.align-items-center {
  align-items: center !important;
}

.justify-content-center {
  justify-content: center !important;
}

.center {text-align:center}

.flex-container {
  display: flex;
  flex-wrap: wrap; 
  background-color: none;
  align-items: center;
  justify-content: center;
}

#display {
  /*border: solid 1px #ccc;
  padding: 20px;*/
  min-height: 20vh;
  color: black;
  font-size: 16px;
  padding-left: 10px;
  padding-right: 10px;
  border: 1px solid #003366;
  border-radius: 4px;
  background: white;
  outline: none;
}