.slide {
    /*styling for all slides*/
    /*a dot is used to select all elements with a specified class*/
    /*display: none hides the slide*/
    display: none;
}

.slide.showing {
    /*styling for the slide that also has a "showing" class*/
    /*display: block shows the slide*/
    display: block;
}

#slider {
    /*makes the slider longer*/
    width: 300px;
}