header {
  display: none;
  position: fixed;
  width: 25vw;
  min-width: 250px;
  min-height: 100vh;
  float: left;
}
header .nav_content {
  position: relative;
  left: 0;
  top: 10vh;
  width: 80%;
  margin: 0 auto;
  color: #9F2F1C;
  text-align: center;
}
header .nav_content img {
  width: 80%;
  max-height: 250px;
}
header .nav_content a {
  text-transform: uppercase;
  font-size: 1.3em;
  line-height: 30px;
  display: block;
  color: #9F2F1C;
}
header .nav_content a:hover{
    font-weight: 800;
}
header .nav_content a.active{
  font-weight: 800;
}
.content {
  position: absolute;
  left: 12.5vw;
  right: 12.5vw;
  min-width: 400px;
  margin: 20px 4% 20px 4%;
}
.content section {
  //font-size: 1.2em;
  line-height: 25px;
  text-align: left;
}
ul, ol {
  font-size: 1em;
}
.content section a {
  text-decoration: underline;
}
.content section a:hover {
  color: #999!important;
}
.content section .chapter_image {
  width: 100%;
  height: 300px;
  background-size: cover;
  background-position: center;
  transition: background-size 2s ease;
}
.content section .content_element, .content section .content_element video {
  height: 350px;
  overflow: scroll;
}
footer {
  margin-top: 20px;
  text-align: center;
  padding: 5px;
  color: white;
}
footer > a {
  font-size: 1.1em;
  color: black;
}
footer > a:after {
  content: ' -'
}
footer > a:last-child:after {
  content: ''
}
.content section p.spalten {
  -webkit-column-count: 3;
  -moz-column-count: 3;
  column-count: 3;
}
@media all and (max-width: 1200px) {
  header .nav_content {
    width: 90%;
  }
  header .nav_content a {
    font-size: 1.0em;
  }
  header .nav_content h1 {
    font-size: 1.5em;
  }
  .content section p.spalten {
    -webkit-column-count: 2;
    -moz-column-count: 2;
    column-count: 2;
  }
}
@media all and (max-width: 1000px) {
  .content {
    left: 250px;
    margin: 10px 4% 10px 4%;
  }
  .content section p.spalten {
    -webkit-column-count: 1;
    -moz-column-count: 1;
    column-count: 1;
  }
}
#triangle {
    width: 70%;
    padding-left: 15%;
}