hbox {
  display: -moz-flex;
  display: -webkit-flex;
  display: -ms-flex;
  display: flex;
  -moz-flex-direction: row;
  -webkit-flex-direction: row;
  -ms-flex-direction: row;
  flex-direction: row;
}
vbox {
  display: -moz-flex;
  display: -webkit-flex;
  display: -ms-flex;
  display: flex;
  -moz-flex-direction: column;
  -webkit-flex-direction: column;
  -ms-flex-direction: column;
  flex-direction: column;
}

vbox[align=start],
hbox[align=start] {
  -moz-justify-content: flex-start;
  -webkit-justify-content: flex-start;
  -ms-justify-content: flex-start;
  justify-content: flex-start;
}
vbox[align=end],
hbox[align=end] {
  -moz-justify-content: flex-end;
  -webkit-justify-content: flex-end;
  -ms-justify-content: flex-end;
  justify-content: flex-end;
}
vbox[align=center],
hbox[align=center] {
  -moz-justify-content: center;
  -webkit-justify-content: center;
  -ms-justify-content: center;
  justify-content: center;
}
/* TODO there's no align=stretch */

vbox[pack=start],
hbox[pack=start] {
  -moz-align-items: flex-start;
  -webkit-align-items: flex-start;
  -ms-align-items: flex-start;
  align-items: flex-start;
}
vbox[pack=end],
hbox[pack=end] {
  -moz-align-items: flex-end;
  -webkit-align-items: flex-end;
  -ms-align-items: flex-end;
  align-items: flex-end;
}
vbox[pack=center],
hbox[pack=center] {
  -moz-align-items: center;
  -webkit-align-items: center;
  -ms-align-items: center;
  align-items: center;
}