/* =========================================================
   AC-v3 Image lightbox + info-icon affordance (16.05.26, info-icon 17.05.26)

   Opt-in: any element with [data-lightbox] gets an info-icon
   button injected by lightbox.js. Click opens a full-viewport
   lightbox showing the largest srcset variant, with an optional
   caption (data-lightbox-caption, or img alt as fallback).

   Video case: [data-lightbox-video="<youtube-id>"] swaps the
   image for a 16:9 YouTube iframe in the same lightbox shell.

   Accessibility: aria-modal, focus moves to close on open,
   focus returns to the trigger on close, Esc dismisses, Tab is
   trapped inside the modal.
   ========================================================= */

/* ---------- Info-icon button (18.05.26 restyle, third pass) ----------
   Bottom-right corner of an opt-in figure. The pill is now sized to
   the icon (icon 26px, button 28px = 2px padding around the glyph)
   with a stronger white opacity layer so it reads as a tiny crisp
   light puck rather than a vague slab. SVG inherits currentColor;
   hover flips colour to --accent. */
.lightbox-trigger {
  position: absolute;
  right: 12px;
  bottom: 12px;
  z-index: 5;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 28px;
  height: 28px;
  padding: 0;
  border: 0;
  border-radius: 999px;
  /* 19.05.26: opaque white-glass backdrop retired per user. Icon
     now sits on the image / page directly. Drop-shadow on the SVG
     (see .lightbox-trigger svg) gives it enough contrast to read
     against any backdrop without a circular plate behind it. */
  background: transparent;
  color: #FFFFFF;
  cursor: pointer;
  transition: color 160ms ease, transform 160ms ease;
  -webkit-tap-highlight-color: transparent;
  /* 16.05.26: forced auto so the trigger receives clicks regardless of
     parent pointer-events. Needed because .btm-stage__figure has
     pointer-events: none (legacy section-btm.css rule whose .btm-selector
     override no longer matches the v4 DOM), which silently blocked the
     info-icon on every BtM era. */
  pointer-events: auto;
}
.lightbox-trigger:hover,
.lightbox-trigger:focus-visible {
  color: var(--accent);
  transform: scale(1.08);
}
.lightbox-trigger:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}
.lightbox-trigger svg {
  width: 26px;
  height: 26px;
  display: block;
  /* 19.05.26: drop-shadow on the SVG itself replaces the prior
     white-glass backdrop. Two-layer shadow gives enough contrast
     to read on both light and dark image areas without a plate. */
  filter:
    drop-shadow(0 1px 2px rgba(0, 0, 0, 0.7))
    drop-shadow(0 0 4px rgba(0, 0, 0, 0.45));
}

/* ---------- Overlay ----------
   Full-viewport modal. Hidden by default. 19.05.26: align-items
   flipped from center to flex-start so the panel anchors to the
   TOP of the viewport rather than centring vertically. With centred
   alignment, a longer caption (e.g. BtM Era 2 WFOB vs eras 1 + 3,
   or the AOoS caption with the bone-flute note) made the panel
   taller, which pushed the image upward to keep the panel centred -
   so the image visually shifted between adjacent lightbox views as
   the user navigated prev/next. Top-anchoring pins the image at a
   consistent screen position; captions extend downward as needed. */
.lightbox {
  position: fixed;
  inset: 0;
  z-index: 9999;
  display: none;
  align-items: flex-start;
  justify-content: center;
  padding: var(--s-5);
  background: rgba(0, 0, 0, 0.92);
  overflow-y: auto;
}
.lightbox.is-open {
  display: flex;
}
.lightbox__panel {
  position: relative;
  max-width: min(1200px, 92vw);
  max-height: 92vh;
  display: flex;
  flex-direction: column;
  gap: var(--s-4);
  z-index: 1;
}

/* ---------- Media slot (image or video) ---------- */
.lightbox__media {
  display: flex;
  align-items: center;
  justify-content: center;
  max-height: 80vh;
}
.lightbox__media img {
  max-width: 100%;
  max-height: 80vh;
  display: block;
  border-radius: 4px;
}
.lightbox__media iframe {
  width: min(1200px, 92vw);
  aspect-ratio: 16 / 9;
  height: auto;
  display: block;
  border: 0;
  border-radius: 4px;
}

/* ---------- Caption ----------
   Pulls from data-lightbox-caption, fallback to img alt. 19.05.26:
   lightbox.js now writes caption via innerHTML so inline markup
   (links, <small> aside notes) renders. */
.lightbox__caption {
  margin: 0;
  color: #FFFFFF;
  font-family: var(--font-serif);
  font-size: var(--body-small);
  line-height: 1.55;
  text-align: center;
  /* 19.05.26: widened from 70ch (~600px) to min(900px, 90vw) per
     user direction - matches the .et-card prose container width so
     the caption reads at the same visual scale as the site's other
     long-form text rather than as a narrow column. */
  max-width: min(900px, 90vw);
  margin-inline: auto;
}
.lightbox__caption[hidden] {
  display: none;
}
.lightbox__caption a {
  color: inherit;
  text-decoration: underline;
  text-decoration-color: rgba(255, 255, 255, 0.55);
  text-underline-offset: 2px;
  transition: text-decoration-color 160ms ease;
}
.lightbox__caption a:hover,
.lightbox__caption a:focus-visible {
  text-decoration-color: #FFFFFF;
}
/* 19.05.26: footnote-style aside inside a lightbox caption. Used for
   the AOoS bone-flute note (no Irish prehistoric bone instruments
   survive; we proceed on the global record). Sits on its own line
   beneath the main descriptive sentence, smaller and muted so it
   reads as commentary not description. */
.lightbox__caption-note {
  display: block;
  margin-top: clamp(8px, 1.2vw, 14px);
  font-size: 0.86em;
  font-style: normal;
  opacity: 0.75;
  line-height: 1.5;
}

/* Multi-image grid (19.05.26): used by figures that carry a
   data-lightbox-images attribute (comma-separated image URLs).
   Currently the VotF curlew tile uses this to open the four
   narrator portraits in one view. 2x2 grid; each image scaled to
   fit its cell with object-fit: contain so the full artwork is
   visible. Mobile keeps the 2x2 layout since each tile is small. */
.lightbox__media--multi {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: clamp(6px, 1vw, 12px);
  width: 100%;
  max-height: 80vh;
}
.lightbox__media--multi img {
  width: 100%;
  height: 100%;
  max-height: 38vh;
  object-fit: contain;
  background: rgba(0, 0, 0, 0.25);
  border-radius: 4px;
}

/* ---------- Close button (18.05.26: 33% smaller per user) ---------- */
.lightbox__close {
  position: absolute;
  top: 0;
  right: 0;
  transform: translate(50%, -50%);
  width: 30px;
  height: 30px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0;
  border: 0;
  border-radius: 999px;
  background: #FFFFFF;
  color: #0F1419;
  cursor: pointer;
  z-index: 2;
  -webkit-tap-highlight-color: transparent;
  transition: background-color 160ms ease, color 160ms ease;
}
.lightbox__close:hover,
.lightbox__close:focus-visible {
  background: var(--accent);
  color: #FFFFFF;
}
.lightbox__close:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}
.lightbox__close svg {
  width: 14px;
  height: 14px;
  display: block;
}

/* ---------- Prev / next navigation (18.05.26 revised) ----------
   Shown when the opened lightbox figure belongs to a navigable group
   (currently only the BtM era figures). Hidden by default via the
   `hidden` attribute; lightbox.js toggles them on/off per group.
   Positioned ON the image (left/right inset 12px) per user direction.
   No pill background - just a white arrow glyph with drop-shadow for
   contrast against varied image content. Hover/focus flips to accent. */
.lightbox__nav {
  position: absolute;
  top: 50%;
  transform: translateY(-50%);
  width: 44px;
  height: 44px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0;
  border: 0;
  background: transparent;
  color: #FFFFFF;
  filter: drop-shadow(0 1px 3px rgba(0, 0, 0, 0.6));
  cursor: pointer;
  z-index: 2;
  -webkit-tap-highlight-color: transparent;
  transition: color 160ms ease;
}
.lightbox__nav:hover,
.lightbox__nav:focus-visible {
  color: var(--accent);
}
.lightbox__nav:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}
.lightbox__nav svg {
  width: 28px;
  height: 28px;
  display: block;
}
.lightbox__nav--prev { left: 12px; }
.lightbox__nav--next { right: 12px; }
.lightbox__nav[hidden] { display: none; }

/* ---------- BtM era-specific visibility ----------
   The BtM card stacks three era figures at the same position, each with
   data-lightbox. Only the active era's image is visually present
   (opacity 1); the other two sit at opacity 0 in the same space. We
   suppress the info-icon on the inactive eras so they don't pick up tab
   focus or stack three triggers behind the visible one. */
.et-card--btm .btm-stage__figure .lightbox-trigger {
  visibility: hidden;
}
.et-card--btm[data-era="1"] .btm-stage__figure[data-era="1"] .lightbox-trigger,
.et-card--btm[data-era="2"] .btm-stage__figure[data-era="2"] .lightbox-trigger,
.et-card--btm[data-era="3"] .btm-stage__figure[data-era="3"] .lightbox-trigger {
  visibility: visible;
}

/* ---------- Body lock ----------
   Prevents background scroll while the lightbox is open. */
body.lightbox-open {
  overflow: hidden;
}

/* ---------- Narrow viewport tuning ---------- */
@media (max-width: 576px) {
  .lightbox {
    padding: var(--s-3);
  }
  .lightbox-trigger {
    width: 26px;
    height: 26px;
    right: 10px;
    bottom: 10px;
  }
  .lightbox-trigger svg {
    width: 24px;
    height: 24px;
  }
  /* Tighten nav insets at narrow widths. */
  .lightbox__nav--prev { left: 6px; }
  .lightbox__nav--next { right: 6px; }
  .lightbox__nav { width: 36px; height: 36px; }
  .lightbox__nav svg { width: 22px; height: 22px; }
}