html,body {
}
body.about,
body.entry,
body.submit {
  overflow: hidden;
}

#about, #entry, #submit {
  position: fixed;
  top: 0; left: 0;
  width: 100%; height: 100%;
  background: #444;
  pointer-events: none;
  opacity: 0;
}
.about #about,
.entry #entry,
.submit #submit {
  opacity: 1;
  pointer-events: auto;
}

#header {
  width: 100%;
}

.cell {
  display: inline-block;
  width: 100vw;
  height: 20vw;
  color: white;
  text-shadow: 0 0 2px #000;
}

.media {
  width: 100%;
  max-height: 50vh;
}

.cell:nth-child(3n+1) { background: #800; }
.cell:nth-child(3n+2) { background: #880; }
.cell:nth-child(3n+3) { background: #808; }

@media screen and (max-width: 600px) {
  .cell {
    width: 100vw;
    height: 20vh;
  }
}