/* ============================================================
   Kennen · 数字灵魂  ·  Design tokens (per §2)
   ============================================================ */

@import url('https://fonts.googleapis.com/css2?family=Newsreader:ital,opsz,wght@0,6..72,400;0,6..72,500;0,6..72,600;1,6..72,400;1,6..72,500&family=IBM+Plex+Mono:ital,wght@0,400;0,500;1,400&family=Noto+Serif+SC:wght@400;500;600;700&family=Noto+Sans+SC:wght@300;400;500&display=swap');

:root {
  /* color ----------------------------------------------------- */
  --dusk:        #4E5180;   /* Future Dusk — primary */
  --dusk-glow:   #7B7EE0;   /* glow */
  --ink:         #0C0E1D;   /* 暮色墨 — background */
  --ink-2:       #14152360; /* faint panel wash */
  --moon:        #E9E7F2;   /* 冷月白 — text */
  --moon-pure:   #FBFAFF;   /* pure white — key titles only */
  --amber:       #E3A062;   /* 暖琥珀 — soul-fire, <8% of site */
  --mono-blue:   #7E80A6;   /* 暮蓝 — secondary / mono text */
  --line:        #23243a;   /* hairline divider */

  /* type ------------------------------------------------------ */
  --serif:   'Newsreader', 'Noto Serif SC', Georgia, serif;
  --mono:    'IBM Plex Mono', ui-monospace, 'SFMono-Regular', monospace;
  --zh-serif:'Noto Serif SC', 'Songti SC', serif;
  --zh-sans: 'Noto Sans SC', 'PingFang SC', -apple-system, sans-serif;

  /* rhythm ---------------------------------------------------- */
  --maxw: 1180px;
  --gut: clamp(22px, 5vw, 80px);
  --section-y: clamp(120px, 17vh, 220px);
  --ease: cubic-bezier(.22,.61,.36,1);
}

/* reset ------------------------------------------------------- */
* { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }
@media (prefers-reduced-motion: reduce) { html { scroll-behavior: auto; } }

body {
  background: var(--ink);
  color: var(--moon);
  font-family: var(--zh-sans);
  font-weight: 300;
  line-height: 1.7;
  letter-spacing: .01em;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
  overflow-x: hidden;
}

/* deep field gradient under the whole page (very subtle) */
body::before {
  content: "";
  position: fixed; inset: 0;
  background:
    radial-gradient(120% 80% at 50% -10%, #181a2e 0%, transparent 55%),
    radial-gradient(90% 60% at 50% 120%, #15162600 0%, transparent 60%);
  pointer-events: none; z-index: 0;
}

/* ====================  i18n visibility  ===================== */
.en { display: none; }
html[data-lang="en"] .zh { display: none; }
html[data-lang="en"] .en { display: revert; }
/* inline variants keep inline */
span.en, a.en, em.en, strong.en, b.en { display: none; }
html[data-lang="en"] span.zh, html[data-lang="en"] a.zh,
html[data-lang="en"] em.zh, html[data-lang="en"] strong.zh, html[data-lang="en"] b.zh { display: none; }
html[data-lang="en"] span.en, html[data-lang="en"] a.en,
html[data-lang="en"] em.en, html[data-lang="en"] strong.en, html[data-lang="en"] b.en { display: inline; }

/* When EN active, latin display gets the serif; when ZH, titles use zh-serif */
html[data-lang="en"] { font-family: var(--serif); }

/* ====================  shared atoms  ======================== */
.wrap { max-width: var(--maxw); margin: 0 auto; padding-inline: var(--gut); }
.section { position: relative; z-index: 1; padding-block: var(--section-y); }

.kicker {
  font-family: var(--mono);
  font-size: clamp(11px, 1vw, 13px);
  letter-spacing: .34em;
  text-transform: uppercase;
  color: var(--mono-blue);
  display: inline-block;
}

/* titles */
.h-display {
  font-family: var(--serif);
  font-weight: 400;
  font-optical-sizing: auto;
  line-height: 1.06;
  letter-spacing: -.012em;
  color: var(--moon-pure);
}
html:not([data-lang="en"]) .h-display {
  font-family: var(--zh-serif);
  font-weight: 500;
  letter-spacing: .02em;
  line-height: 1.18;
}

.lede {
  font-family: var(--zh-sans);
  font-weight: 300;
  color: var(--moon);
  opacity: .82;
}
html[data-lang="en"] .lede { font-family: var(--serif); font-weight: 400; }

.amber { color: var(--amber); }
.glow-txt { color: var(--dusk-glow); }
/* cool moon-white with a Future-Dusk blue halo — for key title phrases */
.lumin {
  color: var(--moon-pure);
  text-shadow:
    0 0 .5em color-mix(in oklab, var(--dusk-glow) 52%, transparent),
    0 0 1.4em color-mix(in oklab, var(--dusk) 42%, transparent);
}

/* German signature — italic serif, constant, never toggled */
.de {
  font-family: var(--serif);
  font-style: italic;
  color: var(--mono-blue);
  letter-spacing: .015em;
}

/* the anchor-fact line (mono dusk-blue, ✅ / ◇) */
.anchor {
  font-family: var(--mono);
  font-size: clamp(12px, 1.05vw, 14px);
  line-height: 1.6;
  color: var(--mono-blue);
  letter-spacing: .01em;
}
.anchor .live { color: var(--dusk-glow); }
.anchor .next { color: var(--mono-blue); opacity: .8; }

/* hairline */
.rule { height: 1px; background: var(--line); border: 0; }

/* ====================  reveal animation  ==================== */
.reveal { opacity: 0; transform: translateY(22px); transition: opacity 1.1s var(--ease), transform 1.1s var(--ease); }
.reveal.in { opacity: 1; transform: none; }
@media (prefers-reduced-motion: reduce) {
  .reveal { opacity: 1; transform: none; transition: none; }
}

/* soul canvas wrapper */
.soul { position: relative; width: 100%; }
.soul canvas {
  display: block; width: 100%; height: 100%;
  -webkit-mask-image: radial-gradient(closest-side, #000 78%, transparent 100%);
  mask-image: radial-gradient(closest-side, #000 78%, transparent 100%);
}
/* the structural diagram needs its full frame — no edge fade */
.vision-soul canvas { -webkit-mask-image: none; mask-image: none; }