slides.css

/* core typography styles */
body {
  font-family: Open Sans, sans-serif;
  line-height: 1.4;
  scroll-snap-type: proximity;
  scroll-snap-padding: 2vh 2vw;
}
h1, h2, h3, .h, .slide::before {
  font-family: "Bauhaus 93", "Impact", "Arial Black", sans-serif;
  line-height: 1.1;
}
h1, h2, .h {
  text-align: center;
  margin-top: 2em;
}

@media not print {
  /* slide styles */
  body {
    background-color: #302;
  }
  h1, h2 {
    text-shadow: royalBlue -2px -1px 0;
    letter-spacing: 3px;
    font-size: 300%;
    margin: 0 5vh 0 2vh;
  }
  header p {
    text-align: center;
  }
  .slide {
    display: block;
    display: flex;
    flex-direction: column;
    justify-content: space-around;
    align-items: stretch;

    position: relative;
    scroll-snap-align: start;

    overflow-x: hidden;
    overflow-y: auto;
    box-sizing: border-box;
    width: 95%;
    width: calc(100% - 1vw);
    max-width: 50em;
    height: 96vh;
    padding: 1em;
    border-radius: 1em;
    margin: 2vh auto;

    box-shadow: 0.2em 0.3em 0.5em 0 black;
    background-color: tomato;
    background-image: radial-gradient(circle farthest-side, transparent 60%, gold 125%);
    color:  indigo;
  }
  .slide[data-section-slug]::before {
    content: attr(data-section-slug);
    display: block;
    position: absolute;
    background: lightBlue;
    box-shadow: indigo 0 0 1em;
    box-sizing: border-box;
    padding: 3em 5em 1em;
    width: 16em;
    top: 0;
    right: -8em;
    text-align: center;
    transform-origin: center top;
    transform: rotate(45deg);
    z-index: 100;
  }
  .slide[data-section-slug] {
    padding-top: 4em;
  }
  .slide.text-only {
    justify-content: center; /* don't add extra spaces between paragraphs */
  }
  .slide > * {
    flex: none; /* default for text paragraphs & headers */
    margin: 0.2em 0;
  }
  .slide > *:first-child {
    margin-top: 0; /* margin will be set by padding on slide */
  }
  .slide > h2:only-child {
    position: absolute; /* so that 100% includes parent padding */
    width: 100%;
    padding: 10vh 1em;
    box-sizing: border-box;
    align-self: center;
    left: 0; /* align flush to edge even if flex is not supported */
    margin: 0;
    background: lightBlue;
  }
  /* the story, revised */
  .slide > strong {
    display: block;
    background: #ffec80;
    font-size: 150%;
    text-align: center;
    padding: 1em;
  }
  ins, del {
    color: darkRed;
    font-weight: normal;
  }
  ins {
    text-decoration: none;
    background: none;
    font-family: "Segoe Print", "Comic Sans", "Comic Sans MS", sans-serif;
  }
  ins code, del code {
    color: inherit;
    font-family: Segoe UI, monospace;
  }
  .editor2 {
    color: mediumBlue;
  }
  @supports (text-decoration-color: red) {
    del {color: inherit; text-decoration-color: darkRed;}
    del.editor2 {color: inherit; text-decoration-color: mediumBlue;}
  }
  .slide > object:only-child {
    height: auto;
    overflow: hidden;
    min-height: 0;
    flex: 1;
    margin: 0;
  }
  /* figures and demos */
  .slide > figure{
    height: 100%;
    max-height: 96vh;
    width: 100%;
    margin: 0 auto;
    box-sizing: border-box;
    flex: 1;
    min-height: 0;
    overflow: auto;
  }
  .slide > figure {
    display: flex;    
  }
  figure > img, figure > object {
    display: block;
    object-fit: contain;
    object-position: center center;
    max-height: 100%;
    width: 100%;
    margin: 0 auto;
    min-height: 0;
  }
  /* credit lines for images */
  .slide small {
    font-size: 75%;
    display: block;
    margin-left: auto;
    text-align: right;
    max-width: 70%;
  }
  table {
    font-size: 80%;
    line-height: 1.1;
    background: lightBlue;
    border-collapse: collapse;
    margin: auto;
  }
  td, th {
    border: solid royalBlue;
    padding: 0.25em 0.5em;
  }
  th {
    font-weight: bold;
    background: indigo;
    color: lightBlue;
  }
  li > p {
    margin: 0.3em 0;
  }  
  pre {
    background: indigo;
    color: lightBlue;
    padding: 0.5em;
    margin: 0.2em;
    white-space: pre-wrap;
    overflow: auto;
    flex: 1;
  }
  :not(a):focus {
      outline: none;
      border-right: solid #302;
  }
  :link { color: darkblue;}
}
@media (max-height: 30em), (max-width: 20em) {
  .slide {
    height: auto;
    min-height: 10em;
  }
  .slide > figure {
    min-height: 16em;
  }
}
@media (min-width: 35em) {
    html {
        font-size: 150%;
    }
    li li {
        font-size: 80%;
    }
    .slide {
        padding: 1em 2em;
        width: calc(100% - 2vw);
    }
}
@media (min-width: 50em) AND (min-height: 40em) {
    html {
        font-size: 200%;
    }
    .slide {
        padding: 1em 3em;
    }
}
@supports (transition: opacity 1s) {
  ins, del {
    will-change: opacity;
  }
  ins {
    transition-property: opacity;
  }
  del {
    transition-property:  text-decoration, opacity;
  }
  .slide:focus + .slide > strong ins:not(.old-edits) {
    opacity: 0;
    transition-delay: 0s;
    transition-duration: 0.1s;
  }
  .slide:focus > strong ins {
    opacity: 1;
    transition-duration: 0.5s;
  }
  .slide:focus > strong del {
    opacity: 0;
    transition-duration: 0s, 1s;
  }
  ins:nth-of-type(1) {
    transition-delay: 0.3s;
  }
  ins:nth-of-type(2) {
    transition-delay: 0.6s;
  }
  ins:nth-of-type(3) {
    transition-delay: 0.9s;
  }
  ins:nth-of-type(4) {
    transition-delay: 1.2s;
  }
  ins:nth-of-type(n + 5) {
    transition-delay: 1.5s;
  }
  del:nth-of-type(1) {
    transition-delay: 0.3s, 1.3s;
  }
  del:nth-of-type(2) {
    transition-delay: 0.3s, 1.6s;
  }
  del:nth-of-type(3) {
    transition-delay: 0.3s, 1.9s;
  }
  del:nth-of-type(4) {
    transition-delay: 0.3s, 2.2s;
  }
  del:nth-of-type(n + 5) {
    transition-delay: 0.3s, 2.5s;
  }
}
@keyframes stagger-ins {
  0%, 25% {position: static}
  100% {position: static; opacity: 1}
}
@keyframes stagger-del {
  0%, 25% {font-weight: normal;}
  25% {text-decoration-line: line-through; text-decoration-color: transparent;}
  100% {text-decoration-line: line-through; text-decoration-color: darkRed;}
}

@media print {
    .slide {
        break-inside: auto;
    }
    .slide:not(:last-child) {
        border-bottom: solid lightGray;
    }
    a:link, a:visited {
       color: inherit;
       text-decoration: none;
    }
    a:link::after {
        content: " (" attr(href) ")";
    }
    a.literal::after {
        content: normal;
    }
    h2 br, h3 br {display: none;}
    figure > img, figure > object, .slide > object, figure > svg {
      max-height: 50vmin;
      min-height: 10em;
    }
}