کد:

.rc{display:block}
.rc ***
display:block;
height:1px;
overflow:hidden;
font-size:.01em;
background:#000000}
.rc1{
margin-left:3px;
margin-right:3px;
padding-left:1px;
padding-right:1px;
border-left:1px solid #919191;
border-right:1px solid #919191;
background:#3f3f3f}
.rc2{
margin-left:1px;
margin-right:1px;
padding-right:1px;
padding-left:1px;
border-left:1px solid #e5e5e5;
border-right:1px solid #e5e5e5;
background:#303030}
.rc3{
margin-left:1px;
margin-right:1px;
border-left:1px solid #303030;
border-right:1px solid #303030;}
.rc4{
border-left:1px solid #919191;
border-right:1px solid #919191}
.rc5{
border-left:1px solid #3f3f3f;
border-right:1px solid #3f3f3f}
.rcfg{
background:#000000}

<div>
  <b>
  <b><b></b></b>
  <b><b></b></b>
  <b></b>
  <b></b>
  <b></b></b>

  <div>

  </div>

  <b>
  <b></b>
  <b></b>
  <b></b>
  <b><b></b></b>
  <b><b></b></b></b>
</div>