.btn-ws {
  display:inline-block;
  background:#4CD137;
  color:#fff;
  font-weight:bold;
  padding:12px 20px;
  border-radius:6px;
  text-decoration:none;
  font-family:Arial, sans-serif;
  transition:opacity .2s ease;
}

.btn-ws:hover { opacity:0.85; }