ble */
    code span.vs { color: #cc9393; } /* VerbatimString */
    code span.wa { color: #7f9f7f; font-weight: bold; } /* Warning */
    .display.math{display: block; text-align: center; margin: 0.5rem auto;}
    kbd {
        padding: 2px 4px ;
        font-size: 90%;
        color: #fff;
        background-color: #19a3be;
        border-radius: 3px;
        box-shadow: inset 0 -1px 0 rgba(0,0,0,.25);
    }
    html {
        line-height: 1.7;
        font-family: "Helvetica Neue", Helvetica, Arial, sans