@media only screen and (orientation: portrait) and (max-width: 600px) {
    #book {
      grid-template-rows: 71px auto 40px;
      grid-template-columns: 10px auto;
    }

    .content {
      grid-template-rows: auto;
      grid-template-columns: 1fr;
    }

    .titel {
      grid-column: 1;
    }

    #logo {
      width: 200px;
      height: 200px;
    }
    
    #page-cover,
    #page-current,
    #page-previous,
    #page-next {
      grid-column: 2;
      grid-row: 2;
    }

    #page-cover {
      padding-top: 80px;
    }
    
    #navBar {
      grid-column: 2;
      grid-row: 1;
      padding-left: 20px;
      grid-template-columns: auto 1fr auto;
    } nav {
      grid-row: 1;
      margin: auto 6px 0px auto;
      height: 50px;
      width: 50px;
      border-bottom: none;
    } nav.active {
      width: 50px;
      height: 70px;
    }

    #homeBtn {
      margin-top: 18px;
    } .navSymbol {
      width: 40px;
      height: 40px;
      margin: 2px auto auto auto;
    }
}