.custom-image-hover img {
  transition: all 0.3s ease;
  border-radius: 0;
  border: 2px solid transparent;
}

.custom-image-hover:hover img {
  border: 3px solid #1B4482;
}

Buttondesign + Hover
.custom-button {
  background-color: #B5E8EF;
  color: #1B4482;
  padding: 4px 8px;
  text-decoration: none;
  border-radius: 100px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  transition: all 0.3s ease;
  border: 3px solid transparent;
  text-align: center;
  gap: 8px;
  box-sizing: border-box;
}

.custom-button i {
  color: inherit;
  font-size: 1em;
  line-height: 1;
}

.custom-button:hover {
  background-color: #B5E8EF;
  color: #1B4482;
  box-shadow: 0 0 0 3px #1B4482;
  border-radius: 100px; /* <- HIER das dazu */
}

.custom-button:hover i {
  color: inherit;
}