button,
.btn {
    font-family: inherit;
    font-size: 100%;
    color: rgba(0, 0, 0, 0.8);
    border: none transparent;
    background-color: #e6e6e6;
    text-decoration: none;
    border-radius: 2px;
}
button:focus,
.btn:not(.btn-close)focus,
button:hover,
.btn:not(.btn-close):hover 
{
    background-image: linear-gradient(
        transparent,
        rgba(0, 0, 0, 0.05) 40%,
        rgba(0, 0, 0, 0.1)
    );
}

button:active,
.btn:active {
    box-shadow: 0 0 0 1px rgba(0, 0, 0, 0.15) inset,
        0 0 6px rgba(0, 0, 0, 0.2) inset;
    border-color: #000;
}