.img-small {
  width: 40%;
}

.img-centered {
  display: block;
  margin-left: auto;
  margin-right: auto;
  max-width: 60%;
}

.video-container {
  position: relative;
  padding-bottom: 56.25%; /* 16:9 Aspect Ratio */
  height: 0;
  overflow: hidden;
  max-width: 100%;
}

.video-container iframe {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
}