.slider {
    z-index: 9;
    height: 300px;
    overflow: hidden;
    margin: 0 0 7px;
    position: relative;
}

.slider ul,
.slider li {
    padding: 0;
    margin: 0;
    list-style-type: none;
}
.slider ul {
    width: 9999px;
}
.slider ul li {
    list-style-type: none;
    float: left;
    height: 300px;
}

@media screen and (min-width: 768px) {
    .slider {
        width: 600px;
    }
    .slider ul li {
        width: 600px;
    }
}

.slider .nav {
    position: absolute;
    left: 15px;
    bottom: 12px;
    z-index: 99;
}
.slider .nav span {
    opacity: 0.7;
    background: #888;
    margin: 0 6px 0 0;
    width: 12px;
    height: 12px;
    border-radius: 6px;
    cursor: pointer;
    overflow: hidden;
    display: block;
    float: left;
    box-shadow: 0 1px 2px #000;
}
.slider .nav span.on {
    opacity: 1;
    background: #fff;
}