ul {
  padding: 0;
}

li {
  list-style-type: none;
  color: darkred;
  margin: 0.5em 0;
}

li::before {
  content: "❌";
  margin-right: 0.5em;
}

li[correct] {
  color: darkgreen;
}

li[correct]::before {
  content: "✔️";
}