Social media Buttons

как можно сделать такие кнопки с помощью css

Пример кода для кнопки Google

.google a {
    position:relative;
    border-color:#26478d;
    text-transform:lowercase;
    text-indent:16px;
    letter-spacing:40px;
    font: 65px/44px Georgia, Times New Roman, Times, serif;
    color:#fff;
    background:#1e3c7f;

    /* css3 */
    -moz-box-shadow:0 0 4px rgba(0,0,0,0.4);
    -webkit-box-shadow:0 0 4px rgba(0,0,0,0.4);
    box-shadow:0 0 4px rgba(0,0,0,0.4); /* standards version last */
    /* NOTE: webkit gradient implementation is not as per spec */
    background:-webkit-gradient(linear, left top, left bottom, from(#447aec), to(#1e3c7f));
    background:-moz-linear-gradient(top, #447aec, #1e3c7f);
}