Answers for "border css top and bottom only"

css border bottom

.bottomBorder {
  /*           width style color  */
  border-bottom: 5px solid black;
}

css border top

.topBorder {
  /*        width style color  */
  border-top: 5px solid black;
}

css border only top and bottom

#element{
  border-left:none;
  border-right:none;
}