@media screen and (max-width: 768px) {
  nav {
    display: none;
  }

  header {
    padding: 15px 0;
  }

  .boutonBurger {
    display: block;
  }

  .container {
    width: 95%;
  }

  .card {
    margin: 10px 0;
    padding: 15px;
  }

  .card h3 {
    font-size: 1.1em;
  }

  .card p {
    font-size: 1em;
  }

  header img {
    margin-bottom: 0px;
    margin-top: 0px;
  }
}