.btn {
  position: relative;
  margin: 30px auto;
  padding: 0;
  overflow: hidden;
  border-width: 0;
  outline: none;
  border-radius: 2px;
  box-shadow: 0 1px 4px rgba(0, 0, 0, 0.6);
  background-color: #e6f3ff;
  color: #004f99;
  transition: background-color .3s;
  font-size: 15px;
  cursor: pointer; }

.btn:hover, .btn:focus {
  background-color: #cce6ff; }

.btn > * {
  position: relative; }

.btn span {
  display: block;
  padding: 12px 24px; }

.btn:before {
  content: "";
  position: absolute;
  top: 50%;
  left: 50%;
  display: block;
  width: 0;
  padding-top: 0;
  border-radius: 100%;
  background-color: rgba(236, 240, 241, 0.3);
  -webkit-transform: translate(-50%, -50%);
  -moz-transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
  -o-transform: translate(-50%, -50%);
  transform: translate(-50%, -50%); }

.btn:active:before {
  width: 120%;
  padding-top: 120%;
  transition: width .2s ease-out, padding-top .2s ease-out; }