<!DOCTYPE html>
<style>
.outer-f {
  color: red;
}
.fl-atomic {
  display: inline-block;
}
.inner-f {
  color: lime;
}
</style>
<div>
<span class="outer-f">FIRST</span> <div class="fl-atomic"><span class="inner-f">first</span><br>second</div> <span class="outer-f">FIRST</span>
</div>