@font-face{
  font-family: 'Open Sans';
  font-style: normal;
  font-weight: 400;
  src: local('Open Sans'), local('OpenSans'), url(https://www.dennis-brendel.de/fonts/OpenSans.woff2) format('woff2');
}
@font-face{
  font-family: 'Open Sans';
  font-style: normal;
  font-weight: 700;
  src: local('Open Sans Bold'), local('OpenSans-Bold'), url(https://www.dennis-brendel.de/fonts/OpenSans-Bold.woff2) format('woff2');
}
body {
  margin: 0;
  color: #333;
  font-family: 'Open Sans', 'Liberation Sans', Calibri, 'sans serif', 'DejaVu Sans';
}
section, article, aside, footer, header, nav {
  display: block;
}
blockquote {
  text-align: center;
}
a {
  text-decoration: none;
  color: #333;
  transition: 0.3s ease;
}
a:hover {
  color: #005800;
}

nav > ul {
  padding-left: 0px;
  margin-top: 1em;
  list-style-type: none;
}
nav > ul > li > a.current_page {
  font-weight: bold;
}
img {
  max-width: 100%;
  width: 100%;
}

img.langFlag {
  max-width: 2em;
}

#wrapper {
  margin: 0;
  padding: 0;
  display: flex;
  flex-flow: row;
  height: 100vh;
}
#wrapper > nav {
  background-color: #f5f5f5;
  padding-left: 1em;
  padding-right: 1em;
  padding-top: 1em;
  flex: 1 0 12em;
}
#wrapper > main {
  padding-left: 1em;
  padding-right: 1em;
  box-shadow: -6px 0 6px rgba(213,213,213,0.66);
  flex: 1 1 auto;
  overflow: auto;
}
main > h1 {
  text-align: center;
}
main > .columns {
  display: flex;
  flex-flow: row;
  flex-wrap: wrap;
  justify-content: space-between;
}
main          > .columns > .column > h2,
main.threecol > .columns > .column > p:nth-of-type(1) {
  flex: 1 1 auto;
  text-align: center;
}
main.twocol     > .columns > .column { flex: 0 1 calc(50% - 1em); }
main.threecol   > .columns > .column { flex: 0 1 calc(33% - 1em); }

@media ( max-width: 70em ) {
  main.threecol > .columns > .column { flex: 0 1 calc(50% - 1em); }
}
@media ( max-width: 50em ) {
  #wrapper > nav {
    min-height: 0px;
    font-size: 1.2em;
    flex: 1 0 9em;
  }
  #wrapper > main {
    overflow: inherit;
  }
  #wrapper {
    flex-direction: column;
    min-height: 0px;
  }
  main          > .columns > .column, 
  main.twocol   > .columns > .column, 
  main.threecol > .columns > .column { flex: 0 1 100%; }
}

main > .columns > .column p:nth-of-type(2) {
  text-align: justify;
}
main > .columns > .column > p > img {
  max-width: 150px;
  transition: 0.3s ease;
}
main > .columns > .column > p > img:hover {
  max-width: 180px;
}
#greeting {
  padding-top: 0.1em;
  padding-bottom: 0.1em;
  min-height: 5em;
}
.collapse-button {
  background-color: #fff;
  cursor: pointer;
  border: none;
  font-size: 1em;
  padding-left: 0em;
}
.collapsed-content {
  display: none;
  overflow: hidden;
  background: #f3f3f3;
  text-align: center;
  padding: 1em 1em 1em 1em;
  max-width: 50em;
  box-shadow: -6px 0 6px rgba(213,213,213,0,0.9);
}