.thumbnail-wrapper {
    margin-bottom:5px;
}

.thumbnail {
  position: relative;
  padding-top: 70%;
  overflow: hidden;
  
}

.thumbnail-centered {
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  transform: translate(50%, 50%);
}

.thumbnail-img {
    width:100%;
/*   max-width: 100%; */
/*   height: 박스의 height와 같아야 한다. */
  transform: translate(-50%, -50%);
}


.main_color {
  background-color: #0b3866;
}