/* Style for the slides for TPAC 2023, to be used together with the
   Shower script or the b6+ script. For usage instructions, see
   https://www.w3.org/2023/Talks/TPAC/Templates/Overview.html

   TODO: Styles for blockquotes?

   TODO: Provide a fallback for side images for UAs that do not
   implement 'object-fit'?

   TODO: .greeked is visually hidden, but assistive technology still
   sees it and speaks it. Can that be fixed? ('speak: never' has no
   effect.)

   TODO: with .clear, not only remove the side banner and slide
   number, but also make the slide wider (i.e., remove the padding
   where the side banner was). This requires rules for for slides with
   side images and elements with class=place, too

   Layout of a slide:

   +-------+---------------------------------------+
   | LOGO  |                   2em                 |
   |       |   +-------------------------------+   |
   |       |   |                               |   |  ^
   |       |   |                               |   |  |
   |  4em  |2em|                               |2em| 23em
   |       |   |                               |   |  |
   |       |   |                               |   |  v
   |       |   +-------------------------------+   |
   |  nr.  |                   1em                 |
   +-------+---------------------------------------+

   A = 16/9         = aspect ratio
   N = 23           = height in em (i.e., 21 lines + 2 x 1 em padding)
   L = 4            = logo width in em
   H = 86/120.31532 = logo aspect ratio (width/height)
   C = 2            = font size (and logo size) multiplier for cover pages
   w = N*A          = width of slide in em

   Created: 31 July 2023
   Author: Bert Bos <bert@w3.org>

   Copyright © 2023 World Wide Web Consortium (W3C Inc, European
   Research Consortium for Informatics and Mathematics, Keio
   University, Beihang). All Rights Reserved. This work is distributed
   under the W3C® Software License[1] in the hope that it will be
   useful, but WITHOUT ANY WARRANTY; without even the implied warranty
   of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

   [1] http://www.w3.org/Consortium/Legal/copyright-software
*/

@font-face {
  font-family: My Lato;
  font-style: italic;
  font-weight: 400;
  font-display: swap;
  src: url(Lato-Italic.woff2) format("woff2"),
    url(Lato-Italic.woff) format("woff");
  src: local(Lato Italic), local(Lato-Italic),
    url(Lato-Italic.woff2) format("woff2"),
    url(Lato-Italic.woff) format("woff")}

@font-face {
  font-family: My Lato;
  font-style: normal;
  font-weight: 400;
  font-display: swap;
  src: url(Lato-Regular.woff2) format("woff2"),
    url(Lato-Regular.woff) format("woff");
  src: local(Lato Regular), local(Lato-Regular),
    url(Lato-Regular.woff2) format("woff2"),
    url(Lato-Regular.woff) format("woff")}

@font-face {
    font-family: My Lato;
    font-style: normal;
    font-weight: bold;
    font-display: swap;
    src: url(Lato-Bold.woff2) format("woff2"),
	 url(Lato-Bold.woff) format("woff");
    src: local(Lato Bold), local(Lato-Bold),
	 url(Lato-Bold.woff2) format("woff2"),
	 url(Lato-Bold.woff) format("woff");
}
@font-face {
    font-family: My Lato;
    font-style: italic;
    font-weight: bold;
    font-display: swap;
    src: url(Lato-BoldItalic.woff2) format("woff2"),
	 url(Lato-BoldItalic.woff) format("woff");
    src: local(Lato Bold Italic), local(Lato-BoldItalic),
	 url(Lato-BoldItalic.woff2) format("woff2"),
	 url(Lato-BoldItalic.woff) format("woff");
}
@font-face {
  font-family: My Montserrat;
  font-style: italic;
  font-weight: 900;
  font-display: swap;
  src: url(Montserrat-BlackItalic.woff2) format("woff2"),
       url(Montserrat-BlackItalic.woff) format("woff");
  src: local(Montserrat Black Italic), local(Montserrat-BlackItalic),
       url(Montserrat-BlackItalic.woff2) format("woff2"),
       url(Montserrat-BlackItalic.woff) format("woff");
}
@font-face {
  font-family: My Montserrat;
  font-style: normal;
  font-weight: 900;
  font-display: swap;
  src: url(Montserrat-Black.woff2) format("woff2"),
       url(Montserrat-Black.woff) format("woff");
  src: local(Montserrat Black), local(Montserrat-Black),
       url(Montserrat-Black.woff2) format("woff2"),
       url(Montserrat-Black.woff) format("woff");
}

@font-face {
  font-family: My Montserrat;
  font-style: italic;
  font-weight: bold;
  font-display: swap;
  src: url(Montserrat-BoldItalic.woff2) format("woff2"),
       url(Montserrat-BoldItalic.woff) format("woff");
  src: local(Montserrat BoldItalic), local(Montserrat-BoldItalic),
       url(Montserrat-BoldItalic.woff2) format("woff2"),
       url(Montserrat-BoldItalic.woff) format("woff");
}

@font-face {
  font-family: My Montserrat;
  font-style: normal;
  font-weight: bold;
  font-display: swap;
  src: url(Montserrat-Bold.woff2) format("woff2"),
       url(Montserrat-Bold.woff) format("woff");
  src: local(Montserrat Bold), local(Montserrat-Bold),
       url(Montserrat-Bold.woff2) format("woff2"),
       url(Montserrat-Bold.woff) format("woff");
}


/* Common layout independent of slide mode */
html {font: 400 1em/1.3 My Lato, Carlito, Calibri, Open Sans, Helvetica Neue,
    Helvetica, Arial, Liberation Sans, Noto Emoji, Noto Sans Symbols,
    sans-serif;
  background: none; /* Make sure the background of body gets used */
  font-size-adjust: 0.506 /* Lato Regular */; letter-spacing: 0.02em}
body {background: url(linen.png) #595b60; counter-reset: slide;
  margin: 2em; color: white}
b {font-weight: bold}
dt {font-weight: bold}
dd {margin: 0}
h4 {font-size: 1em; margin: 0.5em 0}
.slide p, .slide ul, .slide ol, .slide pre, .slide blockquote, .slide li {
  margin: 0 0 0.6em 0}
.slide h1, .slide h2, .slide address {margin: 0 0 0.6em 0;
  font: 900 2em/1.1 My Montserrat, Arial Black, Myriad Pro, Roboto, sans-serif;
  font-size-adjust: 0.542}
.slide address {color: hsl(356,67%,40%); font-size: 1.4em}
.slide address :link, .slide address :visited {color: inherit}
.slide h3 {font-size: 1.1em; color: hsl(356,67%,40%);
  margin: 0.8em 0 0.48em 0}
.full, .slide, .comment {width: 40.889rem; /*= w */ height: 23rem; /*= N */}
.slide {color: black; box-shadow: 0 0.4em 0.6em #000;
  line-height: 1.6;
  word-break: normal; overflow-wrap: normal; letter-spacing: normal;
  padding: 2em 2em 1em 6em /*= L + 2 */;
  position: relative;
  box-sizing: border-box; z-index: 0; display: inline-block;
  margin: 4em 2em 0 0; vertical-align: bottom; counter-increment: slide;
  border-radius: 0.5rem;
  text-shadow: 0 -1px hsl(0,0%,98%), 1px 0 hsl(0,0%,98%),
    0 1px hsl(0,0%,98%), -1px 0 hsl(0,0%,98%),
    -0.7px -0.7px hsl(0,0%,98%), 0.7px -0.7px hsl(0,0%,98%),
    0.7px 0.7px hsl(0,0%,98%), -0.7px 0.7px hsl(0,0%,98%);
  background: hsl(0,0%,98%)}
.clear .slide, .slide.clear {background: hsl(0,0%,98%)}
.slide:target {outline: lime solid 0.5em; outline-offset: 1em}
.slide h3 a {color: inherit}
.watermark {color: red; font-size: 400%}

/* EM elements get a highlighter-like background */
.slide em {font-style: normal; padding-left: 0.1em; padding-right: 0.1em;
  text-shadow: none; background:  hsl(62,100%,50%)}

/* Lists with less indent */
.slide li {margin-left: 1em}
.slide ol, .slide ul {padding: 0}
.slide li ul, .slide li ol, .slide li li {margin-top: 0.1em; margin-bottom: 0.2em}

/* Own counter, because FF & Safari don't apply text-shadow to the default. */
.slide ol {counter-reset: ol; list-style: none}
.slide ol > li {counter-increment: ol}
.slide ol > li::before {/*float: left;*/ display: inline-block; width: 2em;
  margin-left: -2em; text-align: right; content: counter(ol) ".\A0"}
.slide ol > li > p:first-child {display: inline}
.slide ol[start="2"] {counter-reset: ol 1}
.slide ol[start="3"] {counter-reset: ol 2}
.slide ol[start="4"] {counter-reset: ol 3}
.slide ol[start="5"] {counter-reset: ol 4}
.slide ol[start="6"] {counter-reset: ol 5}
.slide ol[start="7"] {counter-reset: ol 6}
.slide ol[start] {counter-reset: ol calc(attr(start integer) - 1)}

/* Slides with an image on the left (.side) or right (.side.right) one third */
.slide.side {padding-left: 15.867rem /*= L + 1 + (w - L - 4) * 30% + 1 */}
.slide.side.right, .slide.side.r {padding-left: 6rem /*= L + 2 */;
  padding-right: 12.867rem; /*= 2 + (w - L - 4) * 30% + 1 */}
.side .side {position: absolute; top: 2em /* top margin */;
  left: 5rem /*= L + 1 */; height: 20rem /*= N - 3 */; object-fit: contain;
  width: 9.8667rem /*= (w - L - 4) * 30% */}
.side .side.cover {object-fit: cover; top: 0; left: 0; height: 23em /*= N */;
  width: 14.867em /*= (w - L - 4) * 30% + L + 1 */;
  border-radius: 0.5rem 0 0 0.5rem}
.side.right .side, .side.r .side {
  left: 29.022em /*= w - 2 - (w - L - 4) * 30% */}
.side.right .side.cover, .side.r .side.cover {border-radius: 0 0.5rem 0.5rem 0;
  width: 11.867em /*= (w - L - 4) * 30% + 2 */}

/* Slides with a big, square image of size N - 3em on the left or right */
.slide.side.big {padding-left: 26em /*= L + 1 + (N - 3) + 1 */}
.slide.side.right.big, .slide.side.r.big {padding-left: 6em /*= L + 2 */;
  padding-right: 22em /*= 1 + (N - 3) + 1 */}
.side.big .side {top: 2em; left: 5em /*= L + 1 */;
  height: 20em /*= N - 3 */; width: 20em /*= N - 3 */}
.side.big.right .side, .side.big.r .side {left: 19.889em /*= w - 1 - (N - 3) */}
.side.big .side.cover {object-fit: cover; top: 0; left: 0;
  height: 23em /*= N */; width: 25em /*= L + 1 + (N - 3) */}
.side.big.right .side.cover, .side.big.r .side.cover {
  left: 19.889em /*= w - 1 - (N - 3) */; width: 21em /*= (N - 3) + 1 */}

/* Cover pages */
.slide.cover {background:
    url(side-banner-fg.svg) 0 50% / auto 100% no-repeat,
    url(cover.svg) 50% 50% / 100% auto no-repeat, hsl(0,0%,98%);
  text-shadow: none; text-align: center; display: flex; flex-direction: column}
.slide.cover::after {background:
    content-box center / 2em 1.55em radial-gradient(circle closest-side,
      hsl(0,0%,30%), hsl(0,0%,30%) 100%, hsla(0,0%,30%,0) 100%,
      hsla(0,0%,30%,0)) no-repeat}
.cover address {order: -1; color: hsl(356,67%,35%)}
.cover h1 {margin-top: auto}
.cover p {color: #005a9c}

/* Last page */
.final h1, .final h2 {color: hsl(356,67%,40%)}

/* Notes in a smaller font */
.slide .note {font-size: 70%}

/* Miscellaneous styles */
.num {font-variant-numeric: oldstyle-nums tabular-nums diagonal-fractions}
.slide code, .slide pre {font-family: Andale Mono, Courier, monospace;
  text-shadow: none}
.slide code {background: #eee; padding: 0.1em 0.3em; border-radius: 0.3em}
sub, sup {line-height: 0.5}
.slide pre {padding: 0 0.2em; background: black; color: hsl(120,100%,70%);
  text-shadow: none}

/* Explicit placement on a 3x3 grid */
.place {position: absolute; box-sizing: border-box;
  max-width: 10.296rem; /*= (w - L - 6) / 3 */
  top: 12rem /*= 2 + (N - 3) / 2 */;
  left: 22.444rem; /*= L + 2 + (w - L - 4) / 2 */
  transform: translate(-50%, -50%); text-align: center}
.place.t, .place.top {top: 2rem; transform: translate(-50%,0)}
.place.b, .place.bottom {top: auto; bottom: 1rem; transform: translate(-50%,0)}
.place.l, .place.left {left: 6rem; /*= L + 2 */
  transform: translate(0,-50%); text-align: left}
.place.r, .place.right {left: auto; right: 2rem;
  transform: translate(0,-50%); text-align: right}
.place.t.l, .place.top.left, .place.t.r, .place.top.right, .place.b.l,
.place.bottom.left, .place.b.r, .place.bottom.right {transform: none}

/* Numbered lines in a PRE */
pre.numbered {padding-left: 2em; overflow-y: hidden; position: relative}
pre.numbered::before {color: #aaa; text-align: right; white-space: pre-line;
  text-shadow: none;
  content: "1\A 2\A 3\A 4\A 5\A 6\A 7\A 8\A 9\A 10\A 11\A 12\A 13\A 14\A 15\A 16\A 17\A 18\A 19\A 20";
  position: absolute; top: 0; left: 0; width: 1.2em; font-family: serif;
  border-right: thin solid; padding-right: 0.2em}

/* Full-size image overlays */
img.cover, img.fit {position: absolute; z-index: -1; top: 0; left: 0;
  border-radius: 0.5rem;
  width: 100%; height: 100%; object-fit: cover; padding: 0}
img.fit {object-fit: contain}

/* Banner on the left, slide number in lower right in a dark circle */
.slide::after {content: counter(slide); color: white; position: absolute;
  top: 0; right: 0; bottom: 0; left: 0; z-index: -1;
  padding: 20.45rem /*= N - 1 - 1.55 */ 0 1rem 38.889rem /*= w - 2 */;
  text-shadow: none; border-radius: 0.5rem;
  text-align: center; font: bold 1em/1.55 My Montserrat, sans-serif;
  background:
    0 50% / auto 100% no-repeat url(side-banner.svg),
    content-box center / 2em 1.55em radial-gradient(circle closest-side,
      hsl(0,0%,30%), hsl(0,0%,30%) 100%, hsla(0,0%,30%,0) 100%,
      hsla(0,0%,30%,0)) no-repeat}
.clear .slide::after, .slide.clear::after {content: none; background: none}

/* Two columns, and alternate elements in the left and right column */
.slide .columns > * {box-sizing: border-box;
  width: 47.134% /*= (w - L - 4)/2/(w - L - 2) */; float: right}
.slide .columns > *:nth-child(odd) {clear: both; float: left}
.slide .columns {overflow: hidden; line-height: 1.5 /* Reduced from 1.6 */}
.slide .columns > :nth-child(-n+2),
.slide .columns > :nth-child(-n+2) > :first-child {margin-top: 0}
@supports (display: grid) {
  .slide .columns {overflow: visible; display: grid; grid: "a  b" / 1fr 1fr;
    grid-gap: 0 2em; justify-items: normal}
  .slide .columns > * {width: auto}
}
@supports not (display: grid) {
  /* If grid is not supported and the column is a list, remove the margin */
  .slide .columns > li {margin-left: 0; list-style-position: inside}
}

/* A list as a tree structure with box-drawing characters */
.tree {list-style: none; font: 1em/1 monospace;
  white-space: nowrap; padding: 0.2em 0; overflow: auto}
.tree li::before {content: none}
.tree code {background: none; padding: 0;
  font-family: My Lato, Carlito, Calibri, Open Sans,
    Helvetica Neue, Helvetica, Arial, Liberation Sans, sans-serif}
.comment .tree code {font-family: serif}

/* A trick that may be useful for Jeff's slides: class "compact" can
   be set on a list or other container and removes the top and bottom
   margin from list items and paragraphs inside that container. */
.slide .compact li, .slide .compact p {margin-top: 0; margin-bottom: 0}

/* Striped tables */
table.striped {border-collapse: collapse; margin-bottom:0.48em; width: 100%}
table.striped td, table.striped th {padding: 0.15em 0.3em; font-size: 0.93em; text-align: left}
table.striped tr:nth-child(2n+2) {background: #EEE; text-shadow: none}

/* Takahashi method (very big text, very few words) */
.shout {font-size: 400%; line-height: 1.1}
p.shout {margin: 0.25em 0}

/* Figures, and images with collapsed descriptions  */
img {max-width: 100%;}
figure {text-align: center; margin: 0 0 0.6em 0}
figure img, summary img {display: block; margin: 0 auto 0.6em auto;
  max-height: 15.6em /*= N - 2 - 1.1 * 2 - 0.6 * 2 - 2 */}
.slide summary {list-style: none} /* Hide the triangle */
.slide summary::-webkit-details-marker {display: none} /* Ditto webkit/blink */
.slide [open] summary img {max-height: 4em}
.slide summary {outline: none}
.slide summary::before {content: "⊖"; float: left; width: 0.9em;
  margin-left: -1.1em; text-align: left; line-height: 0.9}
.slide [open] > summary::before {content: "⊕"}
.slide summary:focus::before {outline: thin solid blue;
  outline: thin solid invert}

/* Keyboard keys */
kbd {font-weight: bold; speak-as: spell-out}

/* The progress element is normally empty */
.progress {display: inline}

/* Notes between the slides */
.comment {background: black; color: white; padding: 1rem 1rem;
  font-family: Times New Roman, Times, serif; box-sizing: border-box;
  display: inline-block; border-radius: 0.5em; margin: 4em 2em 0 0;
  box-shadow: 0 0.4em 0.6em #000; vertical-align: bottom; overflow: auto}
.comment :link, .comment :visited {color: inherit; text-decoration: underline}
.comment pre {margin-left: 1em; font-family: Helvetica, sans-serif}
.comment :first-child {margin-top: 0}
.comment dd, .comment ul, .comment ol {padding-left: 1em; margin-left: 0}
.comment dd {margin-bottom: 1em}
.comment h1, .comment h2, .comment h3, .comment h4, .comment h5, .comment h6 {
  break-after: avoid}
.comment:before {content: "notes"; display: block;
  text-align: center; font-size: small; font-variant: small-caps;
  border-bottom: thin solid; padding-bottom: 0.3em; margin-bottom: 1rem}

/* Long comments */
.comment.long {/*columns: 25em; column-rule: thin solid; column-gap: 2rem;
  widows: 2; orphans: 2; width: auto;*/ height: auto; display: block;
  border-radius: 0; overflow: auto; /*margin: 1rem 1rem 2rem 0;*/
  background: white; color: black}
.comment.long:before {/*content: none*/}

/* Layout in slide mode (when body has class=full) */
.full {transform: scale(var(--shower-full-scale))} /* For Shower 3.1/3.2 */
.full, .full .slide {position: absolute; overflow: hidden}
.full {top: 50%; left: 50%; background: black;
  margin: -11.5em /*= -N/2 */ 0 0 -20.444em /*= -w/2 */}
.full .slide {visibility: hidden; top: 0; left: 0; margin: 0}
.full .slide.active {visibility: visible}
.full .comment {display: none}
.full .slide:target {outline: none}

.full .progress {position: absolute; top: 0; left: 0; height: 1px;
  background: linear-gradient(to right, hsla(0,100%,50%,0),hsla(0,100%,50%,1));
  z-index: 1}
@media not screen and (prefers-reduced-motion: reduce) {
  /* Experimental media query, see
     https://www.w3.org/TR/2020/WD-mediaqueries-5-20200731/ */
  .full .progress {transition: 0.5s}
}

.full .watermark {position: absolute; top: 50%; left: 50%; z-index: 1;
  margin: 0; transform: translate(-50%, -50%) rotate(-29deg)}

/* Incremental display with elements replacing each other. In index
   mode, the elements are side by side with a scroll bar to reach them
   (and scroll snap to make scrolling easier). In slide mode, all
   items are in the first slot, but at most one of them is visible. */
.incremental.in-place, .overlay.in-place {display: grid; grid: "a" / 100%;
  gap: 2em; grid-auto-columns: 100%; grid-auto-flow: column;
  overflow: auto; scrollbar-width: thin; scroll-snap-type: x mandatory}
.incremental.in-place > * {scroll-snap-align: end}
.full .incremental.in-place > *, .full .overlay.in-place > * {grid-area: a}
.full .incremental.in-place > .visited:not(.active):not(:last-child),
.full .overlay.in-place > .visited:not(.active):not(:last-child) {
  visibility: hidden}

/* Reveal elements one by one. (incremental/overlay only works with b6+) */
.full .incremental > :not(.active):not(.visited),
.full .overlay > :not(.active):not(.visited),
.full .next:not(.active):not(.visited) {visibility: hidden}

/* With class=greeked, elements aren't hidden, but shown as gray bars */
.full .incremental > .greeked:not(.active):not(.visited),
.full .incremental.greeked > :not(.active):not(.visited),
.full .greeked .incremental > :not(.active):not(.visited),
.full.greeked .incremental > :not(.active):not(.visited),
.full .overlay > .greeked:not(.active):not(.visited),
.full .overlay.greeked > :not(.active):not(.visited),
.full .greeked .overlay > :not(.active):not(.visited),
.full.greeked .overlay > :not(.active):not(.visited),
.full .next.greeked:not(.active):not(.visited),
.full .greeked .next:not(.active):not(.visited),
.full.greeked .next:not(.active):not(.visited) {visibility: inherit;
  text-shadow: none; background: hsl(0,0%,50%); color: transparent;
  speak: never}

/* With class=strong, the currently active element is red. */
.full .incremental .active.strong, .full .overlay .active.strong,
.full .incremental.strong .active, .full .overlay.strong .active,
.full .strong .incremental .active, .full .strong .overlay .active,
.full.strong .incremental .active, .full.strong .overlay .active,
.full .strong .next.active, .full .next.active.strong,
.full.strong .next.active {color: hsl(356,67%,40%)}

/* With class=dim, elements that are no longer active are grayed out. */
.full .incremental > .visited.dim,
.full .incremental.dim > .visited,
.full .dim .incremental > .visited,
.full.dim .incremental > .visited,
.full .overlay > .visited.dim,
.full .overlay.dim > .visited,
.full .dim .overlay > .visited,
.full.dim .overlay > .visited,
.full .next.visited.dim,
.full .dim .next.visited,
.full.dim .next.visited {opacity: 0.3}

/* Animate the active element when it appears. By default, the element
   is progressively revealed, starting from the left. Setting
   class=emerge instead causes the element to go from transparent to
   opaque. And class=quick omits the animation. The class can be set
   on the element itself or on any ancestor, including on BODY. .*/
@media not screen and (prefers-reduced-motion: reduce) {
  /* Experimental media query, see
     https://www.w3.org/TR/2020/WD-mediaqueries-5-20200731/ */
  .full .incremental > .active, .full .overlay > .active,
  .full .next.active {animation: unfold 1s}
  .full .incremental > .active.emerge, .full .overlay > .active.emerge,
  .full .incremental.emerge > .active, .full .overlay.emerge > .active,
  .full .emerge .incremental > .active, .full .emerge .overlay > .active,
  .full.emerge .incremental > .active, .full.emerge .overlay > .active,
  .full .emerge .next.active, .full .next.active.emerge,
  .full.emerge .next.active {animation: fade-in 0.5s}
  .full .incremental .active.quick, .full .overlay .active.quick,
  .full .incremental.quick .active, .full .overlay.quick .active,
  .full.quick .incremental .active, .full.quick .overlay .active,
  .full .quick .incremental .active, .full .quick .overlay .active,
  .full .quick .next.active, .full .next.active.quick,
  .full.quick .next.active {animation: none}
}

@keyframes unfold {
  from {clip-path: inset(0% 100% 0% -100%)}
  to {clip-path: inset(0% 0% 0% -100%)}
}

/* Outline elements on the second window that are incrementally
   displayed on the first window (b6+) */
.secondwindow .slide:target .incremental > *,
.secondwindow .slide:target .next {outline: solid 1px red}

/* Animation of a slowly growing element */
@media not screen and (prefers-reduced-motion: reduce) {
  /* Experimental media query, see
     https://www.w3.org/TR/2020/WD-mediaqueries-5-20200731/ */
  .full .grow {transition: 3s 1s ease-in-out transform;
    position: relative; transform: scale(0.1); transform-origin: 0 50%}
  .active .grow {transform: scale(1)}
}

/* Transitions between slides */
@media not screen and (prefers-reduced-motion: reduce) {
  /* Experimental media query, see
     https://www.w3.org/TR/2020/WD-mediaqueries-5-20200731/ */

  .full .slide.active ~ .visited {animation: none} /* Moving backwards */

  /* Transition: fade-in */
  .full .slide.fade-in.visited,
  .fade-in .slide.visited {animation: delay 1s 1}
  .full .slide.fade-in + .active,
  .full .slide.fade-in + .comment + .active,
  .fade-in .slide.active {animation: fade-in 1s 1}
  @keyframes delay {
    from {visibility: visible}
    to {visibility: visible}
  }
  @keyframes fade-in {
    from {opacity: 0}
    to {opacity: 1}
  }

  /* Transition: slide-in */
  .full .slide.slide-in.visited,
  .slide-in .slide.visited {animation: leftout 1s 1}
  .full .slide.slide-in + .active,
  .full .slide.slide-in + .comment + .active,
  .slide-in .slide.active {animation: leftin 1s 1}
  @keyframes leftout {
    from {transform: translate(0%, 0); visibility: visible; z-index: 1}
    to {transform: translate(-100%, 0); visibility: visible; z-index: 1}
  }
  @keyframes leftin {
    from {transform: translate(-100%, 0); visibility: visible}
    to {transform: translate(0%, 0); visibility: visible}
  }

  /* Transition: slide-out */
  .full .slide.slide-out.visited,
  .slide-out .slide.visited {animation: leftout 1s 1}
  .full .slide.slide-out + .active,
  .full .slide.slide-out + .comment + .active,
  .slide-out .slide.active {animation: do-nothing 1s 1}
  @keyframes do-nothing {
    from {z-index: 0}
    to {z-index: 0}
  }

  /* Transition: move-left */
  .full .slide.move-left.visited,
  .move-left .slide.visited {animation: leftout 1s 1}
  .full .slide.move-left + .active,
  .full .slide.move-left + .comment + .active,
  .move-left .slide.active {animation: rightin 1s 1}
  @keyframes rightin {
    from {transform: translate(100%, 0); visibility: visible}
    to {transform: translate(0%, 0); visibility: visible}
  }

  /* Transition: slide-up */
  .full .slide.slide-up.visited,
  .slide-up .slide.visited {animation: topout ease-in 1s 1}
  .full .slide.slide-up + .active,
  .full .slide.slide-up + .comment + .active,
  .slide-up .slide.active {animation: do-nothing ease-in 1s 1}
  @keyframes topout {
    from {transform: translate(0, 0%); visibility: visible; z-index: 1}
    80% {opacity: 1.0}
    to {transform: translate(0, -100%); visibility: visible; opacity: 0.0;
      z-index: 1}
  }
  /* Transition: move-up */
  .full .slide.move-up.visited,
  .move-up .slide.visited {animation: topout ease-in 1s 1}
  .full .slide.move-up + .active,
  .full .slide.move-up + .comment + .active,
  .move-up .slide.active {animation: bottomin ease-in 1s 1}
  @keyframes bottomin {
    from {transform: translate(0, 100%); visibility: visible}
    to {transform: translate(0, 0%); visibility: visible}
  }

  /* Transition: flip-up */
  .full {perspective: 1000px; perspective: 1000}
  .full .slide.flip-up.visited,
  .flip-up .slide.visited {animation: turn-down 1s 1 ease-in}
  .full .slide.flip-up + .active,
  .full .slide.flip-up + .comment + .active,
  .flip-up .slide.active {animation: turn-up 1s 1 ease-out}
  @keyframes turn-down {
    from {transform: rotateX(0deg); visibility: visible}
    50%, to {transform: rotateX(90deg); visibility: hidden}
  }
  @keyframes turn-up {
    from, 50% {transform: rotateX(-90deg); visibility: visible}
    to {transform: rotateX(0deg); visibility: visible}
  }

  /* Transition: flip-left */
  .full .slide.flip-left.visited,
  .flip-left .slide.visited {animation: flip-left1 1s 1 ease-in}
  .full .slide.flip-left + .active,
  .full .slide.flip-left + .comment + .active,
  .flip-left .slide.active {animation: flip-left2 1s 1 ease-out}
  @keyframes flip-left1 {
    from {transform: rotateY(0deg); visibility: visible}
    50%, to {transform: rotateY(-90deg); visibility: hidden}
  }
  @keyframes flip-left2 {
    from, 50% {transform: rotateY(90deg); visibility: visible}
    to {transform: rotateY(0deg); visibility: visible}
  }

  /* Transition: center-out */
  .full .slide.center-out.visited,
  .center-out .slide.visited {animation: gray 1s 1}
  .full .slide.center-out + .active,
  .full .slide.center-out + .comment + .active,
  .center-out .slide.active {animation: center-out 1s 1}
  @keyframes gray {
    from, to {opacity: 0.5; visibility: visible}
  }
  @keyframes center-out {
    from {clip-path: circle(0)}
    to {clip-path: circle(100%)}
  }

  /* Transition: wipe-left */
  .full .slide.wipe-left.visited,
  .wipe-left .slide.visited {animation: gray 1s 1}
  .full .slide.wipe-left + .active,
  .full .slide.wipe-left + .comment + .active,
  .wipe-left .slide.active {animation: rightin 1s 1}

  /* Transition: zigzag-left */
  .full .slide.zigzag-left.visited,
  .zigzag-left .slide.visited {animation: gray 1s 1}
  .full .slide.zigzag-left + .active,
  .full .slide.zigzag-left + .comment + .active,
  .zigzag-left .slide.active {animation: zigzag-left 1s 1}
  @keyframes zigzag-left {
    from {clip-path:
      polygon(120% 0%, 120% 0%, 100% 30%, 120% 60%, 110% 100%, 120% 100%)}
    to   {clip-path:
      polygon(120% 0%,   0% 0%, -20% 30%,   0% 60%, -10% 100%, 120% 100%)}
  }

  /* Transition: zigzag-right */
  .full .slide.zigzag-right.visited,
  .zigzag-right .slide.visited {animation: gray 1s 1}
  .full .slide.zigzag-right + .active,
  .full .slide.zigzag-right + .comment + .active,
  .zigzag-right .slide.active {animation: zigzag-right 1s 1}
  @keyframes zigzag-right {
    from {clip-path:
      polygon(-20% 0%,  -20% 0%, 0% 30%,  -20% 60%, -10% 100%, -20% 100%)}
    to   {clip-path:
      polygon(-20% 0%, 100% 0%, 120% 30%, 100% 60%, 110% 100%, -20% 100%)}
  }

  /* Transition: cut-in */
  .full .slide.cut-in.visited,
  .cut-in .slide.visited {animation: gray 1s 1}
  .full .slide.cut-in + .active,
  .full .slide.cut-in + .comment + .active,
  .cut-in .slide.active {animation: cut-in 1s 1}
  @keyframes cut-in {
    from {transform: translate(-100%, -100%)}
    to {transform: translate(0%, 0%)}
  }

} /* End of @media not screen and (prefers-reduced-motion: reduce) */

/* A section with aria-live=assertive, which should be spoken, but not
   displayed. (b6+ adds this style by itself, but Shower relies on the
   style sheet setting it.)*/
[role=region][aria-live=assertive] {position: absolute; top: 0; left: 0;
  clip: rect(0 0 0 0)}

/* Trick: If the viewport is exactly w x h or 1.2w x 1.2h,
   it means the slides are
   being shown inside an iframe of that size. Hide everything except
   the targeted slide in that case and omit the black background,
   which would otherwise be visible around the rounded corner of the
   slide. (When JavaScript is on, adding ?full to the end of the slide
   URL, e.g., ".../myslides.html?full#intro", has a similar effect and
   doesn't require the iframe to be this exact size.) */
@media (min-width: 40.839em /*= w - 0.05 */) and
    (max-width: 40.939em /*= w + 0.05 */) and
    (min-height: 22.95em /*= N - 0.05 */) and
    (max-height: 23.05em /*= N + 0.05 */),
    (min-width: 49.017em /*= 1.2 * w - 0.05 */) and
    (max-width: 49.117em /*= 1.2 * w + 0.05 */) and
    (min-height: 27.55em /*= 1.2 * N - 0.05 */) and
    (max-height: 27.65em /*= 1.2 * N + 0.05 */) {
  html {font-size: calc(100vh / 23)}
  body {margin: 0; overflow: hidden}
  body, .full {background: transparent}
  body > *, .slide {display: none}
  .slide {box-shadow: none; margin: 0}
  .slide:target {display: block; outline: none}
}

/* class=framed is used to indicate the slides are inside an iframe. */
body.framed {background: transparent}
body.framed .slide {box-shadow: none}
body.framed .progress {display: none}

/* class=secondwindow indicates this is a control window for another. (b6+) */
body.secondwindow {background: #300}
body.secondwindow .slide:target {outline-color: yellow}
body.secondwindow .comment {background: black; color: white; box-shadow: none;
  height: auto; max-height: 23rem /*= N */}

/* Style for clocks on the second window or in index mode. */
body {--time-factor: 0} /* Make sure it is defined, will be set by b6+ */
.fullclock, .clock {position: fixed; z-index: 1; top: 0.5em; right: 0.5em;
  background: linear-gradient(hsl(120,90%,20%),
    hsl(120,80%,25%), hsl(120,90%,19%)); color: #fff; border-radius: 0.5em;
  box-shadow: 1px 2px 3px #000; text-align: center; width: fit-content}
.fullclock {padding: 0.3em; display: grid; justify-items: center; gap: 0.1em;
  grid: "x   y   z" auto
  	"a   b   d" auto
        "f   c   e" auto
	"h   c   g" auto
	/ 1fr 1fr 1fr}
.fullclock time:nth-of-type(1) {grid-area: a; color: #9F9}
.fullclock time:nth-of-type(2) {grid-area: b}
.fullclock time:nth-of-type(3) {grid-area: d}
.fullclock .timepause {grid-area: g}
.fullclock .timeinc {grid-area: e}
.fullclock .timedec {grid-area: f}
.fullclock .timereset {grid-area: h}
.fullclock i:nth-of-type(1) {grid-area: x}
.fullclock i:nth-of-type(2) {grid-area: y}
.fullclock i:nth-of-type(3) {grid-area: z}
.fullclock > span {grid-area: c}
.fullclock time {padding: 0 0.3em}
.fullclock time b {font-family: OCR A Std, Orator Std, monospace;
  font-size: 1.2em}
.fullclock i {font-size: 70%; font-style: normal; color: #9F9}
.fullclock button {width: 100%; font-family: Noto Sans Symbols, sans-serif}
/* The span is made into a pie chart that shows the fraction of time used. */
.fullclock > span, .clock > span {display: inline-block;
  width: 3.5em; height: 3.5em; border-radius: 50%; background: #FFF;
  background: conic-gradient(
      #000 calc(var(--time-factor) * 360deg),
      #FFF calc(var(--time-factor) * 360deg),
      #FFF 360deg), #FFF}
@supports not (background: conic-gradient(
		   #000 calc(var(--time-factor) * 360deg),
		   #FFF calc(var(--time-factor) * 360deg),
		   #FFF 360deg), #FFF) {
  /* If pie chart not possible, show a clock hand that turns */
  .fullclock > span, .clock > span {position: relative; background: #FFF}
  .fullclock > span > span, .clock > span > span {height: 2px;
    width: 50%; background: #000; position: absolute; top: calc(50% - 1px);
    left: 50%; transform-origin: 0 1px;
    transform: rotate(calc(var(--time-factor) * 360deg - 90deg))}
}
.clock {padding: 0.3em; display: grid; justify-items: center; gap: 0.1em;
  grid: "a   a   a   a" auto
        "c   c   e   f" auto
	"c   c   g   h" auto
       / 1fr 1fr 1fr 1fr}
.clock time {grid-area: a; padding: 0 0.3em}
.clock .timepause {grid-area: g}
.clock .timedec {grid-area: e}
.clock .timeinc {grid-area: f}
.clock .timereset {grid-area: h}
.clock > span {grid-area: c}
.clock time b {font-family: OCR A Std, Orator Std, monospace;
  font-size: 1.2em}
.clock button {width: 100%; font-family: Noto Sans Symbols, sans-serif}

/* When time is nearly up, make the clock orange. */
body.time-warning .fullclock, body.time-warning .clock {background:
  linear-gradient(hsl(33,100%,37%), hsl(33,90%,42%), hsl(33,100%,36%))}
/* When time is up, make the clock red. */
body[data-time-factor="100"] .fullclock,
body[data-time-factor="100"] .clock {background:
  linear-gradient(hsl(0,100%,47%), hsl(0,90%,55%), hsl(0,100%,46%))}

/* Make the clock blue when it is paused. */
body.paused .fullclock, body.paused .clock {
  background: linear-gradient(hsl(240,85%,55%), hsl(240,80%,60%),
    hsl(240,85%,54%))}
body:not(.paused) .timepause :nth-child(1) {display: none}
body.paused .timepause :nth-child(2) {display: none}
body.paused .timepause {opacity: 0.7}

/* Dark mode swaps uses white-on-black text and darker banner images.
   TODO: Also change the color of incremental elements with class=strong. */
@media (prefers-color-scheme: dark) {
  .slide {color: white; background-color: black;
    text-shadow: 0 -1px #000, 1px 0 #000,
      0 1px #000, -1px 0 #000,
      -0.7px -0.7px #000, 0.7px -0.7px #000,
      0.7px 0.7px #000, -0.7px 0.7px #000}
  .slide::after {background:
      0 50% / auto 100% no-repeat url(side-banner-dark.svg),
      content-box center / 2em 1.55em radial-gradient(circle closest-side,
	hsl(0,0%,30%), hsl(0,0%,30%) 100%, hsla(0,0%,30%,0) 100%,
	hsla(0,0%,30%,0)) no-repeat}
  .slide.cover {background:
      url(side-banner-fg-dark.svg) 0 50% / auto 100% no-repeat,
      url(cover-dark.svg) 50% 50% / 100% auto no-repeat, hsl(0,0%,98%);
    text-shadow: none}
  .cover address {color: hsl(62,100%,60%)}
  .cover p {color: hsl(205, 100%, 90%)}
  .final h1, .final h2 {color: hsl(62,100%,60%)}
  .slide address {color: hsl(62,100%,60%)}
  .slide code {background: #444}
  .slide :link {color: inherit; background: hsla(240,100%,20%,0.3)}
  .slide :visited {color: inherit; background: hsla(270,100%,20%,0.3)}
  .slide :link, .slide :visited {padding: 0.1em 0.3em; border-radius: 0.3em}
  .slide em {background: hsl(322,100%,40%)}
  .slide h3 {color: hsl(62,100%,60%)}
  table.striped tr:nth-child(2n+2) {background: #333}
  .comment.long {background: #333; color: white}
}

/* class=white gives a slide white-on-black text, independent of dark
   mode. (But it does not change the banner images.) */
.white {color: white; background-color: black;
  text-shadow: 0 -1px #000, 1px 0 #000,
    0 1px #000, -1px 0 #000,
    -0.7px -0.7px #000, 0.7px -0.7px #000,
    0.7px 0.7px #000, -0.7px 0.7px #000}
.white.cover {text-shadow: none}
.white.cover h1 {color: black}
.white address {color: hsl(356,90%,60%)}
.white.cover address {color: hsl(356,67%,35%)}
.white.final h1, .white.final h2 {color: hsl(62,100%,60%)}
.white code {background: #444}
.white :link {color: inherit; background: hsla(240,100%,20%,0.3)}
.white :visited {color: inherit; background: hsla(270,100%,20%,0.3)}
.white :link, .white :visited {padding: 0.1em 0.3em; border-radius: 0.3em}
.white em {background: hsl(322,100%,40%)}
.white h3 {color: hsl(62,100%,60%)}
.white table.striped tr:nth-child(2n+2) {background: #333}

/* class=black gives a slide black-on-white text, independent of dark
   mode. (But it does not change the banner images.) */
.black {color: black; background-color: hsl(0,0%,98%);
  text-shadow: 0 -1px hsl(0,0%,98%), 1px 0 hsl(0,0%,98%),
    0 1px hsl(0,0%,98%), -1px 0 hsl(0,0%,98%),
    -0.7px -0.7px hsl(0,0%,98%), 0.7px -0.7px hsl(0,0%,98%),
    0.7px 0.7px hsl(0,0%,98%), -0.7px 0.7px hsl(0,0%,98%)}
.black.cover {text-shadow: none}
.black address {color: hsl(356,67%,40%)}
.black.cover address {color: hsl(356,67%,35%)}
.black.final h1, .black.final h2 {color: hsl(356,67%,40%)}
.black code {background: #eee}
.black :link {color: #00e; color: linktext; background: none}
.black :visited {color: #609; color: visitedtext; background: none}
.black :link, .black :visited {padding: initial; border-radius: initial}
.black em {background: hsl(62,100%,50%)}
.black h3 {color: hsl(356,67%,40%)}
.black table.striped tr:nth-child(2n+2) {background: #EEE}

/* Printing. */
@page {
  margin: 1cm;
  @bottom {content: counter(page)}
}
@media print {
  html {font-size: 10pt}
  body {background: none; color: black; margin: 0; columns: 40.889em /*= w */;
    column-gap: 4em; column-rule: 0.2pt solid}
  .slide {border: 0.2pt solid black; margin: 2em auto; display: block;
    border-radius: 0;
    overflow: hidden; break-inside: avoid; box-shadow: none}
  .comment {background: none; color: black; padding: 0;
    columns: 25em; column-rule: thin solid; column-gap: 2rem;
    widows: 2; orphans: 2; width: auto; height: auto; display: block;
    border-radius: 0; overflow: auto;
    margin: 2rem 1rem 2rem 0; box-shadow: none}
  .comment:before {content: none}
  .slide summary::before {content: none}
  .slide details {visibility: hidden}
  .slide summary {visibility: visible}
  [role=region][aria-live=assertive] {display: none}
}

/* Output to PDF (trick).

   To output to PDF, print the slides to PDF while selecting a
   landscape paper size, e.g. A4 landscape or Letter landscape.

   This style sheet assumes that, when the output is in landscape
   mode, the goal is to export one slide per page, without margins,
   and omitting the comments between the slides. (On the other hand,
   to output multiple slides per page and interleave the comments,
   choose a page size in portrait mode.)

   Note: Not all user agents respect the 'size' property to set the
   size of the output. If they don't, there will be some margin
   to the right and below each slide. Prince respects the property.
   E.g, to make myslides.pdf from myslides.html:

     prince --page-size=landscape myslides.html

   W3C team can also use the ",pdfui" tool online.
*/
@media print and (orientation: landscape) {
  html {font-size: 7mm}
  .comment, .comment.long {display: none}
  .slide {margin: 0; page-break-after: always; box-shadow: none; border: none}

  @page {
    size: 286.22mm /*= 7 * w */ 161mm /*= 7 * N */;
    margin: 0;
    @bottom {content: none}
  }
}
@media print and (orientation: landscape) and (min-width: 11in) {
  /* Letter-size paper */
  html {font-size: 0.26902in /*= 11 / w */}
  @page {size: 11in 6.1875in /*= 11 / A */}
}
@media print and (orientation: landscape) and (min-width: 296mm) {
  /* A4-size paper */
  html {font-size: 7.2636mm /*= 297 / w */}
  @page {size: 297mm 167.06mm /*= 297 / A */}
}