@media only screen and (max-width: 991px) {

  /* Trigger mobile menu at 992px */
  .menu-toggle-button,
  .menu-toggle-state  {
    display: inline-block;
  }

  .menu-toggle-state:not(:checked) ~ .menu {
    display: none;
  }

  .block-system-main-menu {
    width: 50%;
    max-width: 210px;
  }

  /* Align Menu Toggle */
  .block-system-main-menu .block-content {
    text-align: right;
    width: 100%;
  }

  .block-system-main-menu .block-content .menu-toggle-button {
    margin-right: 0;
    margin-left: auto;
  }

  .block-system-main-menu .block-content ul.menu {
    text-align: left;
    width: 100%;
    background-color: var(--lighter-grey-colour);
    margin-top: 10px;
  }

  .block-system-main-menu .block-content ul.menu:before {
    content: ' ';
    position: absolute;
    top: -0.8em;
    right: 0.8em;
    border-width: 8px;
    border-style: dashed dashed solid dashed;
    border-color: transparent transparent var(--lighter-grey-colour) transparent;
    background: transparent;
  }

  .block-system-main-menu .block-content ul.menu li {
    padding: 0;
  }

  .block-system-main-menu .block-content ul.menu li a {
    padding: 8px 15px;
  }

  .block-system-main-menu .block-content ul.menu li.first a {
    padding-top: 15px;
  }

  .block-system-main-menu .block-content ul.menu li.last a {
    padding-bottom: 15px;
  }

  .block-system-main-menu .block-content ul.menu li a:hover,
  .block-system-main-menu .block-content ul.menu li a:focus {
    background-color: var(--light-grey-colour);
  }

  .block-system-main-menu .block-content ul.menu li.expanded ul {
    background-color: #ddd;
    padding-left: var(--gutter-width);
  }

}