These apply for padding and margin but mostly shown for padding.

Use values like 1px, 1em, or 1rem. Or 1.5 of something.

selector {
  padding: 1px;
  marging: 1px;
}

Top or bottom

selector {
  padding-top: 1px;
}

selector {
  padding-bottom: 1px;
}

Same for all sides

selector {
  padding: 1px;
}

Set top and bottom separately to sides

Set for TOP_BOTTOM LEFT_RIGHT.

selector {
  padding: 1px 2px;
}

Set for each side

Set for TOP, BOTTOM, LEFT, RIGHT.

selector {
  padding: 1px 2px 3px 4px;
}

Or

selector {
  padding-top: 1px;
  padding-bottom: 2px;
  padding-left: 3px;
  padding-right: 4px;
}