html,body {
  padding: 0;
  margin: 0;
  -webkit-box-sizing: border-box;
  -moz-box-sizing: border-box;
  box-sizing: border-box;
}
body.about,
body.entry,
body.submit {
  overflow: hidden;
}

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

#header {
  width: 100%;
}

.cell {
  display: inline-block;
  width: 25vw;
  height: 20vw;
  color: white;
  text-shadow: 0 0 2px #000;
  cursor: pointer;
  background-size: cover;
  background-position: center center;
}

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

.cell:nth-child(2n+1) { background-color: #ddd; }
.cell:nth-child(2n+2) { background-color: #eee; }

.close {
  position: absolute;
  top: 10px;
  right: 10px;
  padding: 5px;
  font-size: 24px;
  color: white;
  background: black;
  border: 2px solid;
  cursor: pointer;
}

@media (max-width: 700px) {
  .cell {
    width: 100vw;
    height: 20vh;
  }
}