body, ul, li, a {
    padding: 0;
    margin: 0;
    list-style: none;
    text-decoration: none;
    font-size: 0;
}

.wrapper {
    position: relative;
    width: 520px;
    height: 280px;
    margin: 150px auto;
    border: 5px solid #000;
    overflow: hidden;
}
.wrapper:hover .btn {
    display: block;
}
.img-box  {
    position: absolute;
    left: 0;
    width: 3120px;
    height: 280px;
}
.img-box li {
    display: inline-block;
}
/* btn */
.btn {
    position: absolute;
    top: 50%;
    display: none;
    width: 520px; 
}
.btn a {
    position: absolute;
    top: -22px;
    width: 15px;
    height: 24px;
    padding: 10px;
    font-size: 16px;
    line-height: 24px;
    background: rgba(0, 0, 0, .5);
    color: #fff;
}
.btn .prevBtn {
    left: 0;
}
.btn .nextBtn {
    right: 0;
}

/* order */
.order {
    position: absolute;
    bottom: 20px;
    width: 100%;
    text-align: center;
}
.order ul {
    display: inline-block;
    border-radius: 6px; 
    background: rgba(0, 0, 0, .5);
}
.order ul li {
    display: inline-block;
    width: 10px;
    height: 10px;
    margin: 2px;
    border-radius: 50%;
    background: #fff;
    cursor: pointer;
}
.order ul .active {
    background: #ff6700;
}