@media only screen and (max-width: 768px) {
  body {
    font-size: 13px;
  }
  .page-content {
    flex-direction: column;
  }
  .page-sidebar {
    width: 100%;
  }
  #nav a {
    display: block;
    padding: 0.3rem 0;
  }
  table {
    font-size: 0.8rem;
  }
  img {
    width: 100%;
  }
  .card {
    padding: 0.75rem;
  }
  .btn {
    width: 100%;
    text-align: center;
    box-sizing: border-box;
  }
}