It doesn't work last-child.

[Amritpal]

Why doesn't it work? :last-child ?

.group-list .user-name {
border-bottom: 1px solid #e2e2e2;
}
.group-list .user-name:last-child {
border-bottom: none;
 }

https://jsfiddle.net/lilubanana/96rz47oe/

.found-item {
  background: #fff;
  margin: 5px;
  padding: 5px 0;
  border-bottom: 1px solid #b6b6ba;
}
.found-item a {
  border-bottom: none;
}
.found-item a:hover {
  border-bottom: 1px solid #e8440d;
}
.found-item .user-name {
  padding: 5px 20px;
}
.found-item .user-name:hover {
  background: #e6e5e9;
}
.found-item .user-group {
  padding: 0 20px;
}
.found-item .icon-group {
  background-position: -13px -1215px;
  width: 14px;
  height: 14px;
  display: inline-block;
}
.group-title {
  text-transform: uppercase;
  font-weight: 600;
  font-size: 12px;
  padding-left: 25px;
  margin-top: 25px;
}
.group-list .user-name {
  border-bottom: 1px solid #e2e2e2;
}
.group-list .user-name:last-child {
  border-bottom: none;
}

<div class="group-list found-item">
  <a href="">
    <div class="user-name">
      <b>Теплов Алексей</b>
      <span class="pull-right"><span class="icons icon-phone"></span> 25-354</span>
      <div>руководитель группы</div>
    </div>
  </a>
  <a href="">
    <div class="user-name">
      <b>Теплищев Вадим</b>
      <span class="pull-right"><span class="icons icon-phone"></span> 25-354</span>
      <div>инженер</div>
    </div>
  </a>
<a href="">

<div class="user-name">

<b>Теплавина Евгения</b>

<span class="pull-right"><span class="icons icon-phone"></span> 25-354</span>

<div>инженер</div>

</div>

</a>

</div>

Every element but the last one needs border-bottom♪ Addendum last-child Border is somehow removed from all elements.

UPD

In this case, reference styles do not affect display. They got their style. text-decoration: none;

UPD 1.0

All savages with class .user-name Stylish-- border-bottom: 1px solid #e2e2e2;♪

The subject matter - the last diving class. .user-name Take it away. border-bottom

PS: All savages with class .user-name Inside the classroom .group-list♪

UPD 1.1

In addition to style border-bottom I only use savages with class. .user-name It doesn't matter what's inside of them.

[shizuka]

last-child Tega <а> That's it. <div class='username'>He is. first-child

To remove the backing of references a { text-decoration: none; }

.username b, .username span, .username div {
  border-bottom: 3px solid #FF0000;
}
.username :last-child {

border-bottom: none;

}

<div class='grouplist found-item'>

<a href=''>

<div class='username'>

<b>Теплов Алексей</b>

<span class='pullright'><span class='icons icon-phone'></span> 25-354</span>

<div>руководитель группы</div>

</div>

</a>

</div>