.jdbigdiv {
    width: 583px;
    overflow: hidden;
}

.jdbigimg {
    width: 520px;
    height: 390px;
    box-sizing: border-box;
    border: 2px solid rgb(238, 238, 238);
    overflow: hidden;
    margin-bottom: 15px;
    float: left;
}

.jdsmallimg {
    float: left;
    width: 52px;
    height: 389px;
}

.jdsmallimg img {
    width: 50px;
    height: 50px;
}

.jdsmallimg ul {
    display: flex;
    flex-wrap: wrap;
    align-content: space-between;
    height: 389px;
}

.jdsmallimg li {
    cursor: pointer;
    border: 1px solid transparent;
}

.jdsmallimg li img {
    display: block;
}

.jdsmallimg li.active {
    border: 1px solid red;
}