.flag-wrapper {
  width: 30px;
  display: inline-block;
  position: relative;
  height:20px;
  vertical-align: middle;
  margin-right:15px;
}
.flag-wrapper:after {
  padding-top: 75%;
  /* ratio */
  display: block;
  content: '';
}
.flag-wrapper .flag {
  position: absolute;
  top: 0;
  bottom: 0;
  right: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background-size: cover;
}