.f-button {
  position: relative;
  font-family: inherit;
  font-size: 100%;
  line-height: 1.7;
  padding: 0.3em 0.5em;
  margin: 3px;
  color: #fff;
  border: 0;
  display: inline-block;
  background-color: #01b1f0;
  text-decoration: none;
  -webkit-appearance: none;
  border-radius: 3px;
  overflow: hidden;
  cursor: pointer;
  transition: 0.2s;
  box-shadow: 0 0 0 1px rgba(0,0,0,0.1) inset, 0 1px 0 1px rgba(255,255,255,0.1) inset;
}
.f-button.disabled {
  background-color: #aaa;  
}