html, body {
  height: 100%;
  margin: 0;
  overflow: hidden;
}

body {
  font-family: "Segoe UI", sans-serif;
  cursor: pointer;
  background: #fafafa;
}

.container {
  display: flex;
  justify-content: center;
  align-items: center;
  height: 100%;
  flex-direction: column;
}

#score, #highscore {
  position: absolute;
  top: 20px;
  right: 20px;
  font-size: 1.5em;
  font-weight: 900;
  color: #111;
}

#highscore {
  top: 60px;
  font-size: 1.2em;
  color: #444;
}

#introduction {
  width: 220px;
  position: absolute;
  font-weight: 600;
  font-size: 0.9em;
  text-align: center;
  transition: opacity 2s;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
}
#introduction a {
  text-decoration: none;
  color: #e84656;
  font-family: cursive;
  font-size: 18px;
}

button {
  position: absolute;
  border-radius: 12px;
  padding: 12px 18px;
  font-weight: 700;
  border: none;
  cursor: pointer;
  font-size: 1.1em;
}

#restart {
  bottom: 80px;
  background: royalblue;
  color: white;
  display: none;
}

#pause {
  bottom: 20px;
  background: crimson;
  color: white;
}