@media(max-width:999px) {
    #slider {
        max-width: 320px;
    }
    
    #slider ul li {
        max-width: 250px;
        max-height: 150px;
    }
}

#slider {
    position: relative;
    overflow: hidden;
    margin: 20px auto 20px auto;
    border-radius: 4px;
}

#slider ul {
    position: relative;
    margin: 0;
    padding: 0;
    height: 200px;
    list-style: none;
}

#slider ul li {
    position: relative;
    display: block;
    float: left;
    margin: 0;
    padding: 0;
    width: 500px;
    height: 300px;
    background: transparent;
    text-align: center;
    line-height: 300px;
}

#slider a img {
    height: 100%;
}

a.control_prev,
a.control_next {
    position: absolute;
    top: 40%;
    z-index: 999;
    display: block;
    padding: 4% 3%;
    width: auto;
    height: auto;
    background: lightsalmon;
    color: black;
    text-decoration: none;
    font-weight: 600;
    font-size: 18px;
    opacity: 0.8;
    cursor: pointer;
}

a.control_prev:hover,
a.control_next:hover {
    opacity: 1;
    -webkit-animation: all 0.2s ease;
    animation: all 0.2 ease;
}

a.control_prev {
    border-radius: 2px 2px 2px 2px;
}

a.control_next {
    right: 0;
    border-radius: 2px 2px 2px 2px;
}