nav {
  border-color: darkcyan;
}
.link-list {
  display: flex;
  justify-content: flex-start;
  float: left;
  width: 100%;
  margin: 0;
}
.link-item {
  /*border: 1px solid white;*/
  padding: 0.5rem;
  width: 8rem;
  height: 6rem;
}
.link-item iframe {
  width: 100%;
  height: 100%;
}