.btn-icon {
  display: inline-block;
  max-width: 180px;
  text-align: left;
  background-color: #9ec34b;
  font-size: 16px;
  color: #FFF;
  text-decoration: none;
  font-weight: bold;
  padding: 8px 16px 8px 32px;
  border-radius: 4px;
  position: relative;
}

.btn-icon:before {
  font-family: "FontAwesome";
  content: "\f105";/* 好きなフォントアイコンを　*/
  position: absolute;
  left: 16px;
  top: 50%;
  margin-top: -8px;
}

.btn-icon:hover {
  opacity: 0.8;
}