html, body {
  height: 100%;
  margin: 0;
  background: #000;
  color: #fff;
}

#editor {
  border: 1px solid #555;
  padding: 10px;
  box-sizing: border-box;
  height: 100%;
  overflow: auto;
  background: #000;
  color: #fff;
}

input, button {
  background: #222;
  color: #fff;
  border: 1px solid #555;
}