html, body {
  font-family: sans-serif;
}
#nav {
  padding: 0;
  margin: 0.5em;
  top: 0;
  height: 2em;
}
button, a.button {
  color: black;
  text-decoration: none;
  background-color: #59b061;
  border: 1px solid #59b061;
  border-radius: 10px;
  padding: 0.5em 1em 0.5em 1em;
  font-weight: bold;
  cursor: pointer;
  margin-right: 1em;
}
button:hover, a.button:hover {
  background-color: #59b072;
}
button:active, a.button:active {
  position:relative;
  top:1px;
}
button.display {
  background-color: white;
  cursor: default;
}