.slide-wrap {
    margin-bottom: 30px;
}

.slide-wrap .slide {
    display: none;
    position: relative;
    background-size: cover;
    background-repeat: no-repeat;
    background-position: center center;
    vertical-align: middle;
}

.slide-wrap .slide:before {
    content: "";
    display: block;
    padding-bottom: 70%;
}