Royuwaay:Infobox/styles.css

.infobox caption {
  background: #415DCE;
  border-left: 1px solid #AAA;
  border-top: 1px solid #AAA;
  border-right: 1px solid #AAA;
  padding: 8px;
  margin-left: auto;
  font-weight: bolder;
  text-align: center;
  color: #FFF;
  font-size: 160%;
}