/*
 * The look of the deck. Structure borrowed from Matt Godbolt's newer talks
 * (hrt-theme.css in github.com/mattgodbolt/what-happens-beneath-accu-2026):
 * every slide on a rounded panel, IBM Plex Sans with thin h1 and bold accent
 * h2, IBM Plex Mono code, accent-coloured list markers, links and progress
 * bar, glowing highlighted code lines.
 *
 * Made our own: a light palette (his is near-black; change it in :root
 * below), and his "thread" corner motif becomes a chain of nodes and links,
 * an AS path. Code blocks and byte dumps stay dark on the light page so the
 * monokai colours and the byte palette keep working.
 *
 * Try accents without editing:  index.html?accent=green  (blue, green,
 * amber, magenta). Make one permanent by copying its values into :root.
 */
@import url("https://fonts.googleapis.com/css2?family=IBM+Plex+Sans:ital,wght@0,300;0,400;0,500;0,700;1,300;1,400;1,500;1,700&family=IBM+Plex+Mono:ital,wght@0,400;0,500;1,400&display=swap");

:root {
  --ground: #e9edf5; /* behind the panels */
  --panel: #ffffff; /* the slide itself */
  --panel-edge: rgba(31, 111, 235, 0.22);
  --ink: #1f2333; /* body text */
  --ink-strong: #0b0d17; /* h1, h3 */
  --muted: #6b7088; /* h4, captions */
  --rule: #c3c8d8; /* table rules, borders */
  --accent: #1f6feb; /* h2, markers, links, motif */
  --accent-soft: #0b4ea2; /* inline code, emphasis */
  --accent-rgb: 31, 111, 235;
  /* Code blocks and byte dumps keep a dark ground of their own. */
  --code-ground: #1b1e33;
  --code-ink: #eceff9;
  --r-code-font: "IBM Plex Mono", "SF Mono", Menlo, Consolas, monospace;
  --r-heading-text-shadow: none;
}

:root[data-accent="green"] {
  --accent: #1a8a4f;
  --accent-soft: #0f6238;
  --accent-rgb: 26, 138, 79;
  --panel-edge: rgba(26, 138, 79, 0.22);
}

:root[data-accent="amber"] {
  --accent: #b86e00;
  --accent-soft: #7a4a00;
  --accent-rgb: 184, 110, 0;
  --panel-edge: rgba(184, 110, 0, 0.22);
}

:root[data-accent="magenta"] {
  --accent: #c2277f;
  --accent-soft: #8a1a5a;
  --accent-rgb: 194, 39, 127;
  --panel-edge: rgba(194, 39, 127, 0.22);
}

/* ---- ground and panels ---------------------------------------------------- */

.reveal-viewport {
  background: var(--ground);
}

.reveal {
  font-family: "IBM Plex Sans", "Helvetica Neue", Arial, sans-serif;
  font-size: 40px;
  font-weight: 400;
  color: var(--ink);
}

.reveal .slides section:not(.stack):not(.title-slide):not(.bare) {
  background-color: var(--panel);
  border-radius: 12px;
  box-shadow: 0 4px 30px rgba(20, 30, 60, 0.1);
  border: 1px solid var(--panel-edge);
  padding: 1em 0.8em;
  box-sizing: border-box;
}

/* ---- type ------------------------------------------------------------------ */

.reveal h1,
.reveal h2,
.reveal h3,
.reveal h4 {
  font-family: inherit;
  text-transform: none;
  text-shadow: none;
  margin: 0 0 20px 0;
  line-height: 1.25;
}

.reveal h1 {
  font-weight: 300;
  color: var(--ink-strong);
  font-size: 2.2em;
  line-height: 1.15;
}

.reveal h2 {
  font-weight: 700;
  color: var(--accent);
  font-size: 1.5em;
}

.reveal h3 {
  font-weight: 500;
  color: var(--ink-strong);
  font-size: 1.2em;
}

.reveal h4 {
  font-weight: 500;
  color: var(--muted);
  font-size: 1em;
}

.reveal p {
  margin: 20px 0;
  line-height: 1.5;
}

.reveal strong,
.reveal b {
  font-weight: 700;
  color: var(--ink-strong);
}

.reveal em {
  font-style: italic;
  color: var(--accent-soft);
}

.reveal a {
  color: var(--accent);
  text-decoration: none;
  transition: color 0.15s ease;
}

.reveal a:hover {
  color: var(--accent-soft);
}

.reveal ul,
.reveal ol {
  display: inline-block;
  text-align: left;
  margin: 0 0 0 1em;
}

.reveal ul {
  list-style-type: square;
}

.reveal ul li,
.reveal ol li {
  margin-bottom: 0.4em;
}

.reveal li::marker {
  color: var(--accent);
}

.reveal blockquote {
  background: var(--ground);
  border-left: 4px solid var(--accent);
  padding: 20px 30px;
  font-style: italic;
  width: 85%;
  margin: 20px auto;
  text-align: left;
}

.reveal img,
.reveal video,
.reveal iframe {
  max-width: 95%;
  max-height: 95%;
}

.reveal kbd {
  font-family: var(--r-code-font);
  font-size: 80%;
  border: 1px solid var(--rule);
  border-bottom-width: 3px;
  border-radius: 5px;
  padding: 0 0.35em;
}

/* ---- code ------------------------------------------------------------------ */

.reveal pre {
  width: 100%;
  margin: 20px auto;
  box-shadow: none;
  text-align: left;
  position: relative;
  font-size: 0.55em;
  line-height: 1.4;
}

.reveal code {
  font-family: var(--r-code-font);
  color: var(--accent-soft);
}

.reveal :not(pre) > code {
  white-space: nowrap;
  font-size: 92%;
}

.reveal pre code {
  display: block;
  color: var(--code-ink);
  background: var(--code-ground);
  border-radius: 6px;
  padding: 15px 20px;
  max-height: 560px;
  overflow: auto;
}

/* The lines being talked about glow; the rest dim (reveal handles the dim). */
.reveal .hljs.has-highlights tr.highlight-line {
  text-shadow:
    0 0 6px currentColor,
    0 0 12px currentColor;
  transition: text-shadow 0.4s ease;
}

/* ---- tables ---------------------------------------------------------------- */

.reveal table {
  border-collapse: collapse;
  border-spacing: 0;
  margin: 20px auto;
  font-size: 75%;
}

.reveal table th {
  font-weight: 700;
  color: var(--ink-strong);
}

.reveal table th,
.reveal table td {
  text-align: left;
  border-bottom: 1px solid var(--rule);
  padding: 0.25em 0.6em;
}

.reveal table tr:last-child td {
  border-bottom: none;
}

/* ---- reveal chrome ---------------------------------------------------------- */

.reveal .controls {
  color: var(--accent);
  bottom: 40px;
}

.reveal .progress {
  background: var(--panel);
  height: 4px;
}

.reveal .progress span {
  background: var(--accent);
  transition: width 800ms cubic-bezier(0.26, 0.86, 0.44, 0.985);
}

.reveal .slide-number {
  color: #fff;
  font-family: var(--r-code-font);
  font-size: 18px;
  font-weight: 500;
  background: rgba(var(--accent-rgb), 0.9);
  padding: 3px 9px;
  border-radius: 4px;
  right: 16px;
  bottom: 16px;
}

::selection {
  color: #fff;
  background: var(--accent);
}

/* ---- the path motif ---------------------------------------------------------
 * Matt's decks carry a ring with a line running off the edge. Ours is a short
 * AS path: nodes joined by links, heading off the top-right corner, mirrored
 * running up from the bottom-left. Drawn in the accent colour via a mask, so
 * it follows --accent. Hidden on the title slide and on "bare" slides.
 */
.reveal::before,
.reveal-viewport::before {
  content: "";
  position: fixed;
  background: var(--accent);
  z-index: 0;
  pointer-events: none;
  opacity: 0.9;
}

.reveal::before {
  top: 26px;
  right: 0;
  width: 38vw;
  height: 22px;
  -webkit-mask:
    url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 190 22'><g fill='none' stroke='black' stroke-width='3'><circle cx='11' cy='11' r='8'/><line x1='19' y1='11' x2='67' y2='11'/><circle cx='75' cy='11' r='8'/><line x1='83' y1='11' x2='131' y2='11'/><circle cx='139' cy='11' r='8'/><line x1='147' y1='11' x2='190' y2='11'/></g></svg>")
      left center / 190px 22px no-repeat,
    linear-gradient(black, black) 189px center / calc(100% - 189px) 3px no-repeat;
  mask:
    url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 190 22'><g fill='none' stroke='black' stroke-width='3'><circle cx='11' cy='11' r='8'/><line x1='19' y1='11' x2='67' y2='11'/><circle cx='75' cy='11' r='8'/><line x1='83' y1='11' x2='131' y2='11'/><circle cx='139' cy='11' r='8'/><line x1='147' y1='11' x2='190' y2='11'/></g></svg>")
      left center / 190px 22px no-repeat,
    linear-gradient(black, black) 189px center / calc(100% - 189px) 3px no-repeat;
}

.reveal-viewport::before {
  bottom: 64px;
  left: 40px;
  width: 22px;
  height: 36vh;
  -webkit-mask:
    url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 22 126'><g fill='none' stroke='black' stroke-width='3'><circle cx='11' cy='115' r='8'/><line x1='11' y1='107' x2='11' y2='59'/><circle cx='11' cy='51' r='8'/><line x1='11' y1='43' x2='11' y2='0'/></g></svg>")
      center bottom / 22px 126px no-repeat,
    linear-gradient(black, black) center top / 3px calc(100% - 125px) no-repeat;
  mask:
    url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 22 126'><g fill='none' stroke='black' stroke-width='3'><circle cx='11' cy='115' r='8'/><line x1='11' y1='107' x2='11' y2='59'/><circle cx='11' cy='51' r='8'/><line x1='11' y1='43' x2='11' y2='0'/></g></svg>")
      center bottom / 22px 126px no-repeat,
    linear-gradient(black, black) center top / 3px calc(100% - 125px) no-repeat;
}

.reveal:has(> .slides > section.title-slide.present)::before,
.reveal:has(> .slides section.bare.present)::before {
  display: none;
}

.reveal-viewport:has(.reveal > .slides > section.title-slide.present)::before,
.reveal-viewport:has(.reveal > .slides section.bare.present)::before {
  display: none;
}

.reveal:has(section.title-slide.present) .controls {
  display: none !important;
}

/* ---- wordmark, where his logo sits ------------------------------------------ */

.wordmark {
  position: fixed;
  left: 22px;
  bottom: 18px;
  z-index: 10;
  font-family: var(--r-code-font);
  font-size: 15px;
  letter-spacing: 0.04em;
  color: var(--muted);
  pointer-events: none;
}

.wordmark b {
  color: var(--accent);
  font-weight: 500;
}

.reveal:has(section.title-slide.present) ~ .wordmark,
.reveal:has(section.bare.present) ~ .wordmark {
  display: none;
}

/* ---- title slide -------------------------------------------------------------- */

.reveal section.title-slide {
  text-align: left;
  padding: 0 1.5em;
}

.reveal section.title-slide h1 {
  font-size: 2.6em;
  margin-bottom: 0.15em;
}

.reveal section.title-slide h3 {
  font-weight: 400;
  color: var(--accent);
  margin-bottom: 2.2em;
}

.reveal section.title-slide .byline {
  font-size: 60%;
  color: var(--muted);
  margin: 0;
}

/* ---- shown by index.html when the deck cannot start --------------------------- */

#deck-help {
  position: fixed;
  inset: 0;
  z-index: 100;
  padding: 8vh 10vw;
  background: var(--ground);
  color: var(--ink);
  font: 20px/1.5 "IBM Plex Sans", "Helvetica Neue", Arial, sans-serif;
}

#deck-help h2 {
  color: var(--accent);
  font-weight: 700;
}

#deck-help pre,
#deck-help code {
  font-family: var(--r-code-font);
  color: var(--accent-soft);
}

#deck-help pre {
  background: var(--panel);
  padding: 12px 16px;
  border-radius: 6px;
}

/* ---- print ------------------------------------------------------------------ */

html.print-pdf .wordmark,
html.reveal-print .wordmark {
  display: none;
}