div.my-footer {
    position: absolute;
    bottom: 0px;
    left: 0px;
    height: 20px;
    width: 100%;
}
div.my-footer span {
    font-size: 10pt;
    position: absolute;
    left: 15px;
    bottom: 2px;
} 

div.ref span {
    font-size: 20pt;
} 
:root {
  /* Fonts */
  --text-font-family: Arial;
  --text-font-is-google: 1;
  --text-font-family-fallback: -apple-system, BlinkMacSystemFont, avenir next, avenir, helvetica neue, helvetica, Ubuntu, roboto, noto, segoe ui, arial;
  --text-font-base: sans-serif;
  --header-font-family: Arial;
  --header-font-is-google: 1;
  --header-font-family-fallback: Georgia, serif;
  --code-font-family: 'Fira Mono';
  --code-font-is-google: 1;
  --base-font-size: 20px;
  --text-font-size: 1.5rem;
  --code-font-size: 0.9rem;
  --code-inline-font-size: 1em;
  --header-h1-font-size: 2.75rem;
  --header-h2-font-size: 2.25rem;
  --header-h3-font-size: 1.75rem;

  /* Colors */
  --text-color: #272822;
  --header-color: #507c5c;
  --background-color: #FFFFFF;
  --link-color: #507c5c;
  --text-bold-color: #507c5c;
  --code-highlight-color: rgba(255,255,0,0.5);
  --inverse-text-color: #FFFFFF;
  --inverse-background-color: #305c3c;
  --inverse-header-color: #FFFFFF;
  --inverse-link-color: #507c5c;
  --title-slide-background-color:  #305c3c;
  --title-slide-text-color: #FFFFFF;
  --header-background-color: #507c5c;
  --header-background-text-color: #FFFFFF;
  --base: #5c5c5c;
  --white: #FFFFFF;
  --black: #272822;
}