* {
  box-sizing: border-box;
}

html, body {
  width: 100%;
  height: 100%;
}

body {
  margin: 0;
  background: #222;
}

p {
  padding: 1em;
  font-family: monospace;
  font-size: 2em;
}

button {
  margin: auto;
  text-align: center;
  display: block;
  width: 250px;
  height: 70px;
  background: orange;
  border: 0;
  cursor: pointer;
  position: absolute;
  left: 0;
  right: 0;
  border-radius: 3px;
  font-family: monospace;
  font-size: 2em;
}

article {
  width: 80%;
  margin: auto;
}