*, *:before, *:after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  /*margin-left: calc(100vw - 100%);*/
  overflow-y: scroll;
}

body {
  font: 1rem sans-serif;
  color: #555;
}

ul.topnav {
  list-style-type: none;
  margin: 0;
  padding: 0;
  position: fixed; /* Set the navbar to fixed position */
  width: 100%; /* Full width */
  background-color: #fff;
}

ul.topnav li {float: left;}

ul.topnav li a {
  display: block;
  text-align: center;
  padding: 14px 16px;
  text-decoration: none;
  color: #555;
}

ul.topnav li.right {float: right;}

ul.topnav li a:hover {background-color: #eee;}

a {
  color: orange;
  text-decoration: none;
}

.banner {
  height: 450px;
  background: transparent url('banner.svg') 0 60px no-repeat fixed;
  padding: 7em 0;
}

h1 {font-size: 200%;}

h1, h2 {
  padding: 1em 0;
  font-weight: 400;
  text-align: center;
}

p, dl, table {
  margin: auto;
  line-height: 1.5;
  max-width: 80ch;
}

p.center {text-align: center;}

dd {margin-left: 2ch;}

td {padding: 1ch;}

footer {
  margin-top: 4ch;
  text-align: center;
  font-size: 85%;
}

.menu-mobile {display: none;}

@media screen and (max-width: 600px) {

  p, dl {margin-left: 2ch;}

  .menu {display: none;}
  .menu-mobile {display: block;}

  ul.topnav li {float: none;}
  ul.topnav {position: static;}

  details > summary {list-style: none;}
}