gistfile1.css

.button
{
    margin: 10px;
    text-decoration: none;
    font: bold 1.5em 'Trebuchet MS',Arial, Helvetica; /*Change the em value to scale the button*/
    display: inline-block;
    text-align: center;
    color: #fff;

    border: 1px solid #9c9c9c; /* Fallback style */
    border: 1px solid rgba(0, 0, 0, 0.3);            

    text-shadow: 0 1px 0 rgba(0,0,0,0.4);

    box-shadow: 0 0 .05em rgba(0,0,0,0.4);
    -moz-box-shadow: 0 0 .05em rgba(0,0,0,0.4);
    -webkit-box-shadow: 0 0 .05em rgba(0,0,0,0.4);

}

.button, .button span
{
    -moz-border-radius: .3em;
    border-radius: .3em;
}

.button span
{
    border-top: 1px solid #fff; /* Fallback style */
    border-top: 1px solid rgba(255, 255, 255, 0.5);
    display: block;
    padding: 0.5em 2.5em;

    /* The background pattern */

    background-image: -webkit-gradient(linear, 0 0, 100% 100%, color-stop(.25, rgba(0, 0, 0, 0.05)), color-stop(.25, transparent), to(transparent)),
                      -webkit-gradient(linear, 0 100%, 100% 0, color-stop(.25, rgba(0, 0, 0, 0.05)), color-stop(.25, transparent), to(transparent)),
                      -webkit-gradient(linear, 0 0, 100% 100%, color-stop(.75, transparent), color-stop(.75, rgba(0, 0, 0, 0.05))),
                      -webkit-gradient(linear, 0 100%, 100% 0, color-stop(.75, transparent), color-stop(.75, rgba(0, 0, 0, 0.05)));
    background-image: -moz-linear-gradient(45deg, rgba(0, 0, 0, 0.05) 25%, transparent 25%, transparent),
                      -moz-linear-gradient(-45deg, rgba(0, 0, 0, 0.05) 25%, transparent 25%, transparent),
                      -moz-linear-gradient(45deg, transparent 75%, rgba(0, 0, 0, 0.05) 75%),
                      -moz-linear-gradient(-45deg, transparent 75%, rgba(0, 0, 0, 0.05) 75%);

    /* Pattern settings */

    -moz-background-size: 3px 3px;
    -webkit-background-size: 3px 3px;
}

.button:hover
{
    box-shadow: 0 0 .1em rgba(0,0,0,0.4);
    -moz-box-shadow: 0 0 .1em rgba(0,0,0,0.4);
    -webkit-box-shadow: 0 0 .1em rgba(0,0,0,0.4);
}

.button:active
{
    /* When pressed, move it down 1px */
    position: relative;
    top: 1px;
}

gistfile2.css

.button-blue
{
    background: #4477a1;
    background: -webkit-gradient(linear, left top, left bottom, from(#81a8cb), to(#4477a1) );
    background: -moz-linear-gradient(-90deg, #81a8cb, #4477a1);
    filter:  progid:DXImageTransform.Microsoft.gradient(GradientType=0,startColorstr='#81a8cb', endColorstr='#4477a1');
}

.button-blue:hover
{
    background: #81a8cb;
    background: -webkit-gradient(linear, left top, left bottom, from(#4477a1), to(#81a8cb) );
    background: -moz-linear-gradient(-90deg, #4477a1, #81a8cb);
    filter:  progid:DXImageTransform.Microsoft.gradient(GradientType=0,startColorstr='#4477a1', endColorstr='#81a8cb');
}

.button-blue:active
{
    background: #4477a1;
}

gistfile3.html

<a href="#" class="button button-blue">
    <span>Button</span>
</a>