/* ==========================================================================
   sicaintelligence.com.cn — design system
   Zero external requests: system fonts only (works without Google Fonts/CDN).
   ========================================================================== */

/* ---------- tokens ---------- */
:root {
  --font-display: "Songti SC", "Noto Serif SC", "Source Han Serif SC", "STSong",
    "SimSun", Georgia, "Times New Roman", serif;
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
    "Hiragino Sans GB", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
  --font-mono: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas,
    "Liberation Mono", monospace;

  --max: 1080px;
  --radius: 14px;
  --radius-sm: 8px;
  --dur: 0.22s;
}

html[data-theme="dark"] {
  --bg: #070a0c;
  --bg-soft: #0b1013;
  --panel: #0e1418;
  --panel-2: #121a1f;
  --line: rgba(255, 255, 255, 0.10);
  --line-strong: rgba(255, 255, 255, 0.18);
  --fg: #e9eef2;
  --fg-soft: #b9c4cd;
  --muted: #7d8b96;
  --accent: #47e0c8;
  --accent-ink: #05201c;
  --accent-2: #ffc46b;
  --accent-3: #9db4ff;
  --grid: rgba(255, 255, 255, 0.045);
  --glow: rgba(71, 224, 200, 0.16);
  --shadow: 0 18px 48px rgba(0, 0, 0, 0.55);
  --quote-bg: rgba(71, 224, 200, 0.05);
  color-scheme: dark;
}

html[data-theme="light"] {
  --bg: #fbfbf9;
  --bg-soft: #f3f4f1;
  --panel: #ffffff;
  --panel-2: #f7f8f5;
  --line: rgba(16, 24, 32, 0.11);
  --line-strong: rgba(16, 24, 32, 0.22);
  --fg: #101619;
  --fg-soft: #35424c;
  --muted: #66727c;
  --accent: #0d8577;
  --accent-ink: #ffffff;
  --accent-2: #a76509;
  --accent-3: #3c53b8;
  --grid: rgba(16, 24, 32, 0.045);
  --glow: rgba(13, 133, 119, 0.10);
  --shadow: 0 14px 40px rgba(16, 24, 32, 0.10);
  --quote-bg: rgba(13, 133, 119, 0.05);
  color-scheme: light;
}

/* ---------- reset ---------- */
*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--fg);
  font-family: var(--font-sans);
  font-size: 16.5px;
  line-height: 1.78;
  letter-spacing: 0.006em;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}
img, svg { max-width: 100%; display: block; }
a { color: inherit; text-decoration: none; }
button { font: inherit; color: inherit; cursor: pointer; }
:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 3px;
  border-radius: 4px;
}
[hidden] { display: none !important; }

/* ---------- ambient background ---------- */
body::before {
  content: "";
  position: fixed;
  inset: 0;
  z-index: -2;
  background-image: linear-gradient(var(--grid) 1px, transparent 1px),
    linear-gradient(90deg, var(--grid) 1px, transparent 1px);
  background-size: 68px 68px;
  mask-image: radial-gradient(ellipse 90% 60% at 50% 0%, #000 12%, transparent 78%);
  -webkit-mask-image: radial-gradient(ellipse 90% 60% at 50% 0%, #000 12%, transparent 78%);
}
body::after {
  content: "";
  position: fixed;
  z-index: -1;
  top: -320px;
  left: 50%;
  width: 900px;
  height: 700px;
  transform: translateX(-50%);
  background: radial-gradient(circle, var(--glow) 0%, transparent 66%);
  pointer-events: none;
}

/* ---------- layout ---------- */
.wrap { width: 100%; max-width: var(--max); margin: 0 auto; padding: 0 24px; }
main { display: block; }
section { margin: 0 0 84px; }

.skip {
  position: absolute;
  left: -9999px;
  top: 0;
  background: var(--accent);
  color: var(--accent-ink);
  padding: 10px 16px;
  z-index: 99;
  border-radius: 0 0 var(--radius-sm) 0;
}
.skip:focus { left: 0; }

/* ---------- top bar ---------- */
.topbar {
  position: sticky;
  top: 0;
  z-index: 40;
  backdrop-filter: saturate(160%) blur(14px);
  -webkit-backdrop-filter: saturate(160%) blur(14px);
  background: color-mix(in srgb, var(--bg) 82%, transparent);
  border-bottom: 1px solid var(--line);
}
.topbar__in {
  display: flex;
  align-items: center;
  gap: 18px;
  height: 62px;
}
.brand { display: flex; align-items: center; gap: 10px; margin-right: auto; min-width: 0; }
.brand__mark {
  width: 30px; height: 30px; flex: none;
  border: 1px solid var(--line-strong);
  border-radius: 7px;
  display: grid; place-items: center;
  font-family: var(--font-mono);
  font-size: 12px; font-weight: 600;
  color: var(--accent);
  background: var(--panel);
}
.brand__txt { display: flex; flex-direction: column; line-height: 1.15; min-width: 0; }
.brand__name { font-size: 14.5px; font-weight: 650; letter-spacing: 0.01em; }
.brand__dom {
  font-family: var(--font-mono);
  font-size: 10.5px;
  color: var(--muted);
  white-space: nowrap; overflow: hidden; text-overflow: ellipsis;
}
.nav { display: flex; align-items: center; gap: 2px; }
.nav a {
  padding: 7px 11px;
  border-radius: var(--radius-sm);
  font-size: 14px;
  color: var(--fg-soft);
  white-space: nowrap;
  transition: background var(--dur), color var(--dur);
}
.nav a:hover { background: var(--panel-2); color: var(--fg); }
.nav a[aria-current="page"] { color: var(--accent); background: var(--panel-2); }

.ctrls { display: flex; align-items: center; gap: 8px; }
.btn-icon {
  width: 34px; height: 34px;
  display: grid; place-items: center;
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
  background: var(--panel);
  color: var(--fg-soft);
  transition: border-color var(--dur), color var(--dur), background var(--dur);
}
.btn-icon:hover { border-color: var(--line-strong); color: var(--fg); }
.lang {
  display: flex; align-items: center;
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
  background: var(--panel);
  overflow: hidden;
}
.lang button {
  border: 0; background: transparent;
  padding: 7px 10px;
  font-family: var(--font-mono);
  font-size: 11.5px; letter-spacing: 0.06em;
  color: var(--muted);
  transition: background var(--dur), color var(--dur);
}
.lang button[aria-pressed="true"] { background: var(--accent); color: var(--accent-ink); font-weight: 600; }
.lang button:hover:not([aria-pressed="true"]) { color: var(--fg); }

/* ---------- typography ---------- */
.eyebrow {
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--accent);
  margin: 0 0 16px;
  display: flex; align-items: center; gap: 10px;
}
.eyebrow::after {
  content: ""; flex: 1; height: 1px;
  background: linear-gradient(90deg, var(--line-strong), transparent);
}
h1, h2, h3 { font-family: var(--font-display); font-weight: 600; letter-spacing: 0.01em; }
h1 {
  font-size: clamp(2.6rem, 7.2vw, 4.15rem);
  line-height: 1.08;
  margin: 0 0 18px;
  letter-spacing: 0.02em;
}
h2 {
  font-size: clamp(1.45rem, 3.2vw, 1.95rem);
  line-height: 1.32;
  margin: 0 0 20px;
}
h3 { font-size: 1.12rem; line-height: 1.45; margin: 0 0 8px; }
p { margin: 0 0 18px; color: var(--fg-soft); }
p:last-child { margin-bottom: 0; }
strong { color: var(--fg); font-weight: 650; }
em { font-style: italic; }
code {
  font-family: var(--font-mono);
  font-size: 0.875em;
  background: var(--panel-2);
  border: 1px solid var(--line);
  border-radius: 5px;
  padding: 1px 6px;
  color: var(--accent);
}
.lede { font-size: 1.12rem; color: var(--fg-soft); max-width: 62ch; }
.mono { font-family: var(--font-mono); }
.muted { color: var(--muted); }
.rule { height: 1px; background: var(--line); border: 0; margin: 0; }

/* ---------- hero ---------- */
/* NOTE: only vertical padding here — a `padding` shorthand would clobber the
   horizontal gutter that .wrap provides when both classes sit on one element. */
.hero { padding-top: 88px; padding-bottom: 64px; }
.hero__name { display: flex; align-items: baseline; flex-wrap: wrap; gap: 14px; }
.hero__name .latin {
  font-family: var(--font-mono);
  font-size: clamp(0.85rem, 2vw, 1rem);
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--muted);
  font-weight: 400;
}
/* in English the romanisation is the name — don't print it twice */
html[data-lang="en"] .hero__name .latin { display: none; }
.hero__sub {
  font-size: 1.06rem;
  color: var(--fg-soft);
  max-width: 56ch;
  margin: 0 0 26px;
}
.tags { display: flex; flex-wrap: wrap; gap: 10px; margin: 0 0 30px; padding: 0; list-style: none; }
.tag {
  display: inline-flex; align-items: center; gap: 9px;
  border: 1px solid var(--line-strong);
  background: var(--panel);
  border-radius: 999px;
  padding: 8px 16px 8px 11px;
  font-size: 0.95rem;
  color: var(--fg);
  transition: border-color var(--dur), transform var(--dur), box-shadow var(--dur);
}
.tag:hover { border-color: var(--accent); transform: translateY(-2px); box-shadow: var(--shadow); }
.tag__i {
  font-family: var(--font-mono);
  font-size: 10px;
  color: var(--accent);
  border: 1px solid var(--line);
  border-radius: 999px;
  padding: 2px 7px;
}
.tag__en {
  font-family: var(--font-mono);
  font-size: 10.5px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--muted);
}

/* ---------- statement block ---------- */
.statement {
  font-family: var(--font-display);
  font-size: clamp(1.5rem, 4.4vw, 2.35rem);
  line-height: 1.45;
  color: var(--fg);
  border-left: 3px solid var(--accent);
  padding: 4px 0 4px 26px;
  margin: 0 0 26px;
  letter-spacing: 0.02em;
}
.statement--solo { border: 0; padding: 0; }

/* ---------- cards & grids ---------- */
.grid { display: grid; gap: 18px; }
.grid--3 { grid-template-columns: repeat(auto-fit, minmax(272px, 1fr)); }
.grid--2 { grid-template-columns: repeat(auto-fit, minmax(320px, 1fr)); }

.card {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 26px 24px;
  position: relative;
  transition: border-color var(--dur), transform var(--dur), box-shadow var(--dur);
}
.card:hover { border-color: var(--line-strong); box-shadow: var(--shadow); transform: translateY(-3px); }
.card__num {
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: 0.14em;
  color: var(--accent);
  margin: 0 0 14px;
  display: block;
}
.card h3 { color: var(--fg); }
.card p { font-size: 0.96rem; margin-bottom: 12px; }
.card ul { margin: 0; padding-left: 1.05em; color: var(--fg-soft); font-size: 0.95rem; }
.card li { margin-bottom: 7px; }
.card li::marker { color: var(--accent); }

/* belief-index cards: pin the CTA to the bottom so unequal copy still aligns */
a.card--link { display: flex; flex-direction: column; color: inherit; }
a.card--link .card__go {
  display: inline-flex; align-items: center; gap: 7px;
  margin-top: auto; padding-top: 18px;
  align-self: flex-start;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--accent);
}
a.card--link:hover .card__go { gap: 12px; }
.card__go span { transition: transform var(--dur); }

/* ---------- belief quote ---------- */
.belief-q {
  font-family: var(--font-display);
  font-size: 1.16rem;
  line-height: 1.7;
  color: var(--fg);
  margin: 0 0 10px;
}
.belief-src {
  font-family: var(--font-mono);
  font-size: 11.5px;
  color: var(--muted);
  letter-spacing: 0.05em;
}

/* ---------- prose ---------- */
.prose { max-width: 68ch; }
.prose h2 { margin-top: 46px; }
.prose h2:first-child { margin-top: 0; }
.prose ul, .prose ol { color: var(--fg-soft); padding-left: 1.15em; margin: 0 0 20px; }
.prose li { margin-bottom: 9px; }
.prose li::marker { color: var(--accent); }

.pull {
  margin: 30px 0;
  padding: 24px 26px;
  background: var(--quote-bg);
  border: 1px solid var(--line);
  border-left: 3px solid var(--accent);
  border-radius: 0 var(--radius) var(--radius) 0;
}
.pull p {
  font-family: var(--font-display);
  font-size: 1.1rem;
  line-height: 1.72;
  color: var(--fg);
  margin: 0 0 12px;
}
.pull .en {
  font-family: var(--font-sans);
  font-size: 1rem;
  color: var(--fg-soft);
  border-top: 1px dashed var(--line-strong);
  padding-top: 12px;
  margin-top: 4px;
}
.pull cite {
  display: block;
  font-style: normal;
  font-family: var(--font-mono);
  font-size: 11.5px;
  color: var(--muted);
  letter-spacing: 0.04em;
  margin-top: 12px;
}

.classic {
  font-family: var(--font-display);
  font-size: 1.14rem;
  line-height: 2.05;
  color: var(--fg);
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 28px 30px;
  margin: 0 0 22px;
  letter-spacing: 0.05em;
}

/* ---------- paper card ---------- */
.paper {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
  margin: 0 0 22px;
}
.paper__hd {
  display: flex; align-items: center; gap: 10px; flex-wrap: wrap;
  padding: 15px 24px;
  border-bottom: 1px solid var(--line);
  background: var(--panel-2);
}
.paper__kind {
  font-family: var(--font-mono);
  font-size: 10.5px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--accent-ink);
  background: var(--accent);
  border-radius: 999px;
  padding: 4px 11px;
  font-weight: 600;
}
.paper__kind--alt { background: var(--accent-2); }
.paper__kind--ghost { background: transparent; color: var(--muted); border: 1px solid var(--line-strong); }
.paper__bd { padding: 24px; }
.paper__title { font-size: 1.14rem; font-weight: 650; margin: 0 0 12px; line-height: 1.45; font-family: var(--font-sans); }
.paper__meta {
  font-family: var(--font-mono);
  font-size: 12px;
  line-height: 1.85;
  color: var(--muted);
  margin: 0 0 18px;
  word-break: break-word;
}
.paper__meta b { color: var(--fg-soft); font-weight: 500; }
.paper__links { display: flex; flex-wrap: wrap; gap: 10px; margin-top: 18px; }
.btn {
  display: inline-flex; align-items: center; gap: 8px;
  border: 1px solid var(--line-strong);
  background: var(--panel-2);
  border-radius: var(--radius-sm);
  padding: 9px 15px;
  font-size: 13.5px;
  font-family: var(--font-mono);
  color: var(--fg);
  transition: border-color var(--dur), background var(--dur), transform var(--dur);
}
.btn:hover { border-color: var(--accent); color: var(--accent); transform: translateY(-1px); }
.btn--solid { background: var(--accent); color: var(--accent-ink); border-color: var(--accent); font-weight: 600; }
.btn--solid:hover { color: var(--accent-ink); filter: brightness(1.08); }

/* ---------- misc blocks ---------- */
.note {
  border: 1px dashed var(--line-strong);
  border-radius: var(--radius);
  padding: 18px 20px;
  font-size: 0.92rem;
  color: var(--muted);
  background: transparent;
}
.note b { color: var(--fg-soft); }

.kv { margin: 0; padding: 0; }
.kv dt {
  font-family: var(--font-mono);
  font-size: 10.5px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--muted);
  margin: 0 0 4px;
}
.kv dd { margin: 0 0 18px; color: var(--fg); font-size: 0.98rem; }
.kv dd:last-child { margin-bottom: 0; }

.pager {
  display: flex; justify-content: space-between; gap: 16px; flex-wrap: wrap;
  border-top: 1px solid var(--line);
  padding-top: 24px;
  margin-top: 64px;
}
.pager a { font-size: 14px; color: var(--fg-soft); display: inline-flex; flex-direction: column; gap: 3px; }
.pager a:hover { color: var(--accent); }
.pager .lbl { font-family: var(--font-mono); font-size: 10.5px; letter-spacing: 0.14em; text-transform: uppercase; color: var(--muted); }

/* ---------- footer ---------- */
.foot {
  border-top: 1px solid var(--line);
  margin-top: 96px;
  padding: 40px 0 56px;
  font-size: 0.9rem;
  color: var(--muted);
}
.foot__grid { display: grid; gap: 26px; grid-template-columns: repeat(auto-fit, minmax(210px, 1fr)); margin-bottom: 30px; }
.foot h4 {
  font-family: var(--font-mono);
  font-size: 10.5px; letter-spacing: 0.14em; text-transform: uppercase;
  color: var(--muted); margin: 0 0 12px; font-weight: 500;
}
.foot ul { list-style: none; margin: 0; padding: 0; }
.foot li { margin-bottom: 8px; }
.foot a:hover { color: var(--accent); }
.foot__end {
  border-top: 1px solid var(--line);
  padding-top: 22px;
  display: flex; justify-content: space-between; gap: 14px; flex-wrap: wrap;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.03em;
}
.foot__right { display: inline-flex; align-items: center; gap: 12px; flex-wrap: wrap; }
.icp a { color: var(--muted); border-bottom: 1px dotted var(--line-strong); }
.icp a:hover { color: var(--accent); border-bottom-color: var(--accent); }

/* ---------- 404 ---------- */
.center { min-height: 62vh; display: grid; place-content: center; text-align: center; }

/* ---------- reveal on scroll ---------- */
.rv { opacity: 0; transform: translateY(14px); }
.rv.in { opacity: 1; transform: none; transition: opacity 0.6s ease, transform 0.6s cubic-bezier(0.2, 0.7, 0.3, 1); }

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { animation-duration: 0.001ms !important; transition-duration: 0.001ms !important; }
  .rv { opacity: 1; transform: none; }
}

/* ---------- responsive ---------- */
@media (max-width: 860px) {
  .nav { display: none; }
  .hero { padding-top: 60px; padding-bottom: 44px; }
  section { margin-bottom: 64px; }
  .statement { padding-left: 18px; }
}
@media (max-width: 560px) {
  body { font-size: 16px; }
  .brand__dom { display: none; }
  .classic { padding: 22px 20px; font-size: 1.06rem; line-height: 1.95; }
  .paper__bd, .card { padding: 20px 18px; }
  .foot__end { flex-direction: column; }
}

/* mobile nav strip (shown only when .nav is hidden) */
.subnav {
  display: none;
  border-bottom: 1px solid var(--line);
  background: var(--bg-soft);
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
}
.subnav__in { display: flex; gap: 4px; padding: 8px 24px; width: max-content; min-width: 100%; }
.subnav a {
  padding: 6px 12px; border-radius: var(--radius-sm);
  font-size: 13.5px; color: var(--fg-soft); white-space: nowrap;
}
.subnav a[aria-current="page"] { color: var(--accent); background: var(--panel-2); }
@media (max-width: 860px) { .subnav { display: block; } }

/* ---------- print ---------- */
@media print {
  body::before, body::after, .topbar, .subnav, .pager, .foot { display: none !important; }
  body { background: #fff; color: #000; }
  .card, .paper, .classic, .pull { break-inside: avoid; border-color: #ccc; }
  a { text-decoration: underline; }
}