a.bttn {
  color: #00a3df;
  text-decoration: none;
  -webkit-transition: 0.3s all ease;
  transition: 0.3s ease all;
}
a.bttn:hover {
  color: #FFF;
}
a.bttn:focus {
  color: #FFF;
}

.bttn {
  margin:0;
  font-size: 1.3vw;
  letter-spacing: 1px;
  text-transform: uppercase;
  display: inline-block;
  text-align: center;
  width: auto;
  font-weight: bold;
  padding: .6vw;
  border: 2px solid #00a3df;
  border-radius: 2px;
  position: relative;
  box-shadow: 0 2px 10px rgba(0, 0, 0, 0.16), 0 3px 6px rgba(0, 0, 0, 0.1);
}
.bttn:before {
  -webkit-transition: 0.5s all ease;
  transition: 0.5s all ease;
  position: absolute;
  top: 0;
  left: 50%;
  right: 50%;
  bottom: 0;
  opacity: 0;
  content: '';
  background-color: #00a3df;
  z-index: -2;
}
.bttn:hover:before {
  -webkit-transition: 0.5s all ease;
  transition: 0.5s all ease;
  left: 0;
  right: 0;
  opacity: 1;
}
.bttn:focus:before {
  transition: 0.5s all ease;
  left: 0;
  right: 0;
  opacity: 1;
}



/* Mobil Responsive */
@media screen and (max-width: 600px) {
	.bttn {font-size: 3vw}
}