.btn.btn-loading {
    background-image: -webkit-gradient(linear, 0 0, 100% 100%,
        color-stop(.25, rgba(0, 0, 0, .10)),
        color-stop(.25, transparent),
        color-stop(.5, transparent),
        color-stop(.5, rgba(0, 0, 0, .10)),
        color-stop(.75, rgba(0, 0, 0, .10)),
        color-stop(.75, transparent),
        to(transparent));
    background-image:
        -moz-linear-gradient(-45deg,
            rgba(0, 0, 0, .10) 25%,
            transparent 25%,
            transparent 50%, rgba(0, 0, 0, .10) 50%,
            rgba(0, 0, 0, .10) 75%,
            transparent 75%, transparent
        );
    background-size: 50px 50px;
    -moz-background-size: 50px 50px;
    -webkit-background-size: 50px 50px;
    -webkit-animation: animate-stripes 2s linear infinite;
}

@-webkit-keyframes animate-stripes {
    from {
        background-position: 0 0;
    }
    to {
       background-position: -50px 0;
    }
}