#Kalk * {
  font-size: 16px;
}

#Kalk table {
  margin: 0 auto;
  border: solid 3px black;
  border-spacing: 3px;
  background-color: white;
}

#Kalk table td {
  border-spacing: 3px;
}

td.disp {
    display: flex;
    flex-direction: column;
}

input.display {
  width: 166px;
  text-align: right;
    align-self: center;
}

td.buttons {
  border-top: solid 1px black;
    padding: 10px;
}

input[type=button] {
  width: 40px;
  height: 30px;
}