@media print, screen and (min-width: 64em) {
  /* Bloc du niveau 3 : largeur fixe, fond blanc plein, coins arrondis */
  .o-header__nav .menu .sub-menu .sub-menu {
    position: absolute;
    top: 0;
    left: 100%;
    width: 260px;
    padding: 12px 0;
    margin: 0;
    background-color: #ffffff !important;
    box-shadow: 0 10px 10px 0 rgba(0, 0, 0, .15);
    border-radius: 3px;
    z-index: 11;
    box-sizing: border-box;
  }

  .o-header__nav .menu .sub-menu .sub-menu .menu-item {
    display: block;
    width: 100%;
    margin: 0 !important;
    padding: 8px 20px;
    background-color: #ffffff;
    box-sizing: border-box;
  }

  .o-header__nav .menu .sub-menu .sub-menu .menu-item a {
    display: block;
    width: 100%;
  }

  /* Flèche indiquant qu'un élément de niveau 2 a un niveau 3 à déplier */
  .o-header__nav .sub-menu > .menu-item-has-children > a {
    position: relative;
    padding-right: 20px;
  }

  .o-header__nav .sub-menu > .menu-item-has-children > a::after {
    content: "›";
    position: absolute;
    right: 0;
    top: 50%;
    font-weight: bold;
    transform: translateY(-50%) rotate(0deg);
    transition: transform .2s ease;
  }

  .o-header__nav .sub-menu > .menu-item-has-children:not(.collapsed) > a::after {
    transform: translateY(-50%) rotate(90deg);
  }
}