html,
body,
header,
#intro {
    height: 100%;
}

#intro {
  background: url("../img/bgimages/about24nine.jpg");
    -webkit-background-size: cover;
    --moz-background-size: cover;
    -o-background-size: cover;
    background-size: cover;
}

.aboutheader {
  max-height: 50%;
}