/**
 * Signature Theme for reveal.js
 * IBM Plex · 5-color gradient identity · card-based layouts
 *
 * Key concept: every container (callout, card, grid cell) sets
 * --local-accent on itself. All h2/h3/h4 inside read that variable,
 * so heading color follows the container color automatically.
 */

@import url('https://fonts.googleapis.com/css2?family=IBM+Plex+Sans:ital,wght@0,300;0,400;0,600;1,300;1,400;1,600&family=IBM+Plex+Mono:wght@400;600&display=swap');

/* =============================================
   GLOBAL COLOR TOKENS
   ============================================= */
:root {
  --sig-1: #544b9a;   /* purple  */
  --sig-2: #8f70af;   /* violet  */
  --sig-3: #f0889e;   /* pink    */
  --sig-4: #12b3b2;   /* teal    */
  --sig-5: #7ec291;   /* green   */

  --bg:         #f7f8fb;
  --card:       #ffffff;
  --text:       #111111;
  --text-muted: #6b7280;
  --border:     #e6e9ef;

  /* Slide-level default accent — h2/h3/h4 fall back here */
  --local-accent: var(--sig-1);

  --gradient: linear-gradient(
    90deg,
    var(--sig-1)  0%  20%,
    var(--sig-2) 20%  40%,
    var(--sig-3) 40%  60%,
    var(--sig-4) 60%  80%,
    var(--sig-5) 80% 100%
  );
}

/* =============================================
   REVEAL CORE VARIABLES
   ============================================= */
:root {
  --r-background-color:           var(--bg);
  --r-main-font:                  'IBM Plex Sans', sans-serif;
  --r-main-font-size:             24px;
  --r-main-color:                 var(--text);
  --r-heading-font:               'IBM Plex Sans', sans-serif;
  --r-heading-color:              var(--text);
  --r-heading-font-weight:        600;
  --r-heading-line-height:        1.2;
  --r-heading-letter-spacing:     -0.01em;
  --r-heading-text-transform:     none;
  --r-heading-text-shadow:        none;
  --r-heading1-size:              2.6em;
  --r-heading2-size:              1.6em;
  --r-heading3-size:              1.2em;
  --r-heading4-size:              1em;
  --r-block-margin:               16px;
  --r-heading-margin:             0 0 16px 0;
  --r-code-font:                  'IBM Plex Mono', monospace;
  --r-link-color:                 var(--sig-4);
  --r-link-color-hover:           var(--sig-3);
  --r-selection-background-color: var(--sig-1);
  --r-selection-color:            #ffffff;
  --border-width: 8px;
}

/* =============================================
   SLIDE BACKGROUND + SIGNATURE BAR
   ============================================= */
.reveal-viewport,
.reveal .slide-background {
  background: var(--bg);
}

/* 6px gradient bar at top of every slide */
/*.reveal .slides section::before {
  content: '';
  position: absolute;
  top: 0;
  left: -9999px;
  right: -9999px;
  height: 6px;
  background: var(--gradient);
  pointer-events: none;
  z-index: 10;
}*/

/* =============================================
   BASE
   ============================================= */
.reveal {
  font-family: var(--r-main-font);
  font-size: var(--r-main-font-size);
  font-weight: 400;
  color: var(--r-main-color);
}

.reveal ::selection {
  color: var(--r-selection-color);
  background: var(--r-selection-background-color);
  text-shadow: none;
}

.reveal .slides section,
.reveal .slides section > section {
  line-height: 1.5;
  font-weight: inherit;
  text-align: left;
  padding: 44px 54px 36px;
  box-sizing: border-box;
  /* set slide-level default local-accent */
  --local-accent: var(--sig-1);
}

/* =============================================
   HEADINGS
   h2/h3/h4 all read --local-accent, which
   cascades from whichever container they sit in:
   slide → card → callout. No extra rules needed.
   ============================================= */
.reveal h1,
.reveal h2,
.reveal h3,
.reveal h4,
.reveal h5,
.reveal h6 {
  margin: var(--r-heading-margin);
  font-family: var(--r-heading-font);
  font-weight: var(--r-heading-font-weight);
  font-style: italic;
  line-height: var(--r-heading-line-height);
  letter-spacing: var(--r-heading-letter-spacing);
  text-transform: none;
  text-shadow: none;
  word-wrap: break-word;
}

.reveal h2,
.reveal h3,
.reveal h4,
.reveal h5,
.reveal h6 {
	width: 100%;
  text-align: left;
}


/* h1: always dark, big statement */
.reveal h1 { font-size: var(--r-heading1-size); color: var(--text); }

/* h2/h3/h4: pick up nearest --local-accent */
.reveal h2 { font-size: var(--r-heading2-size); color: var(--local-accent); }
.reveal h3 { font-size: var(--r-heading3-size); color: var(--local-accent); opacity: 0.85; }
.reveal h4 { font-size: var(--r-heading4-size); color: var(--local-accent); opacity: 0.7; }

/* =============================================
   TEXT UTILITIES
   ============================================= */
.reveal p { margin: var(--r-block-margin) 0; line-height: 1.6; color: #333; }
.reveal strong, .reveal b { font-weight: 700; }
.reveal em { font-style: italic; }

.reveal small {
  display: inline-block;
  font-size: 0.65em;
  line-height: 1.3em;
  color: var(--text-muted);
  vertical-align: top;
}

.reveal .muted    { color: var(--text-muted); }
.reveal .hl-teal  { color: var(--sig-4); font-weight: 600; }
.reveal .hl-purple{ color: var(--sig-1); font-weight: 600; }
.reveal .hl-pink  { color: var(--sig-3); font-weight: 600; }
.reveal .hl-green { color: var(--sig-5); font-weight: 600; }

/* =============================================
   LINKS
   ============================================= */
.reveal a {
  color: var(--r-link-color);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color 0.15s ease, border-color 0.15s ease;
}
.reveal a:hover {
  color: var(--r-link-color-hover);
  border-bottom-color: var(--r-link-color-hover);
}

/* =============================================
   LISTS
   ============================================= */
.reveal ol, .reveal ul {
  display: inline-block;
  text-align: left;
  margin: 0 0 0 0.2em;
}
.reveal ul           { list-style-type: disc; }
.reveal ol           { list-style-type: decimal; }
.reveal ul ul        { list-style-type: circle; }
.reveal ul ul ul     { list-style-type: square; }
.reveal ul ul, .reveal ul ol,
.reveal ol ol, .reveal ol ul { display: block; margin-left: 2em; }
.reveal li { padding-bottom: 0.4em; line-height: 1.5; }

.reveal ul.check { list-style: none; margin-left: 0; padding-left: 0; }
.reveal ul.check li::before { content: '✓'; color: var(--sig-5); font-weight: bold; margin-right: 0.5em; }
.reveal ul.cross { list-style: none; margin-left: 0; padding-left: 0; }
.reveal ul.cross li::before { content: '✗'; color: var(--sig-3); font-weight: bold; margin-right: 0.5em; }

/* =============================================
   BLOCKQUOTE
   Left border uses --local-accent so it adapts
   when inside a card or callout.
   ============================================= */
.reveal blockquote {
  display: block;
  position: relative;
  width: 80%;
  margin: var(--r-block-margin) auto;
  padding: 22px 28px;
  background: var(--card);
  border: 1px solid var(--border);
  border-left: var(--border-width) solid var(--local-accent);
  border-radius: 8px;
  box-shadow: 0 2px 12px rgba(0,0,0,0.06);
  font-style: italic;
  color: #444;
}
.reveal blockquote p { margin: 0; display: inline-block; color: inherit; }

/* =============================================
   CODE
   ============================================= */
.reveal code {
  font-family: var(--r-code-font);
  font-size: 0.86em;
  background: rgba(84,75,154,0.08);
  color: var(--sig-1);
  padding: 0.1em 0.35em;
  border-radius: 4px;
}

.reveal pre {
  display: block;
  position: relative;
  width: 90%;
  margin: var(--r-block-margin) auto;
  text-align: left;
  font-size: 0.56em;
  font-family: var(--r-code-font);
  line-height: 1.5em;
  background: #1e1e1e;
  border-radius: 8px;
  box-shadow: 0 4px 24px rgba(0,0,0,0.18);
  overflow: hidden;
}

/* gradient accent bar on code blocks */
.reveal pre::before {
  content: '';
  display: block;
  height: var(--border-width);
  background: var(--gradient);
}

.reveal pre code {
  display: block;
  padding: 22px;
  overflow: auto;
  max-height: 420px;
  word-wrap: normal;
  background: transparent;
  color: #d4d4d4;
  font-size: inherit;
  border-radius: 0;
}

/* =============================================
   TABLES
   th color inherits --local-accent
   ============================================= */
.reveal table {
  margin: var(--r-block-margin) auto;
  border-collapse: collapse;
  width: 100%;
  font-size: 0.88em;
}
.reveal table th {
  font-weight: 600;
  font-style: italic;
  color: var(--local-accent);
  border-bottom: 2px solid var(--local-accent);
  padding: 0.5em 0.8em;
  text-align: left;
}
.reveal table td {
  padding: 0.5em 0.8em;
  border-bottom: 1px solid var(--border);
  color: #333;
}
.reveal table tbody tr:last-child td { border-bottom: none; }
.reveal table tbody tr:hover td      { background: rgba(18,179,178,0.04); }

/* =============================================
   IMAGES
   ============================================= */
.reveal img, .reveal video, .reveal iframe {
  max-width: 95%;
  max-height: 75vh;
  border-radius: 8px;
  margin: var(--r-block-margin) 0;
}

/* =============================================
   CARDS
   Each variant sets --local-accent so all h2/h3/h4
   inside automatically use the card's accent color.
   ============================================= */
.reveal .card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 22px 26px;
  box-shadow: 0 2px 12px rgba(0,0,0,0.05);
  --local-accent: var(--sig-4); /* default if no variant */
}

.reveal .card-teal,
.reveal .card-accent { border-top: var(--border-width) solid var(--sig-4); --local-accent: var(--sig-4); }
.reveal .card-purple { border-top: var(--border-width) solid var(--sig-1); --local-accent: var(--sig-1); }
.reveal .card-pink   { border-top: var(--border-width) solid var(--sig-3); --local-accent: var(--sig-3); }
.reveal .card-green  { border-top: var(--border-width) solid var(--sig-5); --local-accent: var(--sig-5); }
.reveal .card-violet { border-top: var(--border-width) solid var(--sig-2); --local-accent: var(--sig-2); }

/* reset top margin on first heading inside any card */
.reveal .card h1, .reveal .card h2,
.reveal .card h3, .reveal .card h4 { margin-top: 0; }

/* =============================================
   GRID LAYOUTS
   ============================================= */
.reveal .grid-2 { display: grid; grid-template-columns: 1fr 1fr;           gap: 20px; margin: 20px 0; }
.reveal .grid-3 { display: grid; grid-template-columns: 1fr 1fr 1fr;       gap: 16px; margin: 20px 0; }
.reveal .grid-4 { display: grid; grid-template-columns: repeat(4,1fr);     gap: 14px; margin: 20px 0; }

/* =============================================
   BADGE
   ============================================= */
.reveal .badge {
  display: inline-block;
  padding: 3px 13px;
  border-radius: 999px;
  font-size: 0.58em;
  font-weight: 600;
  font-style: normal;
  letter-spacing: 0.06em;
  color: #fff;
  background: var(--gradient);
  background-size: 300% 100%;
  vertical-align: middle;
  margin-left: 0.5em;
}

/* =============================================
   TITLE SLIDE
   ============================================= */
.reveal .slides section.title-slide,
.reveal .slides section:first-child { text-align: center; }

.reveal .title-slide .signature-bar {
  height: calc(2*var(--border-width));
  background: var(--gradient);
  border-radius: 4px;
  width: 55%;
  margin: 2rem auto 0;
}

/* =============================================
   DARK BACKGROUND SECTIONS
   ============================================= */
.reveal section.has-dark-background,
.reveal section.has-dark-background h1,
.reveal section.has-dark-background p,
.reveal section.has-dark-background li { color: #fff; }

.reveal section.has-dark-background h2,
.reveal section.has-dark-background h3,
.reveal section.has-dark-background h4 { color: rgba(255,255,255,0.9); }

.reveal section.has-dark-background a { color: rgba(255,255,255,0.8); }
.reveal section.has-dark-background blockquote {
  background: rgba(255,255,255,0.1);
  border-color: rgba(255,255,255,0.3);
}

/* =============================================
   CALLOUTS
   Advanced Slides generates this structure:

   <div class="callout callout-color-{variant}">
     <div class="callout-title">
       <div class="callout-icon">
         <p><svg …/></p>
       </div>
       <div class="callout-title-inner">
         <p>Label</p>
       </div>
     </div>
     <div class="callout-content">
       <p>Body</p>
     </div>
   </div>

   Each variant sets BOTH --final-callout-color (border +
   tab bg) AND --local-accent (so h2/h3/h4 in the
   body adapt automatically — no extra rules needed).
   ============================================= */

.reveal .callout-color-default,
.reveal .callout-color-note      { --final-callout-color: var(--sig-1); --local-accent: var(--sig-1); }
.reveal .callout-color-info      { --final-callout-color: var(--sig-4); --local-accent: var(--sig-4); }
.reveal .callout-color-success   { --final-callout-color: var(--sig-5); --local-accent: var(--sig-5); }
.reveal .callout-color-exp   { --final-callout-color: var(--sig-5); --local-accent: var(--sig-5); }
.reveal .callout-color-warning   { --final-callout-color: var(--sig-3); --local-accent: var(--sig-3); }
.reveal .callout-color-important { --final-callout-color: var(--sig-3); --local-accent: var(--sig-3); }
.reveal .callout-color-secondary { --final-callout-color: var(--sig-2); --local-accent: var(--sig-2); }
.reveal .callout-color-hint      { --final-callout-color: var(--sig-2); --local-accent: var(--sig-2); }

/* ── Outer box ── */
.reveal .callout {
	--final-callout-color: rgb(var(--callout-color));
  position: relative;
  padding: 1.2em 1.2em 1em 1.2em;
  margin: 1em 0;
  margin-top: 2.5em;
  border: var(--border-width) solid var(--final-callout-color), var(--sig-1));
  border-radius: 0.9em;
  background: color-mix(in srgb, var(--final-callout-color, var(--sig-1)) 10%, white);
  box-shadow: 0 0.4em 1.5em rgba(0,0,0,0.06);
  text-align: left;
}

/* ── Tab row ── */
.reveal .callout .callout-title {
  position: absolute;
  top: -2em;
  left: 2em;
  display: flex;
  align-items: center;
  gap: 0.4em;
  padding: 0.35em 0.8em;
  background: var(--final-callout-color, var(--sig-1));
  border-radius: 0.75em 0 0.75em 0;
  margin: 0;
  font-size: 1.52em;
  font-weight: 600;
  font-style: normal;
  letter-spacing: 0.04em;
  line-height: 1;
  color: #fff;
}

/* ── Icon: Advanced Slides wraps SVG in <p> inside .callout-icon ── */
.reveal .callout .callout-icon {
  display: flex;
  align-items: center;
  flex-shrink: 0;
  line-height: 0;
}
.reveal .callout .callout-icon p {
  margin: 0;
  line-height: 0;
  display: flex;
  align-items: center;
  color: #fff;
}
.reveal .callout .callout-icon svg {
  width: 1em;
  height: 1em;
  fill: currentColor;
  color: #fff;
  display: block;
}
.reveal .callout ul {
	margin: 0;
}
/* eTeach <img> fallback */
.reveal .callout .callout-icon img {
  width: 1em;
  height: 1em;
  margin: 0;
  border-radius: 0;
  box-shadow: none;
  filter: brightness(0) invert(1);
}

/* ── Title text: Advanced Slides wraps it in <p> ── */
.reveal .callout .callout-title-inner {
  display: flex;
  align-items: center;
}
.reveal .callout .callout-title-inner p {
  margin: 0;
  color: #fff;
  font-style: normal;
  font-size: inherit;
  line-height: 1;
}

/* ── Content body ── */
.reveal .callout .callout-content {
  font-size: 1em;
  line-height: 1.55;
  color: rgba(0,0,0,0.78);
}
.reveal .callout .callout-content p        { margin: 0.3em 0; color: inherit; }
.reveal .callout .callout-content p:first-child { margin-top: 0; }
.reveal .callout .callout-content p:last-child  { margin-bottom: 0; }

/* headings in callout body automatically pick up --local-accent
   (set on the outer .callout by the color variant class above) */
.reveal .callout .callout-content h2,
.reveal .callout .callout-content h3,
.reveal .callout .callout-content h4 { margin-top: 0.4em; }

/* ── Dark slide ── */
.reveal section.has-dark-background .callout {
  background: rgba(255,255,255,0.08);
  border-color: rgba(255,255,255,0.28);
}
.reveal section.has-dark-background .callout .callout-content {
  color: rgba(255,255,255,0.88);
}

/* =============================================
   eTEACH ICON HELPERS
   https://ludattel.de/eteach/svg/
   eTeach-ICON-{NAME}-001-path-RGB-black.svg
   ============================================= */
.reveal img.eteach-icon {
  width: 2em; height: 2em; margin: 0;
  border-radius: 0; box-shadow: none;
  display: inline-block; vertical-align: middle;
}
.reveal img.eteach-icon.teal   { filter: invert(51%) sepia(90%) saturate(400%) hue-rotate(145deg); }
.reveal img.eteach-icon.purple { filter: invert(28%) sepia(40%) saturate(800%) hue-rotate(220deg); }
.reveal img.eteach-icon.pink   { filter: invert(65%) sepia(40%) saturate(700%) hue-rotate(300deg); }
.reveal img.eteach-icon.green  { filter: invert(65%) sepia(30%) saturate(500%) hue-rotate(90deg);  }
.reveal img.eteach-icon.white  { filter: brightness(0) invert(1); }
.reveal img.eteach-icon.large  { width: 4em; height: 4em; }

/* =============================================
   PROGRESS BAR + CONTROLS
   ============================================= */
.reveal .progress { height: 5px; background: rgba(0,0,0,0.1); }
.reveal .progress span {
  background: var(--gradient);
  background-size: 200% 100%;
  transition: width 800ms cubic-bezier(0.26,0.86,0.44,0.985);
}
.reveal .controls { color: var(--sig-4); }
.reveal .controls button:hover { color: var(--sig-1); }
.reveal .slide-number {
  background: transparent;
  color: var(--text-muted);
  font-family: var(--r-code-font);
  font-size: 0.55em;
}

.reveal figure {
  display: block !important;
  text-align: center !important;
  align-content: center;
}

.reveal figure img {
  width: auto;
  display: block;
  margin: 0 auto;
}

.reveal figure figcaption {
  margin: 20px 0 0 0;
  padding: 9px 15px;
  padding-left: 20px;
  text-align: left;
  font-size: var(--caption-size);
  background: color-mix(in srgb, var(--sig-1) 10%, transparent);
  border-left: var(--border-width) solid var(--sig-1);
  border-radius: 10px;
  opacity: 1;

}


/*********************************************
 * SOURCE INFO BOX (ludigraphs)
 *********************************************/
.reveal .sourceInfoBox {
  position: absolute;
  bottom: 14px;
  left: 20px;
  max-width: calc(100% - 40px);
  margin: 0;
  padding: 0 0 0 1.5em;
  font-family: var(--r-main-font);
  font-size: 0.78em;
  line-height: 1.35;
  font-weight: 400;
  letter-spacing: 0.01em;
  color: var(--r-main-color);
  opacity: 0.45;
  pointer-events: none;
  z-index: 20;
}

.reveal .sourceInfoBox::before {
  content: "🛈";
  position: absolute;
  left: 0;
  top: 50%;
  width: 0.85em;
  height: 0.85em;
  transform: translateY(-50%);
  opacity: 0.7;

}