/* Nebula — the Foundation's sharing surface: the `/workshops`,
   `/presentations`, and `/show-and-tell` indexes and every material page
   beneath them.

   Self-contained on its own `--neb-*` ramp, hoisted by the Dioxus pages that
   need it, the same way `product-hero.css` serves the service heroes. The
   `PageLayout` linked `brand.css` on every render, so these rules used to
   arrive for free; a Dioxus page loads only what it names.

   The hero is deep space with a star being born: two drifting starfields, a
   cloud of nebula gas, a pulsing core, and an expanding shockwave — matching
   the page's name, since a nebula is where new stars (new ideas) are made. Two
   themes follow `prefers-color-scheme` (dark deep space / light daylight
   nebula), both on the one cyan ramp. Every bit of motion is decorative, hidden
   from the a11y tree, and frozen wholesale under `prefers-reduced-motion` — the
   same access-to-justice restraint the service heroes keep, no strobe for
   someone in crisis. */

.nebula-hero {
  /* The brand cyan ramp — the only hue, mirroring `product-hero.css`. */
  --neb-accent: #22d3ee;
  --neb-bright: #67e8f9;
  --neb-deep: #0891b2;
  --neb-soft: #a5f3fc;

  position: relative;
  isolation: isolate;
  overflow: hidden;
  min-height: clamp(21rem, 48vw, 34rem);
  margin-bottom: 3rem;
  border-radius: 0.5rem;
  color: #fff;
  /* Deep space: two faint cyan nebula washes over a near-black field. */
  background:
    radial-gradient(ellipse 64% 56% at 72% 30%, rgba(8, 145, 178, 0.34), transparent 62%),
    radial-gradient(ellipse 58% 66% at 18% 82%, rgba(34, 211, 238, 0.16), transparent 64%),
    linear-gradient(180deg, #03040a 0%, #061018 58%, #04070f 100%);
}

.nebula-hero-media {
  position: absolute;
  inset: 0;
}

/* A soft vignette so the bottom-left copy stays legible over the moving
   scene — light enough that the stars still read through it. */
.nebula-hero-media::after {
  position: absolute;
  inset: 0;
  content: "";
  background:
    linear-gradient(90deg, rgba(3, 5, 12, 0.72), rgba(3, 5, 12, 0.32) 52%, rgba(3, 5, 12, 0)),
    linear-gradient(0deg, rgba(3, 5, 12, 0.66), rgba(3, 5, 12, 0) 60%);
}

/* Two tiled starfields drifting at different speeds for parallax. Each plane is
   a handful of tiny radial-gradient dots repeated across the scene; the whole
   plane twinkles (opacity) and drifts (background position). */
.nebula-hero__stars,
.nebula-hero__stars--far {
  position: absolute;
  inset: 0;
  background-repeat: repeat;
  background-image:
    radial-gradient(1.5px 1.5px at 40px 60px, #fff, transparent),
    radial-gradient(1px 1px at 130px 100px, var(--neb-soft), transparent),
    radial-gradient(1.5px 1.5px at 200px 168px, var(--neb-bright), transparent),
    radial-gradient(1px 1px at 92px 224px, #fff, transparent),
    radial-gradient(1px 1px at 252px 44px, var(--neb-soft), transparent),
    radial-gradient(1.5px 1.5px at 280px 256px, var(--neb-accent), transparent);
  background-size: 300px 300px;
  animation:
    nebula-twinkle 4.5s ease-in-out infinite,
    nebula-drift 90s linear infinite;
}

.nebula-hero__stars--far {
  background-size: 210px 210px;
  opacity: 0.6;
  animation:
    nebula-twinkle 6.5s ease-in-out infinite 1.2s,
    nebula-drift 150s linear infinite reverse;
}

/* The nebula gas — soft blurred cyan clouds that breathe and drift, the cradle
   the new star forms inside. */
.nebula-hero__cloud {
  position: absolute;
  inset: -12%;
  background:
    radial-gradient(38% 50% at 70% 32%, color-mix(in srgb, var(--neb-accent) 32%, transparent), transparent 70%),
    radial-gradient(30% 42% at 30% 60%, color-mix(in srgb, var(--neb-bright) 22%, transparent), transparent 72%),
    radial-gradient(26% 36% at 82% 70%, color-mix(in srgb, var(--neb-deep) 28%, transparent), transparent 72%);
  filter: blur(26px);
  animation: nebula-cloud 26s ease-in-out infinite alternate;
}

/* The star being born, anchored to the densest knot of gas (72% / 32%): a
   bright pulsing core... */
.nebula-hero__core {
  position: absolute;
  left: 72%;
  top: 32%;
  width: 12px;
  height: 12px;
  margin: -6px 0 0 -6px;
  border-radius: 50%;
  background: radial-gradient(circle, #fff 0%, var(--neb-bright) 42%, transparent 72%);
  box-shadow:
    0 0 14px 4px var(--neb-bright),
    0 0 40px 12px color-mix(in srgb, var(--neb-accent) 70%, transparent);
  animation: nebula-core 5s ease-in-out infinite;
}

/* ...wrapped in a shockwave ring that expands and fades — the explosion. */
.nebula-hero__burst {
  position: absolute;
  left: 72%;
  top: 32%;
  width: 16px;
  height: 16px;
  margin: -8px 0 0 -8px;
  border-radius: 50%;
  border: 2px solid color-mix(in srgb, var(--neb-bright) 82%, transparent);
  transform: scale(0);
  animation: nebula-burst 7s ease-out infinite;
}

/* The copy block sits above the scene and is padded here rather than by the
   Bootstrap `py-5 px-4 px-lg-5` utilities the header used, so the layout
   survives Bootstrap's removal (#877). `mb-5` on the banner becomes the
   `.nebula-hero` margin below. */
.nebula-hero-copy {
  position: relative;
  display: flex;
  min-height: inherit;
  max-width: 48rem;
  flex-direction: column;
  justify-content: flex-end;
  padding: 3rem 1.5rem;
}

@media (min-width: 992px) {
  .nebula-hero-copy {
    padding: 3rem;
  }
}

/* The small uppercase attribution above the wordmark. The header spelled
   this with Bootstrap utilities (`text-uppercase small fw-semibold mb-2`); it
   is a named class here so the rule survives Bootstrap's removal (#877). */
.nebula-hero__eyebrow {
  margin-bottom: 0.5rem;
  font-size: 0.875rem;
  font-weight: 600;
  text-transform: uppercase;
}

.nebula-hero h1 {
  font-size: 5.5rem;
  line-height: 0.95;
  /* A gentle cyan halo ties the wordmark to the service heroes' glow. */
  text-shadow:
    0 0 8px color-mix(in srgb, var(--neb-bright) 60%, transparent),
    0 0 28px color-mix(in srgb, var(--neb-deep) 55%, transparent);
}

.nebula-hero .lede {
  max-width: 44rem;
  color: rgba(255, 255, 255, 0.88);
}

@keyframes nebula-twinkle {
  0%,
  100% {
    opacity: 0.45;
  }
  50% {
    opacity: 1;
  }
}

@keyframes nebula-drift {
  from {
    background-position: 0 0;
  }
  to {
    background-position: 300px -300px;
  }
}

@keyframes nebula-cloud {
  from {
    transform: translate3d(-3%, 2%, 0) scale(1);
  }
  to {
    transform: translate3d(3%, -2%, 0) scale(1.08);
  }
}

@keyframes nebula-core {
  0%,
  100% {
    transform: scale(0.8);
    opacity: 0.85;
  }
  50% {
    transform: scale(1.28);
    opacity: 1;
  }
}

@keyframes nebula-burst {
  0% {
    transform: scale(0);
    opacity: 0.9;
  }
  72% {
    opacity: 0.22;
  }
  100% {
    transform: scale(26);
    opacity: 0;
  }
}

/* ------------------------------------------------------------------ */
/* LIGHT variant — "daylight nebula": the same cyan ramp re-tinted for  */
/* white paper. Deeper cyans hold contrast on white, and the copy flips */
/* to ink so it reads on the pale sky.                                  */
/*                                                                      */
/* Keyed on `prefers-color-scheme` so the hero follows the shared token */
/* layer without requiring a JavaScript theme toggle.                    */
/* ------------------------------------------------------------------ */
@media (prefers-color-scheme: light) {
  .nebula-hero {
    color: #04161d;
    background:
      radial-gradient(ellipse 64% 56% at 72% 30%, rgba(34, 211, 238, 0.22), transparent 62%),
      radial-gradient(ellipse 58% 66% at 18% 82%, rgba(8, 145, 178, 0.12), transparent 64%),
      linear-gradient(180deg, #ecfeff 0%, #f3fdff 56%, #ffffff 100%);
  }

  /* Cyan-ink stars so the dots read as a daytime sparkle on white. */
  .nebula-hero__stars,
  .nebula-hero__stars--far {
    background-image:
      radial-gradient(1.5px 1.5px at 40px 60px, var(--neb-deep), transparent),
      radial-gradient(1px 1px at 130px 100px, var(--neb-accent), transparent),
      radial-gradient(1.5px 1.5px at 200px 168px, #0e7490, transparent),
      radial-gradient(1px 1px at 92px 224px, var(--neb-deep), transparent),
      radial-gradient(1px 1px at 252px 44px, var(--neb-accent), transparent),
      radial-gradient(1.5px 1.5px at 280px 256px, #0e7490, transparent);
  }

  /* Pale vignette so ink copy reads on the bright scene. */
  .nebula-hero-media::after {
    background:
      linear-gradient(90deg, rgba(236, 254, 255, 0.72), rgba(236, 254, 255, 0.2) 52%, rgba(236, 254, 255, 0)),
      linear-gradient(0deg, rgba(255, 255, 255, 0.62), rgba(255, 255, 255, 0) 60%);
  }

  /* Ink wordmark with a soft cyan halo — no neon on paper. */
  .nebula-hero h1 {
    color: #04161d;
    text-shadow: 0 0 18px rgba(34, 211, 238, 0.3);
  }

  .nebula-hero .lede {
    color: rgba(4, 22, 29, 0.78);
  }
}

/* Access-to-justice restraint: freeze the scene to a still, dignified space
   banner for anyone who asks for reduced motion. */
@media (prefers-reduced-motion: reduce) {
  .nebula-hero__stars,
  .nebula-hero__stars--far,
  .nebula-hero__cloud,
  .nebula-hero__core {
    animation: none;
  }

  .nebula-hero__burst {
    display: none;
  }
}

/* ------------------------------------------------------------------ */
/* The material lists and the show-and-tell cards.                      */
/* ------------------------------------------------------------------ */

/* The landing's material lists. The markup got its bullet removal and
   bottom margin from Bootstrap's `list-unstyled mb-5`; both are named rules
   here so the lists survive Bootstrap's removal (#877). */
.nebula-materials {
  margin-bottom: 3rem;
  padding-left: 0;
  list-style: none;
}

/* One Nebula material (a workshop, a presentation, or a gathering) in the
   landing's lists. */
.nebula-material {
  margin-bottom: 1.5rem;
}

.nebula-material h3 {
  font-size: 1.25rem;
  line-height: 1.2;
}

/* The small uppercase line above a material's title: who it is for, or when a
   gathering happens. */
.nebula-eyebrow {
  margin-bottom: 0.25rem;
  color: var(--nav-color-text-muted);
  font-size: 0.875rem;
  font-weight: 600;
  text-transform: uppercase;
}

.nebula-empty,
.nebula-more {
  color: var(--nav-color-text-muted);
}

.nebula-more {
  font-style: italic;
}

/* The show-and-tell index is a vertical list of horizontal cards: a small image
   thumbnail on the left, the title/description/actions on the right. */
.show-tell-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1rem;
}

.show-tell-card {
  display: flex;
  align-items: stretch;
  overflow: hidden;
  border: 1px solid var(--nav-color-border);
  border-radius: var(--nav-radius);
  background: var(--nav-color-surface);
}

.show-tell-card-media {
  display: block;
  flex: 0 0 clamp(8.5rem, 18vw, 13rem);
  overflow: hidden;
  background: var(--nav-color-surface-subtle);
}

.show-tell-card-media img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

/* An event with no image: the body spans the full card width. */
.show-tell-card-body:only-child {
  flex-basis: 100%;
}

.show-tell-card-body {
  display: flex;
  flex: 1 1 auto;
  min-width: 0;
  flex-direction: column;
  justify-content: center;
  gap: 0.25rem;
  padding: 1rem;
}

.show-tell-card-body h3 {
  font-size: 1.25rem;
  line-height: 1.2;
}

.show-tell-card-body p {
  margin-bottom: 0.75rem;
}

/* Each half of the archive — "Upcoming" and "Past". The markup spaced
   these with Bootstrap's `mt-5 mb-3` utilities. */
.show-tell-section {
  margin-bottom: 3rem;
}

.show-tell-section h2 {
  margin-bottom: 0.25rem;
}

/* The one-line note under each half's heading ("Today forward, nearest
   first."). Plain muted body text, not an eyebrow — the markup spelled it
   `text-body-secondary mb-0`. */
.show-tell-section__note {
  margin-bottom: 1rem;
  color: var(--nav-color-text-muted);
}

/* One gathering's detail page. The version borrowed the blog's
   `.blog-post` / `.blog-date` classes plus an inline `max-width: 65ch` cap;
   the measure is class-driven here — the same move the service page made when
   it replaced its inline cap with `.service-open-letter`. */
.show-tell-detail {
  max-width: 65ch;
  margin-inline: auto;
}

.show-tell-detail__date {
  color: var(--nav-color-text-muted);
  font-size: 0.875rem;
}

/* The event picture on a gathering's detail page. The page got this from
   Bootstrap's `img-fluid rounded`; it is a named rule here so the picture keeps
   its size and corners after Bootstrap leaves (#877). */
.show-tell-detail__image {
  max-width: 100%;
  height: auto;
  border-radius: var(--nav-radius);
}

@media (max-width: 575.98px) {
  .show-tell-card-media {
    display: none;
  }

  .show-tell-card-body {
    padding: 0.875rem;
  }

  .nebula-hero {
    min-height: 26rem;
  }

  .nebula-hero h1 {
    font-size: 3.25rem;
  }

  .nebula-hero-media::after {
    background: linear-gradient(0deg, rgba(3, 5, 12, 0.9), rgba(3, 5, 12, 0.36));
  }
}

@media (min-width: 992px) {
  .nebula-hero h1 {
    font-size: 6.5rem;
  }
}

/* Bootstrap shipped `box-sizing: border-box` as a global reset, so every rule
   written against the pages assumed it. A Dioxus page loads only what it
   names and `theme.css` carries no reset, so these surfaces state it for
   themselves — without it a padded element sized in percent or `dvh` overflows
   its own box (the slide canvas clips its text; the projector shell overruns
   the viewport by twice its padding). Scoped to the page roots below rather
   than declared globally: the hero is already tuned against the browser
   default, and a document-wide reset is `theme.css`'s to make when Bootstrap
   leaves for good (#877). */
:is(
  .material-page,
  .workshop-step,
  .workshop-lighttable,
  .workshop-cert-sent,
  .nebula-display
),
:is(
    .material-page,
    .workshop-step,
    .workshop-lighttable,
    .workshop-cert-sent,
    .nebula-display
  )
  * {
  box-sizing: border-box;
}

/* ------------------------------------------------------------------ */
/* The material surface: a workshop or presentation hub, and the       */
/* light-table grid of its slides.                                     */
/*                                                                     */
/* These pages had almost no CSS of their own — their whole appearance */
/* came from Bootstrap *components* (`card`, `badge`, `list-group`,    */
/* `form-control`) that the layout linked on every render, not    */
/* from `brand.css`. So this is a rebuild on the theme's `--nav-*`     */
/* tokens rather than a port of existing rules.                        */
/* ------------------------------------------------------------------ */

.material-page,
.workshop-lighttable,
.workshop-cert-sent {
  max-width: 72rem;
  margin-inline: auto;
}

.workshop-cert-sent {
  padding-block: 3rem;
  text-align: center;
}

.material-header {
  margin-bottom: 1.5rem;
}

/* The material's own lede reads as body copy, not the hero treatment the
   `.nebula-hero .lede` rule gives the landing wordmark. */
.material-page .lede,
.workshop-cert-sent .lede {
  color: var(--nav-color-text);
  font-size: 1.125rem;
}

/* Material Markdown is reading prose, unlike the compact site chrome. Keep
   links visibly distinct even when neither pointer hover nor colour is
   available. */
.nav-theme .material-page :is(.material-intro, .material-body, .workshop-chapter__preamble) a {
  text-decoration: underline;
  text-decoration-thickness: 0.08em;
  text-underline-offset: 0.14em;
}

.material-intro {
  margin-bottom: 1.5rem;
}

/* Start / slides / markdown, wrapping on narrow viewports. Replaces the
   `d-flex flex-wrap gap-2 my-4` utilities the markup used. */
.material-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin-block: 1.5rem 2rem;
}

.material-outline,
.lighttable-chapters {
  display: grid;
  gap: 1.5rem;
}

.lighttable-chapters {
  gap: 3rem;
}

/* One chapter, on both the outline and the light table. The markup drew
   this as a Bootstrap `card` + `card-header`; it is a plain bordered panel on
   the theme tokens here. */
.workshop-chapter {
  border: 1px solid var(--nav-color-border);
  border-radius: var(--nav-radius);
  background: var(--nav-color-surface);
}

.workshop-chapter__header {
  display: flex;
  align-items: flex-start;
  gap: 1rem;
  padding: 1rem;
  border-bottom: 1px solid var(--nav-color-border);
}

.workshop-chapter__title {
  margin: 0;
  font-size: 1.25rem;
}

.workshop-chapter__preamble {
  margin-top: 0.5rem;
  font-size: 0.875rem;
}

/* The successor to Bootstrap's `badge text-bg-primary rounded-pill` — the
   chapter number, and the light table's viewed count. */
.nebula-badge {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 1.75rem;
  padding: 0.25rem 0.6rem;
  border-radius: 999px;
  background: var(--nav-color-primary);
  color: var(--nav-color-on-primary);
  font-size: 0.875rem;
  font-weight: 600;
  white-space: nowrap;
}

/* The chapter's ordered steps — the successor to `list-group-flush`. */
.workshop-steps {
  margin: 0;
  padding: 0;
  list-style: none;
}

.workshop-steps__item {
  display: flex;
  gap: 1rem;
  padding: 0.625rem 1rem;
  border-top: 1px solid var(--nav-color-border);
}

.workshop-steps__item:first-child {
  border-top: 0;
}

.workshop-steps__number {
  color: var(--nav-color-text-muted);
  font-variant-numeric: tabular-nums;
}

.lighttable-header {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 0.5rem;
  margin-bottom: 0.5rem;
}

/* The thumbnail grid. Replaces `row row-cols-1 row-cols-md-2 row-cols-xl-3`. */
.lighttable-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(15rem, 1fr));
  gap: 1rem;
  padding: 1rem;
}

/* Every thumbnail is the same size regardless of how much its slide holds, so
   the grid reads as a contact sheet. The caption is pinned to the bottom by
   `margin-top: auto`; without that a short slide floats its caption up and the
   row stops lining up. */
.slide-thumb {
  position: relative;
  display: flex;
  height: 100%;
  min-width: 0;
  flex-direction: column;
  overflow: hidden;
  border: 1px solid var(--nav-color-border);
  border-radius: var(--nav-radius);
  background: var(--nav-color-surface-raised);
  color: inherit;
}

/* The shrunk slide face. Decorative and `aria-hidden`, so it is clipped rather
   than made readable — the caption below carries the accessible label. */
/* A fixed height, not a max: the whole point is that every cell matches. The
   miniature is clipped rather than scaled, and it is `aria-hidden`, so losing
   the tail costs nothing — the caption carries the readable label. */
.slide-thumb__preview {
  height: 9rem;
  overflow: hidden;
  padding: 0.5rem;
  font-size: 0.6rem;
  line-height: 1.3;
}

/* Keep a slide's own headings from blowing out the miniature. */
.slide-thumb__preview :is(h1, h2, h3, h4) {
  font-size: 0.75rem;
  margin: 0 0 0.25rem;
}

.slide-thumb__preview :is(p, ul, ol, pre) {
  margin: 0 0 0.25rem;
}

/* Syntect gives code tokens inline colours that belong to their full-size slide
   face. A thumbnail is decorative and too small to preserve that palette, so
   keep its tiny source legible against the shared surface instead. */
.slide-thumb__preview pre {
  background: var(--nav-color-surface) !important;
  color: var(--nav-color-text) !important;
}

.slide-thumb__preview pre span {
  color: inherit !important;
}

.slide-thumb__caption {
  margin-top: auto;
  overflow: hidden;
  padding: 0.35rem 0.5rem;
  border-top: 1px solid var(--nav-color-border);
  font-size: 0.8125rem;
  text-overflow: ellipsis;
  white-space: nowrap;
}

/* Painted by `workshop-progress.js` once the learner has opened the slide; it
   drops the `hidden` attribute rather than toggling a class. */
.slide-seen-badge {
  position: absolute;
  top: 0.25rem;
  right: 0.25rem;
  z-index: 1;
  color: var(--nav-color-success);
  font-weight: 700;
}

/* Revealed by the same script once every slide has been seen. */
.workshop-certificate {
  margin-top: 2rem;
  padding: 1.25rem;
  border: 1px solid var(--nav-color-success);
  border-radius: var(--nav-radius);
  background: var(--nav-color-surface);
}

.workshop-certificate__form {
  display: flex;
  flex-wrap: wrap;
  align-items: flex-end;
  gap: 0.75rem;
}

.workshop-certificate__field {
  display: flex;
  min-width: 14rem;
  flex: 1 1 14rem;
  flex-direction: column;
  gap: 0.25rem;
}

.workshop-certificate__field label {
  font-size: 0.875rem;
}

.workshop-certificate__field input {
  padding: 0.45rem 0.6rem;
  border: 1px solid var(--nav-color-border);
  border-radius: var(--nav-radius-sm);
  background: var(--nav-color-bg);
  color: var(--nav-color-text);
  font-family: inherit;
  font-size: 1rem;
}

.workshop-certificate__field input:focus-visible {
  outline: 2px solid var(--nav-color-primary);
  outline-offset: 1px;
}

/* ------------------------------------------------------------------ */
/* The presenter surface: the classroom step page and the full-screen  */
/* display face a presenter projects on a second screen.               */
/*                                                                     */
/* The slide canvas and the display shell moved here from `brand.css`  */
/* with the pages that emit them — they were the last rules in that    */
/* file these routes read, and a Dioxus page loads only what it names. */
/* The rail, the section menu, and the presenter notes are new: they   */
/* had no rules of their own at all, because the markup drew them */
/* entirely out of Bootstrap utilities and a Bootstrap dropdown.       */
/* ------------------------------------------------------------------ */

.workshop-step {
  max-width: 72rem;
  margin-inline: auto;
}

/* Back to the hub, where you are, and the jump-to-section menu — pinned above
   the slide so orientation is never stranded behind a Next button. */
.workshop-rail {
  margin-bottom: 1.5rem;
}

.workshop-rail__top {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 0.5rem;
  margin-bottom: 0.5rem;
}

.workshop-rail__back {
  font-size: 0.875rem;
  text-decoration: none;
}

.workshop-rail__back:hover {
  text-decoration: underline;
}

.workshop-rail__meta {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.workshop-rail__chapter {
  margin: 0;
  font-size: 0.875rem;
  font-weight: 600;
}

.workshop-rail__position {
  margin: 0;
  color: var(--nav-color-text-muted);
  font-size: 0.875rem;
}

/* Workshop progress indicator. */
.workshop-progress {
  overflow: hidden;
  height: 0.5rem;
  border-radius: 999px;
  background: var(--nav-color-surface-raised);
}

.workshop-progress__bar {
  height: 100%;
  background: var(--nav-color-primary);
}

/* The jump-to-section menu is a native `<details>` disclosure. It needs no
   script, opens before hydration, and is keyboard-accessible by default. */
.workshop-sections {
  position: relative;
}

.workshop-sections__toggle {
  padding: 0.3rem 0.75rem;
  border: 1px solid var(--nav-color-border);
  border-radius: var(--nav-radius-sm);
  background: var(--nav-color-surface);
  color: var(--nav-color-text);
  cursor: pointer;
  font-size: 0.875rem;
  list-style: none;
  white-space: nowrap;
}

/* Safari draws its own disclosure triangle through a pseudo-element that
   `list-style: none` does not reach. */
.workshop-sections__toggle::-webkit-details-marker {
  display: none;
}

.workshop-sections__toggle::after {
  content: " ▾";
}

.workshop-sections__toggle:focus-visible {
  outline: 2px solid var(--nav-color-primary);
  outline-offset: 1px;
}

.workshop-sections__menu {
  position: absolute;
  z-index: 3;
  top: calc(100% + 0.25rem);
  right: 0;
  min-width: 18rem;
  max-height: min(70vh, 38rem);
  overflow-y: auto;
  padding: 0.5rem 0;
  border: 1px solid var(--nav-color-border);
  border-radius: var(--nav-radius);
  background: var(--nav-color-surface);
  box-shadow: var(--nav-shadow);
}

.workshop-sections__header {
  margin: 0;
  padding: 0.4rem 1rem 0.2rem;
  color: var(--nav-color-text-muted);
  font-size: 0.75rem;
  font-weight: 600;
  text-transform: uppercase;
}

.workshop-sections__list {
  margin: 0;
  padding: 0;
  list-style: none;
}

/* Written against `.nav-theme a` rather than the bare class: that rule sets
   every anchor to the cyan link colour and out-specifies a lone class, so the
   entries would read as a wall of links and — worse — the highlighted entry
   would land cyan-on-cyan over its filled background. This is the same
   specificity bump `theme.css` makes for `a.nav-btn--*`, and the same defect:
   a menu that looks styled and fails contrast outright. */
.nav-theme a.workshop-sections__item {
  display: block;
  padding: 0.35rem 1rem;
  color: var(--nav-color-text);
  font-size: 0.9375rem;
  text-decoration: none;
}

.nav-theme a.workshop-sections__item:hover {
  background: var(--nav-color-surface-raised);
  color: var(--nav-color-text);
}

.nav-theme a.workshop-sections__item--current,
.nav-theme a.workshop-sections__item--current:hover {
  background: var(--nav-color-primary);
  color: var(--nav-color-on-primary);
  font-weight: 600;
}

/* Nebula slide faces use Keynote's wide canvas shape: 16:9, equivalent to
   1920x1080 when an export pipeline needs pixels. The successor to the
   Bootstrap `card shadow-sm position-relative` the markup used. */
.workshop-slide {
  position: relative;
  overflow: hidden;
  aspect-ratio: 16 / 9;
  border: 1px solid var(--nav-color-border);
  border-radius: var(--nav-radius);
  background: var(--nav-color-surface);
  box-shadow: var(--nav-shadow);
}

.workshop-slide > .material-body {
  height: 100%;
  min-height: 0;
  overflow: auto;
  padding: clamp(1rem, 3vw, 2rem);
}

.workshop-slide > .material-body > :last-child {
  margin-bottom: 0;
}

.workshop-slide :is(h2, h3) {
  overflow-wrap: anywhere;
}

/* The speaker notes beneath the slide, like a Keynote presenter display. */
.presenter-notes {
  margin-top: 1rem;
}

.presenter-notes__label {
  margin: 0 0 0.5rem;
  color: var(--nav-color-text-muted);
  font-size: 0.875rem;
  font-weight: 600;
  letter-spacing: 0.04em;
  text-transform: uppercase;
}

.workshop-step__links {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 1.5rem;
  margin-top: 1rem;
  font-size: 0.875rem;
}

.workshop-step__nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.5rem;
  margin-top: 1.5rem;
}

/* Nebula full-screen display mode (`…/display/{n}`): one slide, centered and
   scaled to the largest 16:9 box that fits the viewport, on a bare page with no
   site chrome — a presenter's external monitor shows only the slide. `dvh`
   tracks the mobile dynamic viewport so a phone address bar doesn't clip it. */
.nebula-display {
  --nebula-display-pad: clamp(0.5rem, 3vw, 2.5rem);
  position: fixed;
  inset: 0;
  display: flex;
  overflow: hidden;
  align-items: center;
  justify-content: center;
  padding: var(--nebula-display-pad);
  background: var(--nav-color-bg);
}

.nebula-display-slide {
  /* Largest 16:9 box that fits: the viewport width, or the width a
     height-limited 16:9 card would take — whichever is smaller.
     `.workshop-slide` supplies the aspect-ratio itself. `min-width: 0` stops a
     wide code block inside the slide from forcing the flex item past the
     viewport (flex items default to their content min-width). */
  width: min(100%, (100dvh - 2 * var(--nebula-display-pad)) * 16 / 9);
  min-width: 0;
  max-height: calc(100dvh - 2 * var(--nebula-display-pad));
  margin: 0;
  cursor: pointer;
}

/* The controls are near-invisible until the presenter moves the pointer or tabs
   to them, so a full-screen slide is uncluttered. */
.nebula-display-controls {
  position: fixed;
  z-index: 2;
  bottom: clamp(0.5rem, 2vh, 1.5rem);
  left: 50%;
  display: flex;
  align-items: center;
  gap: 0.75rem;
  opacity: 0;
  transform: translateX(-50%);
  transition: opacity 0.2s ease-in-out;
}

.nebula-display:hover .nebula-display-controls,
.nebula-display-controls:focus-within {
  opacity: 1;
}

/* Touch screens have no hover, so keep the controls visible there. */
@media (hover: none) {
  .nebula-display-controls {
    opacity: 1;
  }
}

@media (prefers-reduced-motion: reduce) {
  .nebula-display-controls {
    transition: none;
  }
}

/* The chevrons are chrome, not prose links, so they carry the body colour
   rather than the cyan `.nav-theme a` gives every anchor — stated at matching
   specificity because that rule would otherwise win. */
.nebula-display-nav,
.nav-theme a.nebula-display-nav,
.nav-theme a.nebula-display-nav:hover {
  display: inline-flex;
  width: 2.75rem;
  height: 2.75rem;
  align-items: center;
  justify-content: center;
  border: 1px solid var(--nav-color-border);
  border-radius: 50%;
  background: var(--nav-color-surface-raised);
  color: var(--nav-color-text);
  font-size: 1.5rem;
  line-height: 1;
  text-decoration: none;
}

.nebula-display-nav--disabled {
  opacity: 0.35;
  pointer-events: none;
}