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

html {
  font-size: 62.5%;
}

body {
  background: #2b292e;
  color: #fafafa;
  font-family: Helvetica, Arial, sans-serif;
  font-size: 1.6rem;
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 100vh;
}

span {
  border-bottom: 1px solid #534f59;
  display: inline-block;
  font-size: 2rem;
  height: 2.4rem;
  line-height: 2.4rem;
  margin: 0 0.25rem;
  text-align: center;
  text-transform: uppercase;
  width: 2.4rem;
}

p {
  font-weight: 300;
  margin-bottom: 0.8rem;
}

.puzzle {
  display: flex;
  margin-bottom: 4.8rem;
}

.button {
  background: #7044a0;
  border: none;
  border-bottom: 2px solid #603a88;
  cursor: pointer;
  color: white;
  font-size: 1.4rem;
  font-weight: 300;
  padding: 0.8rem;
  transition: background 0.3s ease, color 0.3s ease;
}

.button:hover {
  background: #5f3a87;
}