.btn:before { content: ''; width: 0; height: 0; position: absolute; top: 0; left: 0; right: 0; bottom: 0; margin: auto; transition: all 0.3s ease; background: white; z-index: -1;}
.btn:before { content: ''; width: 0; height: 0; position: absolute; top: 0; left: 0; right: 0; bottom: 0; margin: auto; transition: all 0.3s ease; background: white; z-index: -1;}