/* ---------- CatListen tokens — warm ivory + signature olive ---------- */
:root {
  --paper: #faf8f2; /* soft paper — page canvas */
  --surface: #f5f1e8; /* warm ivory — cards and panels */
  --ink: #292723;
  --muted: #8d897f;
  --accent: #687342; /* signature olive — primary actions, active, progress */
  --terra: #cc785c; /* terracotta — journey progress, in-progress state (brief-specified) */
  --sage: #8a9a86; /* sage — journey progress, completed state (brief-specified) */
  --accent-deep: oklch(from var(--accent) calc(l - 0.07) c h);
  --border: oklch(85.5% 0.012 88); /* warm hairline, derived from ivory + ink */
  /* five worlds — muted editorial tints; deep line tones derived, never invented */
  --w1: #e5e7d6;
  --w1-ink: oklch(from var(--w1) calc(l - 0.42) calc(c * 2 + 0.02) h); /* 日常星球 · sage */
  --w2: #e8dad5;
  --w2-ink: oklch(from var(--w2) calc(l - 0.42) calc(c * 2 + 0.02) h); /* 银幕剧场 · burgundy */
  --w3: #dde5e5;
  --w3-ink: oklch(from var(--w3) calc(l - 0.4) calc(c * 2 + 0.025) h); /* 世界漫游 · faded blue */
  --w4: #e9ded4;
  --w4-ink: oklch(from var(--w4) calc(l - 0.42) calc(c * 2 + 0.02) h); /* 人间观察 · terracotta */
  --w5: #e9e4ce;
  --w5-ink: oklch(from var(--w5) calc(l - 0.44) calc(c * 2 + 0.02) h); /* 思维实验室 · ochre */
  /* deep-space derivations — the whole cosmos is the faded-blue tint, darkened down
       (w3 hue ≈ 197; shifts pull it toward indigo / muted violet, never neon) */
  --space: oklch(
    from var(--w3) calc(l * 0.27) calc(c * 2.4 + 0.012) calc(h + 72)
  ); /* deep indigo base */
  --space-deep: oklch(
    from var(--w3) calc(l * 0.18) calc(c * 2 + 0.008) calc(h + 66)
  ); /* darker depths — the quiet left */
  --space-haze: oklch(
    from var(--w3) calc(l * 0.56) calc(c * 2.6 + 0.016) calc(h + 78)
  ); /* nebula mid tone */
  --space-glow: oklch(
    from var(--w3) calc(l * 0.63) calc(c * 2.6 + 0.02) calc(h + 88)
  ); /* nebula inner glow, muted violet */
  --space-mist: oklch(
    from var(--w3) calc(l * 0.57) calc(c * 2.4 + 0.022) calc(h + 104)
  ); /* restrained lavender, nebula only */
  --space-blush: oklch(
    from var(--w3) calc(l * 0.54) calc(c * 2.2 + 0.018) calc(h + 182)
  ); /* warm gray-pink, nebula only */
  --star: oklch(from var(--w3) calc(l * 0.95) calc(c * 0.7) calc(h + 30)); /* pale dust light */
  --star-warm: oklch(
    from var(--paper) calc(l - 0.04) calc(c + 0.04) calc(h - 12)
  ); /* small warm tether star, like a balloon */
  --suit: oklch(
    from var(--paper) calc(l - 0.12) calc(c + 0.004) calc(h - 4)
  ); /* soft warm cream-gray spacesuit, flat */
  --suit-shade: oklch(
    from var(--paper) calc(l - 0.3) calc(c + 0.008) calc(h + 4)
  ); /* suit shadow tones */
  --cream: oklch(
    from var(--paper) calc(l - 0.07) calc(c + 0.008) calc(h + 6)
  ); /* warm cream — ears, tail, backpack */
  --cream-shade: oklch(
    from var(--paper) calc(l - 0.22) calc(c + 0.01) calc(h + 8)
  ); /* backpack shading, strap lines */
  --cat-dark: oklch(
    from var(--w3) calc(l * 0.23) calc(c * 1.6 + 0.008) calc(h + 44)
  ); /* cat head silhouette */
  --hero-paper: oklch(from var(--paper) calc(l - 0.03) c h); /* type on the dark scene */
  --hero-dim: oklch(
    from var(--w3) calc(l - 0.14) calc(c + 0.008) calc(h + 24)
  ); /* small caps on dark, ≥4.5:1 */
  --serif: 'Noto Serif SC', 'Songti SC', 'STSong', serif;
  --sans: 'PingFang SC', system-ui, -apple-system, 'Segoe UI', 'Helvetica Neue', Arial, sans-serif;
}
* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}
html {
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}
body {
  background: var(--paper);
  color: var(--ink);
  font-family: var(--sans);
  font-size: 15px;
  line-height: 1.7;
}
::selection {
  background: var(--accent);
  color: var(--paper);
}
a {
  color: inherit;
  text-decoration: none;
}
a:focus-visible,
button:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 3px;
  border-radius: 2px;
}

/* ---------- small-caps editorial label ---------- */
.caps {
  font-family: var(--sans);
  font-size: 11px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--muted);
}
/* ---------- world identity bindings ---------- */
.w1 {
  --wa: var(--w1);
  --wad: var(--w1-ink);
}
.w2 {
  --wa: var(--w2);
  --wad: var(--w2-ink);
}
.w3 {
  --wa: var(--w3);
  --wad: var(--w3-ink);
}
.w4 {
  --wa: var(--w4);
  --wad: var(--w4-ink);
}
.w5 {
  --wa: var(--w5);
  --wad: var(--w5-ink);
}

/* ---------- back link — single quiet way home ---------- */
.back-link {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  min-height: 44px;
  font-size: 13px;
  color: var(--muted);
  letter-spacing: 0.02em;
  transition: color 0.15s ease;
}
.back-link:hover {
  color: var(--accent);
}

/* ======================= 1 · world hero — full-viewport quiet cosmos =======================
     one boundary-less nebula drifting center-right, a cat astronaut passing below it;
     paper type sits in the continuous deep-space band on the left
     (World Visual System — text safe zone: the entire left side, dark and evenly quiet) */
.wh {
  position: relative;
  height: 100vh;
  min-height: 640px;
  background: var(--space-deep);
  overflow: hidden;
}
.wh-bg-wrap {
  position: absolute;
  inset: 0;
}
.wh-art-src {
  position: absolute;
} /* scene source — referenced by both viewport crops */
.wh-bg {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  display: block;
  transform: scale(1.06); /* headroom for the slow scroll drift */
}
.wh-bg-m {
  display: none;
} /* portrait crop, woken only below 768px */
/* atmospheric scrim — a whisper of deeper space behind the left type column,
     so the whole six-line block rests on evenly quiet darkness */
.wh-scrim {
  position: absolute;
  inset: 0;
  background: linear-gradient(
    to right,
    oklch(from var(--space-deep) l c h / 0.5),
    oklch(from var(--space-deep) l c h / 0.16) 44%,
    oklch(from var(--space-deep) l c h / 0) 64%
  );
}
/* bottom dissolve — deep space feathers out into the paper canvas, no horizon line */
.wh-fade {
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 240px;
  z-index: 1;
  pointer-events: none;
  background: linear-gradient(
    to bottom,
    oklch(from var(--space) l c h / 0),
    oklch(from var(--space-deep) l c h / 0.38) 46%,
    var(--paper)
  );
}
.wh-back {
  position: absolute;
  top: 24px;
  left: clamp(24px, 4vw, 48px);
  z-index: 3;
  color: var(--hero-paper);
  opacity: 0.66;
}
.wh-back:hover {
  color: var(--hero-paper);
  opacity: 1;
}
.wh-text {
  position: absolute;
  left: clamp(24px, 5vw, 64px);
  max-width: 640px;
  bottom: clamp(
    240px,
    32vh,
    340px
  ); /* left-lower-center: optical center ≈ 48–54% of hero height, clear of the 240px dissolve */
  z-index: 2;
  color: var(--hero-paper);
}
.wh-eyebrow {
  font-size: 11px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--hero-dim);
}
.wh-text h1 {
  font-family: var(--serif);
  font-weight: 600;
  font-size: clamp(48px, 6.8vw, 100px);
  line-height: 1.3;
  letter-spacing: 0;
  margin-top: 18px;
}
.wh-text .en-title {
  font-size: 13px;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: oklch(from var(--w3) calc(l - 0.06) calc(c + 0.012) calc(h + 30));
  margin-top: 8px;
}
.wh-line {
  margin-top: 20px;
  font-family: var(--serif);
  font-size: 17px;
  color: var(--hero-paper);
  opacity: 0.88;
}
.wh-line-sub {
  margin-top: 6px;
  font-size: 10px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--hero-dim);
}
/* restrained text CTA — hairline underline, arrow nudge only */
.wh-cta {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  margin-top: 26px;
  min-height: 44px;
  font-size: 14px;
  letter-spacing: 0.02em;
  color: var(--hero-paper);
  border-bottom: 1px solid oklch(from var(--hero-paper) l c h / 0.45);
  padding-bottom: 4px;
  transition: border-color 0.15s ease;
}
.wh-cta .arr {
  display: inline-block;
  transition: transform 0.2s ease;
}
.wh-cta:hover {
  border-bottom-color: var(--hero-paper);
}
.wh-cta:hover .arr {
  transform: translateX(4px);
}

/* slow life inside the dark — star twinkle and the cat's weightless drift, off when reduced motion */
@media (prefers-reduced-motion: no-preference) {
  .wh .tw {
    animation: star-twinkle 6s ease-in-out infinite;
  }
  .wh .tw2 {
    animation: star-twinkle 8.5s ease-in-out 1.4s infinite;
  }
  .wh .tw3 {
    animation: star-twinkle 11s ease-in-out 3s infinite;
  }
  .wh .cat-float {
    animation: cat-drift 16s ease-in-out infinite alternate;
  }
}
@keyframes star-twinkle {
  0%,
  100% {
    opacity: 0.3;
  }
  50% {
    opacity: 0.75;
  }
}
@keyframes cat-drift {
  from {
    transform: translate(0, 0);
  }
  to {
    transform: translate(9px, -13px);
  }
}

/* ======================= 2 · editor's note — quiet magazine prose ======================= */
.intro {
  margin-top: 88px;
}
.intro p {
  margin-top: 18px;
  font-size: 16px;
  line-height: 1.9;
  color: var(--ink);
  max-width: 38em;
  text-align: justify;
  text-justify: inter-character;
}

/* ---------- section headers ---------- */
.sec {
  margin-top: 96px;
}
.sec-head {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  border-bottom: 1px solid var(--border);
  padding-bottom: 16px;
  margin-bottom: 40px;
}
.sec-title {
  display: flex;
  align-items: baseline;
  gap: 16px;
}
.sec-title h2 {
  font-family: var(--serif);
  font-weight: 600;
  font-size: 30px;
  line-height: 1.35;
  letter-spacing: 0;
}

/* ---------- tablet 768–1199: icons-only rail, hero boundary, 2-col grid ----------
     HERO BOUNDARY (hard rule): hero height + intro + section head > 100vh, so no journey
     cover can enter the first viewport — only the section title / hairline may peek.
     Verified at 768×1024 (cards at ~1140px) and 1024×768 (min-height 560 → cards at ~950px). */
@media (max-width: 1199px) {
  .content {
    padding: 0 40px 88px;
  }
  .wh {
    height: 70vh;
    min-height: 560px;
  }
  .wh-text {
    top: 44%;
    bottom: auto;
    transform: translateY(-44%);
  }
  .intro {
    margin-top: 88px;
  }
  .sec {
    margin-top: 88px;
  }
}

/* ---------- mobile <768: full-bleed immersive hero, type in the upper quiet dark ----------
     first screen is entering the universe itself — edge to edge, no frame; paper type floats
     in the quiet upper dark, the nebula and the drifting cat stay in the middle-lower field */
@media (max-width: 767px) {
  .content {
    padding: 0 20px 72px;
  }
  .wh {
    height: 94vh;
    min-height: 560px;
  }
  .wh-back {
    top: 14px;
    left: 20px;
  }
  /* TOP UI SAFE AREA (hard rule): the top ~9% of the mobile hero belongs to navigation
       (back link occupies 14–58px) — the six-line text block always starts below it:
       world metadata ≈ 10–12% from the hero top, the title group ≈ 15–18% */
  .wh-text {
    top: clamp(68px, 10.5vh, 132px);
    bottom: auto;
    transform: none;
    left: 20px;
    right: 20px;
    max-width: none;
  }
  .wh-text h1 {
    font-size: clamp(34px, 9vw, 44px);
    margin-top: 12px;
  }
  /* a whisper of deeper dark behind the upper type — the nebula glow never crosses the words */
  .wh-scrim {
    background: linear-gradient(
      to bottom,
      oklch(from var(--space-deep) l c h / 0.55),
      oklch(from var(--space-deep) l c h / 0.18) 44%,
      oklch(from var(--space-deep) l c h / 0) 62%
    );
  }
  .wh-fade {
    height: 140px;
  }
  .wh-bg {
    display: none;
  }
  .wh-bg.wh-bg-m {
    display: block;
  } /* portrait crop: quiet dark above, nebula and cat below */
  .intro {
    margin-top: 64px;
  }
  .sec {
    margin-top: 64px;
  }
  .sec-head {
    flex-wrap: wrap;
    gap: 12px;
    margin-bottom: 28px;
  }
  .sec-title h2 {
    font-size: 24px;
  }
}

.content {
  max-width: 1184px;
  margin: 0 auto;
  padding: 0 56px 96px;
}

@media (max-width: 1199px) {
  .content {
    padding: 0 40px 88px;
  }
}
@media (max-width: 767px) {
  .content {
    padding: 0 22px 72px;
  }
}