<div class="container">
  <h1>Pure Css Button Hover effect</h1>
  
  <a href="#" class="button">Hover me</a>
  
<!--  optional  -->
  <span>Made by <a href="http://alticreation.com/en">alticreation.com</a></span>
</div>  

$color: #0cf;

.button {
	display: inline-block;
	padding: .75rem 1.25rem;
	border-radius: 10rem;
	color: #fff;
	text-transform: uppercase;
	font-size: 1rem;
	letter-spacing: .15rem;
	transition: all .3s;
	position: relative;
	overflow: hidden;
	z-index: 1;
	&:after {
		content: '';
		position: absolute;
		bottom: 0;
		left: 0;
		width: 100%;
		height: 100%;
		background-color: $color;
		border-radius: 10rem;
		z-index: -2;
	}
	&:before {
		content: '';
		position: absolute;
		bottom: 0;
		left: 0;
		width: 0%;
		height: 100%;
		background-color: darken($color, 15%);
		transition: all .3s;
		border-radius: 10rem;
		z-index: -1;
	}
	&:hover {
		color: #fff;
		&:before {
			width: 100%;
		}
	}
}

/* optional reset for presentation */
* {
  font-family: Arial;
  text-decoration: none;
  font-size: 20px;
}
.container {
  padding-top: 50px;
  margin: 0 auto;
  width: 100%;
  text-align: center;
}
h1 {
  text-transform: uppercase;
  font-size: .8rem;
  margin-bottom: 2rem;
  color: #777;
}
span {
  display: block;
  margin-top: 2rem;
  font-size: .7rem;
  color: #777;
  a {
    font-size: .7rem;
    color: #999;
    text-decoration: underline;
  }
}