.table_teclado tr td {
    background: #828282;
    color: #FFF;
    padding: 2em 3em;
    cursor: pointer;
    border-radius: 19px;
    font-family: sans-serif;
    border: 1px solid #fff;
    max-width: 20px;
    position: relative;
}

.table_teclado tr td:hover {
    background: #525252;
}

.btn_delete {
    position: absolute;
    left: .1em;
    bottom: .1em;
    width: 39px;
}

.btn_delete {
    position: absolute;
    left: .1em;
    bottom: .1em;
    width: 39px;
}

*, ::after, ::before {
    box-sizing: inherit !important;
} 

body {
    background: #A8C7D6;
}