@media only screen and (min-width:991px) {
  #header {
    width: 100px;
    position: fixed;
    left: 0;
    top: 0;
    height: 100vh;
    z-index: 99999 !important;
    display: flex;
    flex-direction: column;
    background-color: #fff; /* Change color as needed */
    box-shadow: 2px 0 8px rgba(0,0,0,0.06);
  }
  .header-nav-item {
    margin-bottom: 5px;
    padding: 10px;
    /* Style menu items */
  }
}