html {
  background: #f1f1f1;
  font-size: 100%;
  font-family: sans-serif;
  line-height: 1.5rem;
}

body {
  background: white;
  max-width: 48rem;
  margin: 3rem auto;
  padding: 1.5rem 1.5rem 1px;
  box-shadow: 0 1px 3px rgba(0,0,0,.15);
  text-align: center; 
}

p {
  margin: 0 0 1.5rem;
}

.btn { 
  display: inline-block;
  padding: .75rem 1.5rem;
  background: black;
  color: white;
  text-decoration: none;
}

#timer {
  font-weight: bold;
}