vimwiki

Center absolute element

/* horizontally */
element {
  position: absolute;
  left: 0;
  right: 0;
  margin: 0 auto;
}

/* vertically */
element {
  position: absolute;
  top: 0;
  bottom: 0;
  margin: auto 0;
}

/* both */
element {
  position: absolute;
  left: 0;
  right: 0;
  top: 0;
  bottom: 0;
  margin: auto;
}