
<!doctype html>
<meta charset=utf-8>
<style>
.hr {
  color: gray;
  border-style: inset;
  border-width: 1px;
  margin: 0.5em auto;
  width: 100px;
}

.left {
  margin-left: 0;
}

.right {
  margin-right: 0;
}
</style>
<div class='hr'></div>
<div class='hr left'></div>
<div class='hr'></div>
<div class='hr right'></div>
<div class='hr'></div>

<div class='hr'></div>
<div class='hr left'></div>
<div class='hr'></div>
<div class='hr right'></div>
<div class='hr'></div>