    box-shadow: inset 0 0 6px 0 rgba(0,0,0,0.4);
    background-repeat: no-repeat;
    background-size: cover;
}

.page:nth-child(1) {
    background-image: url('http://www.lorempixum.com/300/100/?1');
}
.page:nth-child(2) {
    background-image: url('http://www.lorempixum.com/300/100/?2');
}
.page:nth-child(3) {
    background-image: url('http://www.lorempixum.com/300/100/?3');
}
.page:nth-child(4) {
    background-image: url('http://www.lorempixum.com/300/100/?4');
}