ss="btn__icon-container">
  <i class="fas fa-expand"></i>
  </span>

</button>



<button class="btn btn-sm nav-link pst-navbar-icon theme-switch-button pst-js-only" aria-label="Color mode" data-bs-title="Color mode"  data-bs-placement="bottom" data-bs-toggle="tooltip">
  <i class="theme-switch fa-solid fa-sun                fa-lg" data-mode="light" title="Light"></i>
  <i class="theme-switch fa-solid fa-moon               fa-lg" data-mode="dark"  title="Dark"></i>
  <i class="theme-switch fa-solid fa-circl