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

html {
  font-family: monospace;
}

html,
body {
  height: 100%;
  background-color: rgb(25, 150, 50);
}

header {
  padding: 2rem;
  background-color: lightgray;
  display: block;
  text-align: center;
}

input {
  margin: 1rem 1rem;
}

input#red {
  accent-color: red;
}

input#green {
  accent-color: green;
}

input#blue {
  accent-color: blue;
}

#color-output,
button {
  font-family: monospace;
  font-weight: bold;
  font-size: 1.5rem;
}

button {
  border-radius: 0.5rem;
  margin-top: 1rem;
}