body {
  font-family: sans-serif;
  padding: 20px;
}

input {
  padding: 5px;
}

li {
  margin: 8px 0;
}

button {
  margin-left: 10px;
}

.high {
  color: red;
}

.medium {
  color: orange;
}

.low {
  color: green;
}

.completed {
  text-decoration: line-through;
  opacity: 0.6;
}