<div class="block">
  <div class="block-info">
    <ul class="block-list">
      <li class="block-item">
        <a href="#" class="item-link">1</a>
      </li>
    </ul>
  </div>
</div>

.block {
  //...
}

.block-info {
  //...
}

.block-list {
  //...
}

.block-item {
  //...
  &:hover {
    //...
  }
  &:before {
    //...
  }
  &:after {
    //...
  }
}