html,
body {
  margin: 0;
  padding: 0;
}

canvas {
  display: block;
}

button {
  width: 2em;
  height: 2em;
  border-radius: 10%;
  background-color: gainsboro;
}

button:hover {
  background-color: ghostwhite;
}

#instr {
  position: absolute;
  bottom: 20px;
  left: 20px;
  font-family: sans-serif;

}