* {
  box-sizing: border-box;
}

a {
  text-decoration: none;
  font-weight: bold;  
}

body {
  background: black;
  margin: 0;
  padding: 0;
  min-width: 340px;
}

div.centerwrapper {
  max-width: 1280px;
  margin: auto;
}

header {
  clear: both;
  padding-left: 1em;
}

header * {
  vertical-align: middle;
  color: rgb(20, 20, 140);
}

header h1 {
  margin: 0;
  padding: 0;
  font: 30px sans-serif;
  font-weight: bold;
}

header img {
  max-width: 20%;
}

img {
  max-width: 90%;
}

nav {
  background: rgb(20,20,90);
  font: 14px sans-serif;
  display: flex;
  flex-direction: row;
  padding-left: 1em;
}

nav a {
  text-decoration: none;
  color: rgb(200, 200, 255);
  padding: 8px;
  border: 1px solid rgb(100, 100, 155);
}

nav a.current {
  background: rgb(40, 40, 140);
}

nav a:hover {
  background: rgb(60, 60, 160);
  color: rgb(255, 250, 225);
}

nav + nav {
  margin-top: 8px;
}

nav button {
  display: none;
}

nav button {
  border: 1px solid rgb(100, 100, 155);
  color: rgb(200, 200, 255);
  padding: 8px;
  background: rgb(20,20,90);
}

section {
  background: rgb(150, 150, 205);
  margin: 1em;
  padding: 0.5em 1em;
  color: rgb(20,20,90);
}

section h2 {
  font: 22px serif;
  font-weight: bold;
  text-decoration: none;
  padding: 0;
  padding-left: 0.3em;
  margin: 0;
  margin-top: 0.3em;
  margin-bottom: 0.4em;
  border-bottom: 1px solid rgb(50, 50, 150);
}

section h3 {
  font: 18px serif;
  font-weight: bold;
  text-decoration: none;
  padding: 0;
  padding-left: 0.3em;
  margin: 0;
  margin-top: 0.3em;
  margin-bottom: 0.4em;
  margin-left: 0.6em;
  border-bottom: 1px dotted rgb(50, 50, 150);
}

section p {
  font: 14px sans-serif;
  padding: 0;
  margin: 0;
  margin-top: 0.4em;
  margin-bottom: 0.9em;
}

footer {
  background: rgb(20,20,90);
  color: rgb(100, 100, 200);
  font: 11px sans-serif;
  padding: 0.2em;
  clear: both;
}


@media screen and (max-width: 500px) {
  nav {
    flex-direction: column;
    padding-left: 0em;
  }
  
  nav button {
    display: initial;
  }
  
  nav.opened button:after {
    content: " \25BC";
  }
  
  nav button:after {
    content: " \25BA";
  }
  
  nav a {
    display: none;
  }
  
  nav.opened a {
    display: initial;
  }

}