body {
  background: url(images/bliss-blur.jpg);
  display: flex;
  justify-content: center;
  background-attachment: fixed;
}

main {
  display: grid;
  width: 1000px;
  grid-template-columns: repeat(12, 1fr);
  & .image-box {grid-column: auto / span 6; margin: 0px 10px 20px 10px;}
  & img {width: 100%; border: solid gainsboro 1px;}
  & .figure-caption {color: gainsboro; font-family: Arial, sans-serif; font-size: 0.8em;}
}