.btn{
color: #222;
position: relative;
//top: 50%;
//left: 50%;
//transform: translate(-50%, -50%);
text-transform: uppercase;
letter-spacing: .2em;
-webkit-transition: all .4s cubic-bezier(0.645, 0.045, 0.355, 1);
transition: all .4s cubic-bezier(0.645, 0.045, 0.355, 1);
// font-size: 0.875em;
//width: 140px;
//text-align: center;
//padding: 10px 15px;
}
.btn:hover{
//letter-spacing: 0;
color: white
}
.btn:after{
content: "";
position: absolute;
left: 0;
bottom: 0;
width: 100%;
height: 0;
background: #6284FF;
z-index: -1;
-webkit-transition: all .4s cubic-bezier(0.645, 0.045, 0.355, 1);
transition: all .4s cubic-bezier(0.645, 0.045, 0.355, 1);
}
.btn:hover:after{
height: 100%;
}