.image-caption {
    position: absolute;
    bottom: 20px;
    left: 0;
    right: 0;
    text-align: center;
    color: #FFFFFF;
    font-weight: 700;
    font-size: 18px;
    text-transform: uppercase;
    z-index: 2;
}

.vc_column_container {
    position: relative;
}

.vc_single_image-wrapper img {
    width: 100%;
    height: auto;
}