.btn-group {
    width: 75%;
}

.btn-group .btn {
    width: 50%;
}

.animate {
    animation: fadein 2s;
    -moz-animation: fadein 2s; /* Firefox */
    -webkit-animation: fadein 2s; /* Safari and Chrome */
    -o-animation: fadein 2s; /* Opera */
}

@keyframes fadein {
    from {
        opacity: 0;
    }
    to {
        opacity: 1;
    }
}

@-moz-keyframes fadein { /* Firefox */
    from {
        opacity: 0;
    }
    to {
        opacity: 1;
    }
}

@-webkit-keyframes fadein { /* Safari and Chrome */
    from {
        opacity: 0;
    }
    to {
        opacity: 1;
    }
}

@-o-keyframes fadein { /* Opera */
    from {
        opacity: 0;
    }
    to {
        opacity: 1;
    }
}