/* SohoArchTimes — full-screen slideshow
   Black stage, 16:9 letterboxed presentation frame, preserved image aspect.
   Minimal, restrained, professional. */

:root {
  --bg: #000;
  --fg: #f3f1ec;            /* warm off-white */
  --fg-muted: #b8b4ab;
  --fg-faint: #7d7a73;
  --rule: rgba(243, 241, 236, 0.22);
  --hud-shadow: 0 1px 2px rgba(0,0,0,0.85);
  --transition: 240ms cubic-bezier(0.22, 1, 0.36, 1);
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  padding: 0;
  height: 100%;
  background: var(--bg);
  color: var(--fg);
  font-family: "Satoshi", "General Sans", system-ui, -apple-system, "Segoe UI", sans-serif;
  font-weight: 400;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow: hidden;
  cursor: default;
}

body.hide-cursor, body.hide-cursor * { cursor: none !important; }

.stage {
  position: fixed;
  inset: 0;
  background: #000;
  display: grid;
  place-items: center;
  overflow: hidden;
}

/* Full-screen frame: images scale to the screen bounds while preserving aspect ratio.
   Any unused area stays black. */
.frame {
  position: relative;
  width: 100vw;
  height: 100vh;
  max-width: 100vw;
  max-height: 100vh;
  margin: auto;
  background: #000;
  overflow: hidden;
  --letterbox-band: 0px;
  --caption-offset: clamp(14px, 2.2vh, 28px);
  --hud-offset: clamp(14px, 2.2vh, 28px);
  --letterbox-pad: clamp(8px, 1vh, 14px);
  --caption-bottom: var(--caption-offset);
  --hud-bottom: var(--hud-offset);
}

/* The two image layers — one shown, one preloaded */
.slide-img {
  position: absolute;
  left: 50%;
  top: 50%;
  transform: translate(-50%, -50%);
  max-width: 100%;
  max-height: calc(100% - (var(--letterbox-band) * 2));
  object-fit: contain;         /* preserve aspect ratio inside active frame */
  object-position: center;
  background: #000;            /* unused field stays black */
  opacity: 0;                  /* JS controls opacity */
  z-index: 1;
  transition: opacity 3000ms linear;
  user-select: none;
  pointer-events: none;
  /* Crisper scaling on high-DPI displays */
  image-rendering: -webkit-optimize-contrast;
  will-change: opacity;
}
.slide-img[data-state="visible"] { opacity: 1; }
/* The incoming layer sits ON TOP: it fades in while the layer beneath
   fades out at the same speed — a symmetric crossfade, never black. */
.slide-img[data-top] { z-index: 2; }

/* Bottom-left metadata caption */
.caption {
  position: absolute;
  left: clamp(14px, 1.6vw, 30px);
  bottom: var(--caption-bottom);
  z-index: 10;
  max-width: min(62%, 900px);
  font-family: "General Sans", "Satoshi", system-ui, sans-serif;
  font-size: clamp(12px, 1.05vw, 15px);
  line-height: 1.45;
  letter-spacing: 0.01em;
  color: var(--fg);
  text-shadow: var(--hud-shadow);
  opacity: 0;
  transform: translateY(4px);
  transition: opacity 600ms ease, transform 600ms ease;
}
.caption[data-state="in"] {
  opacity: 0.94;
  transform: translateY(0);
}

.caption .cap-title {
  font-weight: 500;
  letter-spacing: 0;
}
.caption .cap-arch  { color: var(--fg); }
.caption .cap-year,
.caption .cap-loc   { color: var(--fg-muted); font-weight: 400; }
.caption .cap-sep   {
  display: inline-block;
  margin: 0 0.55em;
  color: var(--fg-faint);
  font-weight: 300;
}
.caption .cap-title:empty,
.caption .cap-arch:empty,
.caption .cap-year:empty,
.caption .cap-loc:empty { display: none; }
/* Hide adjacent separators when a field is empty */
.caption .cap-title:empty + .cap-sep,
.caption .cap-arch:empty  + .cap-sep,
.caption .cap-year:empty  + .cap-sep { display: none; }
.caption .cap-sep:first-child,
.caption .cap-sep + .cap-sep { display: none; }

/* Bottom-right HUD (brand + counter) — extremely discreet */
.hud {
  position: absolute;
  right: clamp(14px, 1.6vw, 30px);
  bottom: var(--hud-bottom);
  z-index: 10;
  display: flex;
  align-items: baseline;
  gap: 0.55em;
  font-family: "General Sans", "Satoshi", system-ui, sans-serif;
  font-size: clamp(11px, 0.85vw, 13px);
  font-weight: 400;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--fg-muted);
  text-shadow: var(--hud-shadow);
  opacity: 0;
  transition: opacity 600ms ease;
}
.hud[data-state="in"] { opacity: 0.7; }
.hud-brand { color: var(--fg); letter-spacing: 0.16em; text-transform: none; }
.hud-sep   { color: var(--fg-faint); }
.hud-count { font-variant-numeric: tabular-nums; color: var(--fg-muted); }

/* Tiny page-refresh button after the counter — no larger than the digits */
.hud-refresh {
  display: inline-flex;
  align-items: center;
  align-self: center;
  padding: 0;
  border: 0;
  background: none;
  font: inherit;
  line-height: 1;
  color: var(--fg-muted);
  cursor: pointer;
  transition: color var(--transition);
}
.hud-refresh:hover,
.hud-refresh:focus-visible { color: var(--fg); }
.hud-refresh svg { display: block; filter: drop-shadow(0 1px 2px rgba(0,0,0,0.85)); }
.hud-refresh[data-busy] { color: var(--fg); }
.hud-refresh[data-busy] svg { animation: hud-refresh-spin 1.1s linear infinite; }
@keyframes hud-refresh-spin { to { transform: rotate(360deg); } }

/* Language toggle (RU / EN) — same discreet weight as the counter */
.hud-lang {
  display: inline-flex;
  align-items: center;
  align-self: center;
  gap: 0.28em;
  margin-left: 0.15em;
  padding: 0;
  border: 0;
  background: none;
  font: inherit;
  letter-spacing: 0.06em;
  line-height: 1;
  cursor: pointer;
  text-shadow: var(--hud-shadow);
}
.hud-lang-opt { color: var(--fg-faint); transition: color var(--transition); }
.hud-lang-opt[data-active] { color: var(--fg); }
.hud-lang:hover .hud-lang-opt { color: var(--fg-muted); }
.hud-lang:hover .hud-lang-opt[data-active] { color: var(--fg); }
.hud-lang-sep { color: var(--fg-faint); }

/* Loader (visible only when waiting for an image) */
.loader {
  position: absolute;
  left: 50%;
  top: 50%;
  transform: translate(-50%, -50%);
  z-index: 8;
  display: none;
  align-items: center;
  gap: 0.7em;
  font-family: "General Sans", system-ui, sans-serif;
  font-size: 12px;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--fg-muted);
}
.loader[data-state="on"] { display: inline-flex; }
.loader-dot {
  width: 6px; height: 6px; border-radius: 50%;
  background: var(--fg);
  animation: pulse 1.4s ease-in-out infinite;
}
@keyframes pulse {
  0%, 100% { opacity: 0.25; transform: scale(0.9); }
  50%      { opacity: 1;     transform: scale(1.15); }
}

/* Discreet controls — fade in on pointer move, fade out after idle */
.controls {
  position: absolute;
  left: 50%;
  bottom: clamp(56px, 7vh, 96px);
  transform: translateX(-50%);
  z-index: 20;
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 8px 10px;
  background: rgba(8,8,8,0.55);
  border: 1px solid rgba(255,255,255,0.06);
  border-radius: 999px;
  backdrop-filter: blur(8px) saturate(120%);
  -webkit-backdrop-filter: blur(8px) saturate(120%);
  opacity: 0;
  pointer-events: none;
  transition: opacity 220ms ease;
}
.controls[data-state="show"] {
  opacity: 1;
  pointer-events: auto;
}
.ctl {
  appearance: none;
  background: transparent;
  border: 0;
  color: var(--fg);
  width: 34px; height: 34px;
  font-size: 16px;
  font-family: inherit;
  border-radius: 999px;
  cursor: pointer;
  display: inline-grid;
  place-items: center;
  transition: background 160ms ease, transform 160ms ease;
}
.ctl:hover  { background: rgba(255,255,255,0.08); }
.ctl:active { transform: scale(0.94); }
.ctl:focus-visible {
  outline: 1px solid rgba(255,255,255,0.6);
  outline-offset: 2px;
}

/* First-launch hint */
.hint {
  position: absolute;
  left: 50%;
  top: clamp(20px, 4vh, 40px);
  transform: translateX(-50%);
  z-index: 30;
  font-family: "General Sans", system-ui, sans-serif;
  font-size: 12px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--fg-muted);
  opacity: 0;
  transition: opacity 500ms ease;
  pointer-events: none;
}
.hint[data-state="show"] { opacity: 0.55; }

/* Smaller viewports — keep caption readable, hide HUD to avoid collision */
@media (max-width: 900px) {
  .hud { display: none !important; }
}

@media (max-width: 640px) {
  .frame {
    --caption-offset: 10px;
    --hud-offset: 10px;
    --letterbox-pad: 8px;
  }
  .caption {
    font-size: 12px;
    max-width: calc(100% - 24px);
    left: 12px;
  }
  .controls { bottom: 80px; }
}

/* Narrow portrait — keep only the caption and give it clear breathing room */
@media (max-aspect-ratio: 1/1) and (max-width: 900px) {
  .caption {
    left: 12px;
    right: 12px;
    max-width: calc(100% - 24px);
    bottom: 10px;
    font-size: 12px;
    line-height: 1.35;
  }
  .hud { display: none !important; }
}

@media (prefers-reduced-motion: reduce) {
  .slide-img { transition-duration: 200ms !important; }
}