#toc-container {
  h2 {
    display: inline-block;
  }

  input, input + span {
    margin-left: 1rem;
  }

  input {
    position: absolute;
    width: 50px;
    height: 20px;
    opacity: 0;
    margin-top: 10px;
  }

  input + span::before {
    content: '[hide]';
  }

  input:checked ~ ul {
    display: none;
  }

  input:checked + span::before {
    content: '[show]';
  }
}