.keypad {position: absolute; width: 100%; bottom: 0;left: 0; top:0;}
.keypad table{position: absolute; bottom: 0; width:100%;text-align: center; vertical-align: middle; border-collapse: collapse; border-spacing: 0;}
.keypad table > tbody> tr > td {border: 1px solid #aaa; height: 65px;}
.keypad table button {width: 100%; height: 100%;margin: 0; padding: 0;border: none;background: #fff; outline: none;font-size: 20px;font-weight: lighter;}
.keypad table button.text-sm {font-size: 15px;}
.keypad table button:active {background: #efefef;}