body {
  
}
div.header {
    padding: 20px 10px;
}
.nav>li>a {
    position: relative;
    display: block;
    padding: 6px 12px;
    font-size: large;
}
nav.sidebar {
    border-left: black 1px dotted;
}

#btn-back-to-top {
    position: fixed;
    bottom: 20px;
    right: 20px;
    display: none;
  }
  img.reverse {
    -webkit-transform: scaleX(-1);
    transform: scaleX(-1);
  }
  h2 {
    border-top: 3px black solid;
    border-left: 2px darkgray solid;
    border-right: 2px darkgray solid;
    border-bottom: 2px darkgray solid;
    padding: 5px ;
    background-color: #EEEEEE;
    margin-bottom: 20px;
  }