html,
body {
  position: relative;
  width: 100vw;
  height: 100vh;
  padding: 0;
  margin: 0;
}

body {
  background: #0193ff;
}

canvas
{
  position: fixed;
  left:0;
  bottom: 0;
  right: 0;
  z-index: -1;
}

button {
  background-color: #4caf50; /* Green */
  border: none;
  color: white;
  padding: 15px 32px;
  text-align: center;
  text-decoration: none;
  display: inline-block;
  font-size: 16px;
  border-radius: 20px;
}

button.neutral {
  background-color: #ccc;
}