mozilla-release/layout/reftests/forms/input/number/number-min-height-1.html

<!DOCTYPE html>
<html>
  <head>
    <style>

input {
  border: 3px solid black;
  padding: 4px;
  width: 300px;
  min-height: 100px;
  box-sizing: content-box;
  /* hide the spin buttons: */
  -moz-appearance: textfield;
}

* > input[type=number] {
  /* get rid of background gradient for Firefox OS */
  background-color: transparent ! important;
}

    </style>
  </head>
  <body>
    <input type="number">
  </body>
</html>