custom.css

body:before {
    content: 'Youpi dansons la Kapoeira !';
    font-family: Georgia, serif;
    position: fixed;
    padding: 1em;
    width: 100%;
    bottom: 0;
    height: 2em;
    color: #8B0000;
    background-color: lightgrey;
    text-align: center;
    font-size: 1rem;
}

body:after {
    content: 'Johanna Vauchel and Mehdi Rebiai';
    font-family: Georgia, serif;
    position: fixed;
    padding: 1em;
    bottom: 0;
    left: 1em;
    height: 2em;
    font-size: 1rem;
    color: #8B0000;
    text-align: center;
}

.reveal:before {
    content: ' ';
    position: fixed;
    padding: 1em;
    width: 10em;
    height: 10em;
    background: url("data:image/png;base64,${QRCODE_PNG_BASE64}");
    background-repeat: no-repeat;
}

.reveal:after {
    content: ' ';
    position: fixed;
    top: 0;
    right: 0;
    padding: 1em;
    width: 10em;
    height: 10em;
    background: url("data:image/png;base64,${CONFERENCE_PNG_BASE64}");
    background-repeat: no-repeat;
    background-position: right top;
}

.reveal h2 {
    color: #8B0000;
}

.reveal h1 {
    color: #8B0000;
}

.footer {
    position: absolute;
    display: table;
    width: 100%;
    bottom: 0;
    color: #0988d5
}

.reveal code {
    font-size: 0.7em;
    line-height: 1.2em;
}