.linebehind {
  display: block;
  overflow: hidden;
  text-align: center;
}
.linebehind:before, 
.linebehind:after {
  content: "";
  display: inline-block;
  vertical-align: middle;
  position: relative;
  width: 50%;
  border-top-style: solid;
  border-top-width: 1px;
}
.linebehind:before {
  right: 0.5em;
  margin-left: -50%;
}
.linebehind:after {
  left: 0.5em;
  margin-right: -50%;
}