button {
  outline: none;
  box-shadow: 0px 0px 1px black;
  cursor: pointer;
}
button:hover {
  background-color: yellow;
}
button[value="on"] {
  background-color: gray;
  cursor: not-allowed;
}
button[value="off"] {
  background-color: lightgray;
}
a {
  color: black;
  text-decoration: none;
}
input[type="number"] {
  appearance: none;
}
input[type="number"]::-webkit-inner-spin-button,
input[type="number"]::-webkit-outer-spin-button {
  -webkit-appearance: none;
  -moz-appearance: textfield;
}