.numpad {
  margin-top: 20px;
  margin-left: auto;
  margin-right: auto;
  height: 0px;
  overflow: hidden;
  transition: all 0.5s;
}

.numpad.open {
  height: 250px !important;
}

.numpad button {
  font-weight: bold;
  font-size: 140%;
  width: 100%;
}

.numpad .row {
  margin-bottom: 15px;
}

.numpad .row:last-of-type {
  margin-bottom: 0px;
}