body {
    font-family: 'Arial', sans-serif;
    background-color: #f0f4f8;
    color: #333;
    line-height: 1.6;
    margin: 0;
    padding: 0 2em;
  }
  h2, h3, h4, h5, h6 {
    color: #2c3e50;
  }
  a {
    color: #3498db;
  }
  .block {
    background-color: #ecf0f1;
    padding: 1em;
    margin: 1em 0;
    border-left: 5px solid #3498db;
    border-radius: 4px;
  }
  .example {
    background-color: #dff9fb;
    padding: 1em;
    margin: 1em 0;
    border-left: 5px solid #6ab04c;
    border-radius: 4px;
  }
  .exercise {
    background-color: #f0f0f0; /* Couleur de fond gris clair */
    padding: 1em;
    margin: 1em 0;
    border-left: 5px solid #f0932b;
    border-radius: 4px;
  }
  .case-study {
    background-color: #f6e58d;
    padding: 1em;
    margin: 1em 0;
    border-left: 5px solid #f0932b;
    border-radius: 4px;
  }
  .tips{
    background-color: #eaefcf;
    padding: 1em;
    margin: 1em 0;
    border-left: 5px solid #c1e10b;
    border-radius: 4px;
  }
  .quiz {
    background-color: #eaf2f8;
    padding: 1em;
    margin: 1em 0;
    border-left: 5px solid #9b59b6;
    border-radius: 4px;
  }
  .quiz h3 {
    margin-top: 0;
  }
  .quiz button {
    background-color: #3498db;
    color: #fff;
    border: none;
    padding: 0.5em;
    margin-top: 0.5em;
    cursor: pointer;
    border-radius: 4px;
  }
  .quiz button:hover {
    background-color: #2980b9;
  }
  .quiz .answer {
    display: none;
    margin-top: 0.5em;
  }
  .animated-neuron {
    animation: pulse 2s infinite;
  }
  @keyframes pulse {
    0% { fill: #9b59b6; }
    50% { fill: #3498db; }
    100% { fill: #9b59b6; }
  }
  .table-of-contents ul {
    list-style-type: none;
    padding: 0;
  }
  .table-of-contents li {
    margin: 0.5em 0;
  }
  .table-of-contents a {
    text-decoration: none;
    color: #3498db;
    font-weight: bold;
  }
  .table-of-contents a:hover {
    text-decoration: underline;
  }
  .section {
    margin-top: 2em;
  }