keyboard.css

/* Adjust keyboard height and weight keeping a 3:1 ratio */

#keyboard {
    height                  : 250px; /* change as you like */
    width                   : 600px; /* change as you like */
    font-size               : 1em;   /* change accordingly */
    background-color        : #d5d9dc;
    border-radius           : 5%;
    box-shadow              : inset 0 0 8px #bbb,
    0 1px 0 #aaa,
    0 4px 0 #bbb,
    0 10px 30px #ddd;
    padding                 : 1%;
    font-family             : Helvetica, Arial, sans;
}

.keyboard-row {
    height                  : 20%;
    margin                  : 0 auto;
    text-align              : center;
}

.keyboard-row-left {
    text-align              : left;
}

.keyboard-key {
    background-color        : #eff0f2;
    border-radius           : 4px;
    border-top              : 1px solid #f5f5f5;
    box-shadow              : inset 0 0 25px #e8e8e8,
    0 1px 0 #c3c3c3,
    0 2px 0 #c9c9c9,
    0 2px 3px #333;
    color                   : #aaa;
    display                 : inline-block;
    height                  : 80%;
    line-height             : 2.5em;
    padding                 : 0.05% 1%;
    text-align              : center;
    text-transform          : uppercase;
    vertical-align          : top;
    width                   : 4.3%;
}

.keyboard-key-2rows {
    line-height             : 1.5em;
    font-size               : smaller;
}

.keyboard-key-space {
    width              : 34%;
}

.keyboard-key-tab {
    width              : 6.41%;
}

.keyboard-key-return {
    height             : 180%;
}