Template:Message.css

.message {
  padding-left: 1rem;
  padding-right: 1rem;
 
  margin-top: 1rem;
  margin-bottom: 1rem;

  border-width: 1px;
  border-style: solid;
  border-radius: 0.5rem;
}

.message-info {
  border-color: rgb(0, 0, 255);
  background: rgba(0, 0, 255, 0.15)
}

.message-warning {
  border-color: rgb(255, 255, 0);
  background: rgba(255, 255, 0, 0.15)
}

.message-danger {
  border-color: rgb(255, 0, 0);
  background: rgba(255, 0, 0, 0.15)
}

.message-success {
  border-color: rgb(0, 255, 0);
  background: rgba(0, 255, 0, 0.15)
}