html, body {
  min-height: 100vh;
  margin: 0;
}

body {
  background-color: #458b74;
  font-size: 18px;
}

button {
  font-size: 24px;
}

main {
  width: 70%;
  background-color: #bcee68;
  border: black solid 5px;
  padding: 5px;
  margin: auto;
  min-height: 100vh;
}

input[type="number"] {
    max-width: 100px;
}