/* ============================================================================
   Photo ring — styles for ring.js.

   Every colour and face is a custom property so the ring can sit on the
   white tennis page, the warm-paper portfolio, or a black stage without a
   second stylesheet. Defaults are for a dark stage.

   The contract a host page may set on .ring (defaults in brackets):

     Materials
       --ring-paper          the print border and the back of each card (#f3f1ec)
       --ring-muted          hint and pause text, no-JS captions (#8d8a82)
       --ring-focus          the focus ring on the card in front, and on the
                             pause button (#fff)
       --ring-mono           the monospace stack for hint, pause and captions
       --ring-radius         corner of card faces, the lightbox image and the
                             no-JS grid; the photograph inside a card takes a
                             concentric, smaller corner (3px)
       --ring-shade-color    what a card fades toward as it turns away or
                             recedes: black darkens it, a paper colour pales it
                             into the page instead (#000)

     Lightbox (dark in both themes unless the host says otherwise)
       --ring-lb-backdrop    the veil over the page (rgba(8, 8, 9, .94))
       --ring-lb-ink         the caption (#e9e6de)
       --ring-lb-muted       the "3 / 14" count (#a9a59c)
       --ring-lb-btn-border  button rings, at least 3:1 on the backdrop (#8a877f)
       --ring-lb-btn-fg      button icons, and the button ring on hover (#fff)
       --ring-lb-focus       the focus ring inside the lightbox, at least 3:1
                             on the backdrop (#fff)

   The stage itself carries no focus ring: the one indicator is the outline
   on the card in front, so a host's global :focus-visible outline is
   switched off on the stage here, with enough weight to win.
   ========================================================================== */

.ring {
  --ring-bg: #0b0b0c;
  --ring-paper: #f3f1ec;
  --ring-ink: #1a1a17;
  --ring-muted: #8d8a82;
  --ring-focus: #ffffff;
  --ring-mono: ui-monospace, "Cascadia Mono", "Segoe UI Mono", "SF Mono", Menlo, Consolas, monospace;
  --ring-radius: 3px;
  --ring-shade-color: #000;
  --ring-lb-backdrop: rgba(8, 8, 9, .94);
  --ring-lb-ink: #e9e6de;
  --ring-lb-muted: #a9a59c;
  --ring-lb-btn-border: #8a877f;
  --ring-lb-btn-fg: #fff;
  --ring-lb-focus: #fff;
  --ring-ease: cubic-bezier(.22, 1, .36, 1);
  position: relative;
}

/* ---------------------------------------------------------------- Stage --
   The stage carries the perspective; the cards do not share a 3D context,
   so the browser never tries to resolve their overlap. ring.js sets each
   card's z-index from its depth instead, and sizes the wheel to the stage:
   it reads the perspective and its origin from here. */
.ring-stage {
  position: relative;
  height: clamp(17rem, 58vw, 34rem);
  perspective: 2000px;
  perspective-origin: 50% 30%;
  overflow: hidden;
  cursor: grab;
  touch-action: pan-y;          /* a vertical swipe still scrolls the page */
  user-select: none;
  -webkit-user-select: none;
  -webkit-tap-highlight-color: transparent;
  outline: none;
}
.ring-stage.is-dragging { cursor: grabbing; }
.ring .ring-stage:focus-visible { outline: none; box-shadow: none; }

/* ----------------------------------------------------------------- Card --
   Each card is a small print: a paper edge around the photograph, on both
   faces, so the wheel reads as pictures all the way round. Cards share a
   height (--ch, on the stage) and take their own photograph's width (--cw,
   on each card). */
.ring-card {
  position: absolute;
  left: 50%; top: var(--cy, 44%);
  width: var(--cw, 140px);
  height: var(--ch, 187px);
  margin: calc(var(--ch, 187px) / -2) 0 0 calc(var(--cw, 140px) / -2);
  transform-style: preserve-3d;
  will-change: transform;
}
.ring-face {
  position: absolute; inset: 0;
  border-radius: var(--ring-radius);
  overflow: hidden;
  background: var(--ring-paper);
  /* The border is a share of the height, not the width, so a landscape
     print has the same edge as a portrait one. */
  padding: calc(var(--ch, 187px) * .03);
  backface-visibility: hidden;
  -webkit-backface-visibility: hidden;
}
.ring-back { transform: rotateY(180deg); }
.ring-front img, .ring-back img {
  display: block;
  width: 100%; height: 100%;
  object-fit: cover;
  border-radius: max(min(1px, var(--ring-radius)), calc(var(--ring-radius) - 4px));
  pointer-events: none;
  -webkit-user-drag: none;
}
.ring-play {
  position: absolute; left: 50%; top: 50%;
  width: clamp(1.5rem, calc(var(--ch, 187px) * .2), 2.75rem);
  height: auto;
  aspect-ratio: 1;
  transform: translate(-50%, -50%);
  color: #fff;
  pointer-events: none;
}
/* Light falls from the front: ring.js sets --shade per card each frame. */
.ring-face::after {
  content: "";
  position: absolute; inset: 0;
  background: var(--ring-shade-color);
  opacity: var(--shade, 0);
  pointer-events: none;
}
.ring .ring-stage:focus-visible .ring-card.is-featured .ring-front {
  outline: 2px solid var(--ring-focus);
  outline-offset: 2px;
}

/* ------------------------------------------------ Hint, pause, status -- */
.ring-controls {
  display: flex; flex-wrap: wrap; align-items: center; justify-content: center;
  column-gap: .5rem;
  margin-top: .35rem;
}
.ring-hint {
  margin: 0;
  text-align: center;
  font-family: var(--ring-mono);
  font-size: .75rem;
  letter-spacing: .04em;
  color: var(--ring-muted);
}
.ring-pause {
  min-width: 2.75rem; min-height: 2.75rem;    /* 44px */
  padding: 0 .6rem;
  border: 0;
  background: none;
  font-family: var(--ring-mono);
  font-size: .75rem;
  letter-spacing: .04em;
  color: var(--ring-muted);
  text-decoration: underline;
  text-decoration-thickness: 1px;
  text-underline-offset: .3em;
  text-decoration-color: color-mix(in srgb, currentColor 45%, transparent);
  cursor: pointer;
  transition: text-decoration-color .2s var(--ring-ease);
}
.ring-pause:hover { text-decoration-color: currentColor; }
.ring .ring-pause:focus-visible { outline: 2px solid var(--ring-focus); outline-offset: -.35rem; border-radius: 2px; }
.ring-pause[hidden] { display: none; }
.ring-status {
  position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px;
  overflow: hidden; clip: rect(0, 0, 0, 0); white-space: nowrap; border: 0;
}

/* ------------------------------------------------------------- Lightbox --
   Close sits in the bar with prev and next, not floated above the dialog,
   where a short window cut it off. The image leaves room for its caption
   and the bar within the window's height. */
.ring-lightbox {
  width: min(92vw, 44rem);
  max-height: 92vh;
  padding: 0;
  border: 0;
  background: transparent;
  color: var(--ring-lb-ink);
  overflow: visible;
}
.ring-lightbox::backdrop { background: var(--ring-lb-backdrop, rgba(8, 8, 9, .94)); }
.ring-lightbox[open] { animation: ring-in .35s var(--ring-ease); }
@keyframes ring-in { from { opacity: .4; transform: translateY(8px) scale(.985); } }

.ring-lightbox-figure { margin: 0; display: grid; justify-items: center; gap: .7rem; }
.ring-lightbox-figure > img,
.ring-lightbox-figure > video {
  display: block;
  max-width: 100%;
  max-height: calc(92vh - 8rem);
  max-height: calc(92dvh - 8rem);
  width: auto; height: auto;
  border: 6px solid var(--ring-paper);
  border-radius: var(--ring-radius);
  background: var(--ring-paper);
}
.ring-lightbox-figure > [hidden] { display: none; }
.ring-lightbox-caption {
  font-family: var(--ring-mono);
  font-size: .8125rem;
  line-height: 1.5;
  letter-spacing: .02em;
  color: var(--ring-lb-ink);
  text-align: center;
  max-width: 36rem;
}
.ring-lightbox-bar {
  display: flex; align-items: center; justify-content: center; gap: 1rem;
  margin-top: .6rem;
}
.ring-lightbox-count {
  font-family: var(--ring-mono);
  font-size: .75rem;
  color: var(--ring-lb-muted);
  min-width: 3.5rem;
  text-align: center;
  font-variant-numeric: tabular-nums;
}
.ring-lightbox-btn {
  display: grid; place-items: center;
  width: 2.75rem; height: 2.75rem;      /* 44px */
  padding: 0;
  border: 1px solid var(--ring-lb-btn-border);
  border-radius: 50%;
  background: transparent;
  color: var(--ring-lb-btn-fg);
  cursor: pointer;
  transition: border-color .25s var(--ring-ease), background-color .25s var(--ring-ease);
}
.ring-lightbox-btn:hover {
  border-color: var(--ring-lb-btn-fg);
  background: rgba(255, 255, 255, .1);
  background: color-mix(in srgb, var(--ring-lb-btn-fg) 10%, transparent);
}
.ring-lightbox-btn svg { width: 18px; height: 18px; display: block; }
/* Close is a different kind of act from turning a page, so it stands a
   little apart from the pair it follows. */
.ring-lightbox-close { margin-left: .75rem; }
.ring .ring-lightbox :focus-visible { outline: 2px solid var(--ring-lb-focus); outline-offset: 3px; }

/* ------------------------------------------------------- No-JS fallback --
   Without the script the source list is a plain captioned grid. */
.ring-source {
  list-style: none; margin: 0; padding: 0;
  display: grid; grid-template-columns: repeat(auto-fill, minmax(9rem, 1fr));
  gap: 1rem;
}
.ring-source figure { margin: 0; }
.ring-source img {
  display: block; width: 100%; height: auto;
  aspect-ratio: 3 / 4; object-fit: cover;
  border-radius: var(--ring-radius);
}
.ring-source figcaption {
  margin-top: .4rem;
  font-family: var(--ring-mono);
  font-size: .75rem;
  color: var(--ring-muted);
}
.ring.is-live .ring-source { display: none; }

@media (prefers-reduced-motion: reduce) {
  .ring-lightbox[open] { animation: none; }
  .ring-lightbox-btn, .ring-pause { transition: none; }
}