@media (max-width: 991px) {
  .offcanvas-collapse {
    position: fixed;
    top: 60px;
    /* Height of navbar */
    bottom: 0;
    right: 0;
    width: 100%;
    padding: 0;
    overflow-y: auto;
    visibility: hidden;
    background-color: rgba(0, 0, 0, .5);
    transition-timing-function: ease-in-out;
    transition-duration: .3s;
    transition-property: all;
  }

  .offcanvas-collapse.open {
    visibility: visible;
  }
}