body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Oxygen,
    Ubuntu, Cantarell, "Open Sans", "Helvetica Neue", sans-serif;
}
center {
  margin-top: 20vh;
}
time {
  font-size: 18vw;
  text-align: center;
}


button{
  background: steelblue;
  padding: 5px 10px;
  font-size: 1.1rem;
  outline: none;
  border: none;
  color: #fff;
  border-radius: 5px;
  cursor: pointer;
  margin: 30px;
}