body {
  font-family: Microsoft JhengHei;
}

.generate {
  border: none;
  background: transparent;
  outline: none;
  overflow: none;
  cursor: pointer;
}

.number {
  text-shadow: 0 0 5px #bbb;
  font-size: 400px;
  width: 100%;
  min-height: 50%;
  overflow: auto;
  margin: auto;
  position: absolute;
  top: 0;
  left: 0;
  bottom: 0;
  right: 0;
}

.options {
  background-color: #555;
  border-radius: 20px;
  color: #efefef;
  padding: 5px 15px;
  position: absolute;
  cursor: pointer;
}

.options input {
  background-color: #efefef;
  padding: 5px;
  margin: 5px 5px;
}