buttons.css

a[class*="btn"] {text-decoration: none;}
input[class*="btn"], 
button[class*="btn"] {
    border: 0;
    font-family: Gill Sans, sans-serif;
    font-variant: small-caps;
}

.btn-3d {
	position: relative;
	display: inline-block;
	font-size: 2vw;
	padding: 20px 0;
    width: 100%;
	color: white;
	margin: 10px 0;
	border-radius: 6px;
	text-align: center;
	transition: top .01s linear;
	text-shadow: 0 1px 0 rgba(0,0,0,0.15);
}

.btn-3d.red:hover    {background-color: #DD4939;}
.btn-3d.blue:hover   {background-color: #699DD1;}
.btn-3d.green:hover  {background-color: #80C49D;}
.btn-3d.purple:hover {background-color: #D19ECB;}
.btn-3d.yellow:hover {background-color: #E9CB61;}
.btn-3d.cyan:hover   {background-color: #82D1E3;}

.btn-3d:active {
    top: 9px;
}
.btn-3d.red {
	background-color: #e74c3c;
	box-shadow: 0 0 0 1px #c63702 inset,
                0 0 0 2px rgba(255,255,255,0.15) inset,
                0 8px 0 0 #C24032,
                0 8px 0 1px rgba(0,0,0,0.4),
				0 8px 8px 1px rgba(0,0,0,0.5);
}
.btn-3d.red:active {
	box-shadow: 0 0 0 1px #c63702 inset,
				0 0 0 2px rgba(255,255,255,0.15) inset,
				0 0 0 1px rgba(0,0,0,0.4);
}

.btn-3d.blue {
	background-color: #6DA2D9;
	box-shadow: 0 0 0 1px #6698cb inset,
				0 0 0 2px rgba(255,255,255,0.15) inset,
				0 8px 0 0 rgba(110, 164, 219, .7),
				0 8px 0 1px rgba(0,0,0,.4),
				0 8px 8px 1px rgba(0,0,0,0.5);
}
.btn-3d.blue:active {
	box-shadow: 0 0 0 1px #6191C2 inset,
				0 0 0 2px rgba(255,255,255,0.15) inset,
				0 0 0 1px rgba(0,0,0,0.4);
}

.btn-3d.green {
	background-color: #82c8a0;
	box-shadow: 0 0 0 1px #82c8a0 inset,
				0 0 0 2px rgba(255,255,255,0.15) inset,
				0 8px 0 0 rgba(126, 194, 155, .7),
				0 8px 0 1px rgba(0,0,0,.4),
				0 8px 8px 1px rgba(0,0,0,0.5);
}
.btn-3d.green:active {
	box-shadow: 0 0 0 1px #82c8a0 inset,
				0 0 0 2px rgba(255,255,255,0.15) inset,
				0 0 0 1px rgba(0,0,0,0.4);
}

.btn-3d.purple {
	background-color: #cb99c5;
	box-shadow: 0 0 0 1px #cb99c5 inset,
				0 0 0 2px rgba(255,255,255,0.15) inset,
				0 8px 0 0 rgba(189, 142, 183, .7),
				0 8px 0 1px rgba(0,0,0,.4),
				0 8px 8px 1px rgba(0,0,0,0.5);
}
.btn-3d.purple:active {
	box-shadow: 0 0 0 1px #cb99c5 inset,
				0 0 0 2px rgba(255,255,255,0.15) inset,
				0 0 0 1px rgba(0,0,0,0.4);
}

.btn-3d.cyan {
	background-color: #7fccde;
	box-shadow: 0 0 0 1px #7fccde inset,
				0 0 0 2px rgba(255,255,255,0.15) inset,
				0 8px 0 0 rgba(102, 164, 178, .6),
				0 8px 0 1px rgba(0,0,0,.4),
				0 8px 8px 1px rgba(0,0,0,0.5);
}
.btn-3d.cyan:active {
	box-shadow: 0 0 0 1px #7fccde inset,
				0 0 0 2px rgba(255,255,255,0.15) inset,
				0 0 0 1px rgba(0,0,0,0.4);
}

.btn-3d.yellow {
	background-color: #F0D264;
	box-shadow: 0 0 0 1px #F0D264 inset,
				0 0 0 2px rgba(255,255,255,0.15) inset,
				0 8px 0 0 rgba(196, 172, 83, .7),
				0 8px 0 1px rgba(0,0,0,.4),
				0 8px 8px 1px rgba(0,0,0,0.5);
}
.btn-3d.yellow:active {
	box-shadow: 0 0 0 1px #F0D264 inset,
				0 0 0 2px rgba(255,255,255,0.15) inset,
				0 0 0 1px rgba(0,0,0,0.4);
}