:root {
  --width-target:      calc(100vw / 6);
  --height-target:     calc(100vh / 4);
  --size:              min(var(--width-target), var(--height-target));
  --margin-vertical:   calc((100vh - var(--size) * 2.5) / 2);
  --margin-horizontal: calc((100vw - var(--size) * 5) / 2);
}

* {
  margin:  0;
  padding: 0;
}

html {
  background-color: black;
  color:            white;
  font-family:      sans-serif;
  font-size:        var(--size);
  line-height:      var(--size);
  overflow:         hidden;
  text-align:       center;
}

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

#intermodal {
  display:               grid;
  grid-template-columns: repeat(5, 1fr);
  margin-bottom:         var(--margin-vertical);
  margin-left:           var(--margin-horizontal);
  margin-right:          var(--margin-horizontal);
  margin-top:            var(--margin-vertical);
}

#intermodal > * {
  width: var(--size);
}

#intermodal > div {
  height: var(--size);
  text-shadow: 0 0 5px #fff;
}

#intermodal > a {
  align-items:     center;
  display:         flex;
  font-size:       calc(var(--size) / 9);
  height:          calc(var(--size) / 2);
  justify-content: center;
  line-height:     calc(var(--size) / 9);
}

a:hover {
  text-shadow: 0 0 5px #fff;
}

/* intermodal is an isogram */
#i:after        { content: 'I';  }
#i:hover:after  { content: '私'; }
#n:after        { content: 'N';  }
#n:hover:after  { content: '∅';  }
#t:after        { content: 'T';  }
#t:hover:after  { content: '࿈';  }
#e:after        { content: 'E';  }
#e:hover:after  { content: 'Ə';  }
#r:after        { content: 'R';  }
#r:hover:after  { content: 'ℜ';  }
#m:after        { content: 'M';  }
#m:hover:after  { content: '☾';  }
#o:after        { content: 'O';  }
#o:hover:after  { content: 'ꙮ';  }
#d:after        { content: 'D';  }
#d:hover:after  { content: '↓';  }
#a:after        { content: 'A';  }
#a:hover:after  { content: 'א';  }
#l:after        { content: 'L';  }
#l:hover:after  { content: 'し'; }