margin-and-padding

elt {
  margin-{left|right|top|bottom}: 1px;
  margin: {all}; /* all */
  margin: {top} {right} {bottom} {left};
  margin: {top} {left-and-right} {bottom};
  margin: {top-and-bottom} {left-and-right};
  padding: /* as for margin */
  box-sizing: border-box; /* padding on inside of box, rather than outside -- use with width/height */
}