/* ============================================================
   UNTIL THE LAST STAR — interface layer
   Two voices: Bodoni Moda (display) · Martian Mono (telemetry)
   Opacity system: 100 active · 55 secondary · 30 resting · 12 hairline
   ============================================================ */

:root {
  --void: #08070F;
  --dusk: #10122A;
  --paper: #EDE9E0;
  --ember: #E4B85C;
  --op-active: 1;
  --op-secondary: 0.55;
  --op-resting: 0.3;
  --op-hairline: 0.12;
  --mono: 'Martian Mono', 'Courier New', monospace;
  --serif: 'Bodoni Moda', 'Didot', 'Times New Roman', serif;
  --track-h: 3200vh;
}

@media (max-width: 768px) {
  :root { --track-h: 2300vh; }
}

* { box-sizing: border-box; }

html {
  background: var(--dusk);
  scroll-behavior: auto; /* jumps are custom-eased in JS */
}

body {
  margin: 0;
  background: var(--dusk);
  color: var(--paper);
  font-family: var(--mono);
  overflow-x: hidden;
  touch-action: manipulation; /* taps are interactions — never double-tap zoom */
}

/* ---- scroll track (the timeline) ---- */
#track { height: var(--track-h); pointer-events: none; }

/* ---- scene canvas ---- */
#scene {
  position: fixed; inset: 0; width: 100%; height: 100%;
  display: block; z-index: 1;
}

/* ---- shared micro voice ---- */
.micro {
  font-family: var(--mono);
  font-size: 10px;
  font-weight: 400;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--paper);
  line-height: 1.6;
}
.dim { opacity: var(--op-resting); }

/* ---- preloader ---- */
#pre-line {
  width: min(320px, 60vw); height: 1px;
  background: rgba(237, 233, 224, var(--op-hairline));
}
#pre-fill {
  width: 0%; height: 100%;
  background: var(--ember);
  transition: width 0.3s ease;
}
#pre-wordmark { opacity: var(--op-secondary); margin: 0; }
#pre-status { margin: 0; }

/* ---- narrative layer ---- */
#narrative {
  position: fixed; inset: 0; z-index: 3;
  pointer-events: none;
}

#title-lockup {
  position: absolute; inset: 0;
  display: flex; flex-direction: column;
  align-items: center; justify-content: center;
  text-align: center;
  transition: opacity 0.4s ease;
}
#title-lockup h1 {
  margin: 0;
  font-family: var(--serif);
  font-weight: 500;
  font-optical-sizing: auto;
  font-size: clamp(3.2rem, 16.5vh, 12.5rem);
  line-height: 0.98;
  letter-spacing: 0.045em;
  color: var(--paper);
}
#title-lockup .line { display: block; }
#title-lockup .italic { font-style: italic; font-weight: 400; }
#subtitle { margin-top: 3.2rem; }

.epoch-text {
  position: absolute; inset: 0;
  display: flex; flex-direction: column;
  justify-content: center;
  /* left padding clears the epoch index; right stays tighter */
  padding: 0 8vw 0 clamp(180px, 15vw, 260px);
  opacity: 0;
  visibility: hidden;
  /* separation from bright scenes without a visible scrim */
  text-shadow: 0 0 26px rgba(8, 7, 15, 0.65), 0 1px 4px rgba(8, 7, 15, 0.5);
}
.epoch-text.visible { visibility: visible; opacity: 1; }
.epoch-text h2 {
  margin: 0 0 2.4rem;
  font-family: var(--serif);
  font-weight: 500;
  font-size: clamp(1.9rem, 7.5vh, 5.2rem);
  line-height: 1.02;
  letter-spacing: 0.03em;
  max-width: 14ch;
}
.epoch-text .caption {
  margin: 0 0 1.5rem;
  font-size: 13px;
  line-height: 1.9;
  letter-spacing: 0.06em;
  max-width: 38ch;
  opacity: 0;
  transform: translateY(10px);
  transition: opacity 0.9s ease, transform 0.9s ease;
}
.epoch-text .caption.on { opacity: var(--op-secondary); transform: none; }
.epoch-text h2 {
  opacity: 0; transform: translateY(14px);
  transition: opacity 1.1s ease, transform 1.1s ease;
}
.epoch-text.visible h2 { opacity: 1; transform: none; }

/* right-aligned variants keep long journeys compositionally varied */
.epoch-text.align-right { align-items: flex-end; text-align: right; }

/* ---- chrome ---- */
#chrome { position: fixed; inset: 0; z-index: 4; pointer-events: none; }
#chrome > * { pointer-events: auto; }

#wordmark {
  position: absolute; top: 28px; left: 32px;
  text-decoration: none;
  opacity: var(--op-resting);
  transition: opacity 0.3s ease;
}
#wordmark:hover, #wordmark:focus-visible { opacity: var(--op-secondary); }

/* epoch index — the entire navigation */
#epoch-index {
  position: absolute; left: 32px; top: 50%;
  transform: translateY(-50%);
  display: flex; flex-direction: column; gap: 14px;
  border-left: 1px solid rgba(237, 233, 224, var(--op-hairline));
  padding-left: 16px;
}
#epoch-index button {
  all: unset;
  pointer-events: auto;
  cursor: pointer;
  font-family: var(--mono);
  font-size: 9px;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--paper);
  opacity: var(--op-resting);
  transition: opacity 0.35s ease;
  position: relative;
  line-height: 1;
  padding: 2px 0;
  /* stays legible when a bright scene sweeps behind the index */
  text-shadow: 0 0 12px rgba(8, 7, 15, 0.9), 0 1px 3px rgba(8, 7, 15, 0.7);
}
#epoch-index button:hover { opacity: var(--op-secondary); }
#epoch-index button[aria-current='true'] { opacity: var(--op-active); }
#epoch-index button[aria-current='true']::before {
  content: '';
  position: absolute; left: -17px; top: 50%;
  width: 2px; height: 12px;
  transform: translateY(-50%);
  background: var(--ember);
}

#year-readout {
  position: absolute; left: 32px; bottom: 28px;
  margin: 0;
  opacity: var(--op-secondary);
  font-variant-numeric: tabular-nums;
  white-space: nowrap;
}
#year-readout sup { font-size: 0.65em; }

#sound-toggle {
  all: unset;
  pointer-events: auto; /* all:unset re-inherits #chrome's none — restore it */
  position: absolute; right: 32px; bottom: 28px;
  cursor: pointer;
  font-family: var(--mono);
  font-size: 10px;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--paper);
  opacity: var(--op-resting);
  transition: opacity 0.3s ease;
}
#sound-toggle:hover, #sound-toggle:focus-visible { opacity: var(--op-secondary); }

#scroll-whisper {
  position: absolute; left: 50%; bottom: 34px;
  transform: translateX(-50%);
  display: flex; flex-direction: column; align-items: center; gap: 10px;
  transition: opacity 1.2s ease;
}
#scroll-whisper.gone { opacity: 0 !important; }
#whisper-line {
  width: 1px; height: 34px;
  background: linear-gradient(rgba(237, 233, 224, 0.4), transparent);
  animation: whisper-drain 2.6s ease-in-out infinite;
}
@keyframes whisper-drain {
  0% { transform: scaleY(0); transform-origin: top; }
  55% { transform: scaleY(1); transform-origin: top; }
  100% { transform: scaleY(1) translateY(8px); opacity: 0; }
}

/* Gargantua owns the right of the frame and its disc band crosses the text
   column — this epoch gets the soft scrim on desktop too */
#epoch-long-night::before {
  content: '';
  position: absolute;
  inset: 0;
  opacity: 0;
  transition: opacity 0.9s ease;
  background: radial-gradient(
    ellipse 60% 46% at 24% 50%,
    rgba(8, 7, 15, 0.32) 0%,
    rgba(8, 7, 15, 0.2) 45%,
    transparent 72%
  );
}
#epoch-long-night.visible::before { opacity: 1; }

/* focus — id-level selectors so all:unset resets can't swallow the ring */
:focus-visible,
#epoch-index button:focus-visible,
#sound-toggle:focus-visible {
  outline: 1px solid var(--ember);
  outline-offset: 4px;
}

/* ---- custom cursor ---- */
#cursor {
  position: fixed; z-index: 10;
  mix-blend-mode: screen; /* the light passes over UI text without hiding it */
  width: 10px; height: 10px; border-radius: 50%;
  background: var(--ember);
  box-shadow: 0 0 14px 2px rgba(228, 184, 92, 0.45);
  pointer-events: none;
  transform: translate(-50%, -50%);
  left: 0; top: 0;
  opacity: 0;
  transition: opacity 0.4s ease;
}
body.has-pointer #cursor { opacity: 1; }
body.has-pointer.keyboard-nav #cursor { opacity: 0; }
/* after the last star dies, the light you carried is the only one left */
body.after-extinction #cursor {
  width: 13px; height: 13px;
  background: var(--ember) !important;
  box-shadow: 0 0 26px 7px rgba(228, 184, 92, 0.65);
  transition: opacity 0.4s ease, box-shadow 2.5s ease, width 2.5s ease, height 2.5s ease;
}
@media (hover: hover) and (pointer: fine) {
  body.has-pointer { cursor: none; }
  body.has-pointer a, body.has-pointer button { cursor: none; }
}

/* the last light (touch / keyboard / still endings) */
#ending-light {
  position: fixed; z-index: 9;
  width: 12px; height: 12px; border-radius: 50%;
  background: var(--ember);
  box-shadow: 0 0 18px 4px rgba(228, 184, 92, 0.5);
  pointer-events: none;
  transform: translate(-50%, -50%);
  animation: ember-breathe 3.2s ease-in-out infinite;
}
@keyframes ember-breathe {
  0%, 100% { box-shadow: 0 0 18px 4px rgba(228, 184, 92, 0.5); }
  50% { box-shadow: 0 0 26px 7px rgba(228, 184, 92, 0.7); }
}

/* ---- credits (final frame only; ui.js toggles .visible) ---- */
#credits {
  position: fixed; z-index: 4;
  left: 50%; bottom: 30px;
  transform: translateX(-50%);
  display: flex; gap: 2.2em;
  width: max-content;
  white-space: nowrap;
  opacity: 0;
  pointer-events: none;
  transition: opacity 1.4s ease;
}
#credits.visible { opacity: var(--op-resting); pointer-events: auto; }
#credits a, #credits span {
  color: var(--paper); text-decoration: none;
  font-size: 9px; letter-spacing: 0.22em; text-transform: uppercase;
}
#credits a:hover { color: var(--ember); }

/* ---- still mode ---- */
#still { position: fixed; inset: 0; z-index: 2; }
.still-frame {
  position: absolute; inset: 0;
  opacity: 0;
  transition: opacity 0.45s ease;
}
.still-frame.active { opacity: 1; }
.still-frame canvas { position: absolute; inset: 0; width: 100%; height: 100%; }
body.still-mode #scene { display: none; }
body.still-mode #cursor { display: none; }

@media (prefers-reduced-motion: reduce) {
  .still-frame { transition: none; }
  #whisper-line { animation: none; }
  #ending-light { animation: none; }
  .epoch-text h2, .epoch-text .caption { transition: none; }
}

/* ---- debug ---- */
#debug {
  position: fixed; top: 28px; right: 32px; z-index: 20;
  text-align: right;
  opacity: 0.7;
  font-variant-numeric: tabular-nums;
  white-space: pre;
}

/* ---- noscript ---- */
.noscript {
  position: fixed; inset: 0; z-index: 200;
  display: flex; align-items: center; justify-content: center;
  background: var(--dusk); color: var(--paper);
  font-family: var(--mono); font-size: 12px; line-height: 2;
  padding: 10vw; text-align: center;
}

/* ---- mobile ---- */
@media (max-width: 768px) {
  #wordmark { top: 20px; left: 20px; font-size: 9px; }
  #epoch-index { left: 12px; padding-left: 10px; gap: 12px; }
  /* collapse to ticks: hide label text except active */
  #epoch-index button { font-size: 0; }
  #epoch-index button::after {
    content: ''; display: block; width: 12px; height: 2px;
    background: var(--paper); opacity: 0.6;
  }
  #epoch-index button[aria-current='true'] { font-size: 8px; }
  #epoch-index button[aria-current='true']::after { display: none; }
  #epoch-index button[aria-current='true']::before { left: -11px; }
  #year-readout { left: 20px; bottom: 20px; font-size: 9px; }
  #sound-toggle { right: 20px; bottom: 20px; font-size: 9px; }
  #credits { bottom: 56px; gap: 1.4em; }
  #credits a, #credits span { font-size: 8px; }
  /* narrow screens: one alignment, padded clear of the widest active index
     label, and bottom-anchored — hero objects ride high (portrait pitch),
     text lives in the darker lower third */
  .epoch-text, .epoch-text.align-right {
    align-items: flex-start;
    text-align: left;
    justify-content: flex-end;
    padding: 0 6vw 15vh clamp(130px, 35vw, 152px);
  }
  .epoch-text h2 {
    font-size: clamp(1.5rem, 8vw, 2.4rem);
    max-width: 100%;
    overflow-wrap: break-word;
  }
  .epoch-text .caption { font-size: 12px; max-width: 100%; }
  /* bright scenes fill the whole narrow viewport — captions need more separation */
  .epoch-text {
    text-shadow: 0 0 16px rgba(8, 7, 15, 0.95), 0 0 40px rgba(8, 7, 15, 0.75),
      0 1px 3px rgba(8, 7, 15, 0.85);
  }
  .epoch-text .caption.on { opacity: 0.85; }
  /* text-protection scrim: a soft local darkening behind the caption zone,
     only while the epoch's text is on screen. ~30% at its heart, feathered
     wide so it never reads as a panel. */
  .epoch-text::before {
    content: '';
    position: absolute;
    inset: 0;
    opacity: 0;
    transition: opacity 0.9s ease;
    background: radial-gradient(
      ellipse 130% 50% at 42% 72%,
      rgba(8, 7, 15, 0.34) 0%,
      rgba(8, 7, 15, 0.22) 45%,
      transparent 72%
    );
  }
  .epoch-text.visible::before { opacity: 1; }
  /* HOME is bottom-anchored — its scrim sits low with the text */
  #epoch-home::before {
    background: radial-gradient(
      ellipse 130% 46% at 42% 76%,
      rgba(8, 7, 15, 0.34) 0%,
      rgba(8, 7, 15, 0.22) 45%,
      transparent 72%
    );
  }
  /* HOME: the sun owns the narrow frame's center — anchor the text low, over the arm */
  #epoch-home {
    justify-content: flex-end;
    padding-bottom: 12vh;
  }
  #title-lockup h1 { font-size: clamp(2.6rem, 13vw, 5rem); letter-spacing: 0.03em; }
  #subtitle { margin-top: 2rem; padding: 0 8vw; font-size: 8px; }
}