body {
  font-family: Arial, sans-serif;
}

ul {
  list-style: none;
  padding: 0;
}

li {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin: 8px 0;
}

li span {
  cursor: pointer;
}

.completed {
  text-decoration: line-through;
  color: gray;
}

button {
  margin-left: 10px;
  cursor: pointer;
}