*,
*::before,
*::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  height: 100vh;

  display: flex;
  align-items: center;
  justify-content: space-around;
  flex-direction: column;
}

header {
  font-size: 2rem;
}

button {
  font-size: 1rem;
  padding: 0.5rem;
}