.encryption-ecb figure {
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  cursor: pointer;
}
.encryption-ecb figure img {
  display: none;
  max-width: 400px;
  max-height: 400px;
}
.encryption-ecb figure img.visible {
  display: initial;
}
.encryption-ecb figure figcaption {
  padding: 10px;
}