<a class="button" href="#">Press me!</a>

@import 'https://fonts.googleapis.com/css?family=Rubik+One';

body, html { 
  margin: 0; 
  padding: 0; 
  height: 100%; 
  width: 100%; 
  background: #e53935;
  background: linear-gradient(to left, #e53935 , #e35d5b);
}

%test {
  position: absolute;
	content: '';
	transition: all .5s;
}

.button { 
	display: inline-block; 
	padding: 20px 40px;
	color: white;
	position: absolute;
	top: 50%;
	left: 50%;
	transform: translate(-50%, -50%);
	vertical-align: middle;
	font-family: 'Rubik One', sans-serif;
	text-decoration: none;
	font-size: 4vw;
	transition: all .5s;
	background-color: #3498db;

	&::before {
    @extend %test;
		bottom: -15px;
		height: 15px;
		width: 100%;
		left: 8px;
		transform: skewX(45deg);
		background-color: darken(#3498db, 20%);
	}

	&::after {
		@extend %test;
		right: -15px;
		height: 100%;
		width: 15px;
		bottom: -8px;
		transform: skewY(45deg);
		background-color: darken(#3498db, 30%);
	}

	&:active {
		margin-left: 10px;
		margin-top: 10px;
		&::before {
			bottom: -5px;
			height: 5px;
			left: 3px;
		}
		
    &::after {
			right: -5px;
			width: 5px;
			bottom: -3px;
		}	
	}
}