.mbr-test-component {
  background-color: gainsboro;
  text-align: center;
}

.social-feed-container {
  z-index: 3;
  max-width: 600px;
  margin: 0 auto;
  position: relative;
}
.mbr-social-feed{
    position: relative;
    background-size:cover;
    padding-top: 20px;
    padding-bottom:20px;
}
.social-feed-element iframe {
    width: 100%;
    height: 300px;
    text-align: center;
    margin: 0 auto;
    display: block;
}