/* KML Ambient Player – reusable rendering shell */

:root {
  --ambient-fade: 4000ms;
  --ambient-overlay: 0.52;
  --ambient-kanji: clamp(5rem, 18vw, 11rem);
  --ambient-text: #f5f0e6;
  --ambient-muted: rgba(245, 240, 230, 0.72);
  --ambient-accent: #d4bc82;
  --ken-burns-duration: 180s;
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

html,
body {
  margin: 0;
  height: 100%;
  overflow: hidden;
  background: #0e0d0b;
  color: var(--ambient-text);
  font-family: "Noto Serif JP", "Yuji Mai", Georgia, serif;
}

.ambient-root {
  position: fixed;
  inset: 0;
  isolation: isolate;
}

/* ── Background layers (video or image fallback) ── */

.ambient-bg {
  position: absolute;
  inset: 0;
  overflow: hidden;
}

.ambient-bg-layer {
  position: absolute;
  inset: -8%;
  opacity: 0;
  transition: opacity var(--ambient-fade) ease-in-out;
  will-change: opacity, transform;
}

.ambient-bg-layer.is-active {
  opacity: 1;
}

.ambient-bg-layer video,
.ambient-bg-layer img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
  transform-origin: var(--image-transform-origin, center center);
}

.ambient-bg-layer img.ken-burns {
  animation: ken-burns var(--ken-burns-duration, 120s) ease-in-out infinite alternate;
}

.ambient-root.is-paused .ambient-bg-layer img.ken-burns {
  animation-play-state: paused;
}

@keyframes ken-burns {
  from {
    transform: scale(calc(var(--image-scale, 1) * 1)) translate(0, 0);
  }
  to {
    transform: scale(calc(var(--image-scale, 1) * 1.12)) translate(-2%, -1.5%);
  }
}

.ambient-overlay {
  position: absolute;
  inset: 0;
  background:
    radial-gradient(ellipse at center, rgba(14, 13, 11, 0.15) 0%, rgba(14, 13, 11, 0.75) 100%),
    linear-gradient(to bottom, rgba(14, 13, 11, 0.35), rgba(14, 13, 11, 0.65));
  opacity: var(--ambient-overlay);
  pointer-events: none;
}

/* ── Foreground content ── */

.ambient-stage {
  position: relative;
  z-index: 2;
  display: grid;
  grid-template-rows: 1fr auto auto;
  align-items: end;
  justify-items: center;
  height: 100%;
  padding: clamp(1rem, 4vw, 2.5rem);
  gap: clamp(0.75rem, 2vw, 1.5rem);
  text-align: center;
}

.ambient-kanji-block {
  align-self: center;
  opacity: 0;
  transform: translateY(12px);
  transition:
    opacity var(--ambient-fade) ease-in-out,
    transform var(--ambient-fade) ease-in-out;
}

.ambient-kanji-block.is-visible {
  opacity: 1;
  transform: translateY(0);
}

.ambient-kanji {
  font-family: "Yuji Syuku", "Noto Serif JP", serif;
  font-size: var(--ambient-kanji);
  font-weight: 400;
  line-height: 1;
  letter-spacing: 0.04em;
  text-shadow:
    0 0 24px rgba(0, 0, 0, 0.55),
    0 4px 18px rgba(0, 0, 0, 0.45);
}

.ambient-keyword {
  margin-top: 0.35rem;
  font-size: clamp(0.95rem, 2.2vw, 1.15rem);
  letter-spacing: 0.18em;
  text-transform: lowercase;
  color: var(--ambient-accent);
  opacity: 0.9;
}

.ambient-image-wrap {
  width: min(420px, 72vw);
  opacity: 0;
  transform: scale(0.97);
  transition:
    opacity var(--ambient-fade) ease-in-out,
    transform var(--ambient-fade) ease-in-out;
}

.ambient-image-wrap.is-visible {
  opacity: 1;
  transform: scale(1);
}

.ambient-image-wrap img {
  width: 100%;
  height: auto;
  display: block;
  border-radius: 10px;
  box-shadow:
    0 8px 32px rgba(0, 0, 0, 0.45),
    0 0 0 1px rgba(255, 255, 255, 0.08);
}

.ambient-verses {
  max-width: min(680px, 92vw);
  opacity: 0;
  transform: translateY(10px);
  transition:
    opacity var(--ambient-fade) ease-in-out,
    transform var(--ambient-fade) ease-in-out;
}

.ambient-verses.is-visible {
  opacity: 1;
  transform: translateY(0);
}

.ambient-verse-jp {
  font-size: clamp(1.05rem, 2.6vw, 1.45rem);
  line-height: 1.75;
  margin: 0 0 0.65rem;
  text-shadow: 0 2px 12px rgba(0, 0, 0, 0.65);
}

.ambient-verse-jp ruby rt {
  font-size: 0.55em;
  opacity: 0;
  transition: opacity 0.3s ease;
}

.ambient-verse-jp.show-furigana ruby rt {
  opacity: 0.85;
}

.ambient-verse-en {
  margin: 0;
  font-size: clamp(0.9rem, 2vw, 1.05rem);
  line-height: 1.6;
  color: var(--ambient-muted);
  font-style: italic;
  white-space: pre-line;
}

/* ── Study mode (guided flashcards) ── */

.ambient-root.is-study .ambient-image-wrap {
  display: none;
}

.ambient-root.is-study .ambient-verses {
  opacity: 1;
  transform: none;
}

.ambient-root.is-study .ambient-kanji-block,
.ambient-root.is-study .ambient-verse-jp {
  opacity: 0;
  transform: none;
  transition: opacity var(--ambient-fade) ease-in-out;
}

.ambient-root.is-study .ambient-keyword {
  opacity: 0;
  transition: opacity var(--ambient-fade) ease-in-out;
}

.ambient-root.is-study .ambient-kanji-block.is-visible,
.ambient-root.is-study .ambient-verse-jp.is-visible {
  opacity: 1;
}

.ambient-root.is-study .ambient-keyword.is-visible {
  opacity: 0.92;
}

.ambient-root.is-study .ambient-verse-en {
  display: none;
}

.ambient-root.is-study .ambient-bg-layer.is-intro img {
  object-fit: contain;
  animation: none;
}

.ambient-autoplay-gate {
  position: absolute;
  inset: 0;
  z-index: 20;
  display: grid;
  place-items: center;
  margin: 0;
  padding: 2rem;
  border: 0;
  background: rgba(14, 13, 11, 0.72);
  color: rgba(245, 240, 230, 0.82);
  font: inherit;
  font-size: clamp(0.95rem, 2.4vw, 1.15rem);
  letter-spacing: 0.12em;
  text-transform: uppercase;
  cursor: pointer;
  backdrop-filter: blur(4px);
  opacity: 0;
  transition: opacity 600ms ease-in-out;
}

.ambient-autoplay-gate.is-visible {
  opacity: 1;
}

.ambient-autoplay-gate:focus-visible {
  outline: 1px solid rgba(212, 188, 130, 0.55);
  outline-offset: -6px;
}

.ambient-root.is-study.is-foreground-exiting .ambient-kanji-block,
.ambient-root.is-study.is-foreground-exiting .ambient-keyword,
.ambient-root.is-study.is-foreground-exiting .ambient-verse-jp {
  transition: opacity var(--ambient-study-exit-fade, 800ms) ease-in-out;
}

/* ── Chrome / controls ── */

.ambient-chrome {
  position: absolute;
  z-index: 3;
  inset: 0;
  pointer-events: none;
}

.ambient-title {
  position: absolute;
  top: clamp(0.75rem, 2vw, 1.25rem);
  left: 50%;
  transform: translateX(-50%);
  font-size: 0.78rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: rgba(245, 240, 230, 0.55);
  pointer-events: none;
}

.ambient-controls {
  position: absolute;
  bottom: clamp(0.75rem, 2vw, 1.25rem);
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  gap: 0.5rem;
  pointer-events: auto;
}

.ambient-controls button {
  appearance: none;
  border: 1px solid rgba(245, 240, 230, 0.22);
  background: rgba(14, 13, 11, 0.55);
  color: var(--ambient-text);
  border-radius: 999px;
  padding: 0.45rem 0.95rem;
  font: inherit;
  font-size: 0.82rem;
  cursor: pointer;
  backdrop-filter: blur(6px);
}

.ambient-controls button:hover {
  background: rgba(14, 13, 11, 0.75);
}

.ambient-progress {
  position: absolute;
  bottom: 0;
  left: 0;
  height: 3px;
  width: 0%;
  background: linear-gradient(90deg, transparent, var(--ambient-accent), transparent);
  transition: width 120ms linear;
}

.ambient-root.is-manual .ambient-progress {
  display: none;
}

/* ── Presentation / OBS capture mode ── */

.ambient-root.is-capture .ambient-chrome {
  display: none;
}

.ambient-root.is-capture .ambient-loading {
  color: transparent;
  user-select: none;
}

.ambient-root.is-capture .ambient-autoplay-gate {
  color: transparent;
  background: transparent;
  backdrop-filter: none;
  letter-spacing: 0;
}

.ambient-root.is-capture.is-cursor-idle,
.ambient-root.is-capture.is-cursor-idle * {
  cursor: none !important;
}

html.is-capture-doc,
html.is-capture-doc body {
  overflow: hidden;
}

.ambient-capture-curtain {
  position: absolute;
  inset: 0;
  z-index: 12;
  background: #0e0d0b;
  opacity: 0;
  pointer-events: none;
  transition: opacity var(--ambient-capture-fade, 5000ms) ease-out;
}

.ambient-capture-curtain.is-visible {
  opacity: 1;
}

.ambient-root.is-presentation-ended .ambient-stage,
.ambient-root.is-presentation-ended .ambient-bg {
  visibility: hidden;
}

/* ── Gallery Seal Ending ── */

.ambient-root.is-gallery-seal-holding .ambient-overlay {
  transition: opacity var(--ambient-gallery-hold-darken, 4000ms) ease-in-out
    var(--ambient-gallery-hold-darken-delay, 1500ms);
  opacity: 0.88;
}

.ambient-root.is-study.is-verse-exiting .ambient-verse-jp {
  transition: opacity var(--ambient-gallery-verse-fade, 1800ms) ease-in-out;
  opacity: 0 !important;
}

.ambient-root.is-study.is-kanji-exiting .ambient-kanji-block,
.ambient-root.is-study.is-kanji-exiting .ambient-keyword {
  transition: opacity var(--ambient-gallery-kanji-fade, 1800ms) ease-in-out;
  opacity: 0 !important;
}

.ambient-root.is-gallery-seal-fading .ambient-overlay {
  transition: opacity var(--ambient-gallery-fade-to-black, 4000ms) ease-in-out;
  opacity: 0;
}

.ambient-root.is-gallery-seal-fading .ambient-bg-layer.is-active img.ken-burns {
  animation-play-state: running;
}

.ambient-root.is-gallery-seal-active .ambient-overlay {
  opacity: 0;
}

.ambient-gallery-seal {
  position: fixed;
  inset: 0;
  z-index: 15;
  display: flex;
  align-items: center;
  justify-content: center;
  background: transparent;
  opacity: 1;
  pointer-events: none;
}

.ambient-gallery-seal img {
  width: min(56vw, 400px);
  height: min(56vw, 400px);
  object-fit: cover;
  display: block;
  clip-path: circle(42% at 50% 50%);
  filter: drop-shadow(0 6px 28px rgba(0, 0, 0, 0.45));
  will-change: opacity, transform;
  opacity: 0;
  transform: scale(0.97);
  transition:
    opacity var(--ambient-gallery-seal-fade, 4000ms) ease-in-out,
    transform var(--ambient-gallery-seal-fade, 4000ms) ease-in-out;
}

.ambient-gallery-seal.is-visible img {
  opacity: 1;
  transform: scale(1);
}

.ambient-root.is-presentation-ended.is-gallery-seal-ending .ambient-gallery-seal {
  visibility: visible;
}

.ambient-root.is-presentation-ended.is-gallery-seal-ending .ambient-gallery-seal img {
  opacity: 1;
  transform: scale(1);
}

.ambient-status {
  position: absolute;
  top: clamp(0.75rem, 2vw, 1.25rem);
  right: clamp(0.75rem, 2vw, 1.25rem);
  font-size: 0.72rem;
  color: rgba(245, 240, 230, 0.45);
  pointer-events: none;
}

.ambient-loading,
.ambient-error {
  position: absolute;
  inset: 0;
  display: grid;
  place-items: center;
  z-index: 10;
  background: #0e0d0b;
  padding: 2rem;
  text-align: center;
}

.ambient-error {
  color: #e8b4b4;
}

.ambient-hidden {
  display: none !important;
}

@media (prefers-reduced-motion: reduce) {
  .ambient-bg-layer img.ken-burns {
    animation: none;
    transform: scale(var(--image-scale, 1));
  }

  .ambient-bg-layer,
  .ambient-kanji-block,
  .ambient-image-wrap,
  .ambient-verses {
    transition-duration: 0.01ms !important;
  }
}