JSFiddle - React, Tailwind, and code Playground

HTML

<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/font-awesome/4.5.0/css/font-awesome.min.css">
<a href="#" class="btn btn-yellow fa fa-plus-circle">Дать объявление</a>

CSS

.btn-yellow {
  background: #fecc40;
  color: white;
  text-transform: uppercase;
  padding: 0 10px;
  line-height: 40px!important;
}
.fa {
  display: inline-block;
  font: normal normal normal 14px/1 FontAwesome;
  font-size: inherit;
  text-rendering: auto;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  transform: translate(0, 0);
}
.fa-plus-circle:before {
  content: "\f055";
  font-size: 40px;
  float: left;
}
a{
  text-decoration:none;
  }