CSS
html, body {
width: 100%;
height: 100%;
}
body {
background: #38f;
}
.the-button {
position: relative;
width: 100%;
height: 100%;
-webkit-border-radius: 50%;
-moz-border-radius: 50%;
border-radius: 50%;
padding: 0;
-webkit-box-shadow: 0 0 .5em rgba(0, 0, 0, 1), inset 0 .25em .3em rgba(255, 255, 255, .3), inset 0 -.25em .3em rgba(0, 0, 0, .5);
-moz-box-shadow: 0 0 .5em rgba(0, 0, 0, 1), inset 0 .25em .3em rgba(255, 255, 255, .3), inset 0 -.25em .3em rgba(0, 0, 0, .5);
box-shadow: 0 0 .5em rgba(0, 0, 0, 1), inset 0 .25em .3em rgba(255, 255, 255, .3), inset 0 -.25em .3em rgba(0, 0, 0, .5);
font: inherit;
cursor: pointer;
}
.the-button:before {
content:" ";
position: absolute;
left: 10%;
top: 10%;
width: 80%;
height: 80%;
background: -moz-linear-gradient(top, rgba(255, 255, 255, 0.14) 0%, rgba(255, 255, 255, 0) 50%, rgba(255, 255, 255, 0) 100%);
background: -webkit-gradient(linear, left top, left bottom, color-stop(0%, rgba(255, 255, 255, 0.14)), color-stop(50%, rgba(255, 255, 255, 0)), color-stop(100%, rgba(255, 255, 255, 0)));
background: -webkit-linear-gradient(top, rgba(255, 255, 255, 0.14) 0%, rgba(255, 255, 255, 0) 50%, rgba(255, 255, 255, 0) 100%);
background: -o-linear-gradient(top, rgba(255, 255, 255, 0.14) 0%, rgba(255, 255, 255, 0) 50%, rgba(255, 255, 255, 0) 100%);
background: -ms-linear-gradient(top, rgba(255, 255, 255, 0.14) 0%, rgba(255, 255, 255, 0) 50%, rgba(255, 255, 255, 0) 100%);
background: linear-gradient(to bottom, rgba(255, 255, 255, 0.14) 0%, rgba(255, 255, 255, 0) 50%, rgba(255, 255, 255, 0) 100%);
-webkit-border-radius: 50%;
-moz-border-radius: 50%;
border-radius: 50%;
}
.the-button:active {
-webkit-box-shadow: 0 0 .5em rgba(0, 0, 0, 1), inset 0 .1em .3em rgba(0, 0, 0, .5), inset 0 -.1em .3em rgba(0, 0, 0, .5);
-moz-box-shadow: 0 0 .5em rgba(0, 0, 0, 1), inset 0 .1em .3em rgba(0, 0, 0, .5), inset 0 -.1em .3em...