app/assets/stylesheets/application.css

gistfile1.css

.media-grid {
  width: 100%;
}

.media-grid > li {
  float: left;
  display: block;
  margin-right: 20px;
  margin-bottom: 20px;
  width: 255px;
  height: 300px;
  position: relative;
}

.media-grid img {
  width: 260px;
  margin: auto;
  max-height: 260px;
}

.media-grid .controls {
  position: absolute;
  bottom: 0;
  right: 0;
  padding: 10px;
  border-top: 1px solid #eee;
}

.media-grid .controls li {
  float: right;
  margin-left: 10px;
  list-style: none;
}