/* AIIL shared styles: tokens, base, top bar, section labels, key/value rows, colophon.
   Used by index.html, collaborators.html and publications.html; page-specific rules stay inline. */

/* ========================================================================
   DESIGN TOKENS  —  paper + ink + cinnabar
   ======================================================================== */
:root {
  /* palette: paper + ink, tuned slightly cooler for the night-sky masthead */
  --night-sky:  #1f1f29;
  --brand-blue: #0081c0;
  --action-azure: #41a1cf;
  --paper:      #fefffc;          /* off-white canvas with a small paper warmth */
  --paper-deep: #f9faf7;          /* recessed paper panels */
  --paper-edge: #dee2de;          /* cool hairline rules */
  --ink:        #171717;          /* near-black */
  --ink-soft:   #444141;          /* body text second tier */
  --ink-faint:  #646464;          /* captions, meta */
  --surface:    #ffffff;
  --cinnabar:       #8d6a94;      /* primary ink (accent) */
  --cinnabar-soft:  #a58caa;      /* lighter wash */
  --cinnabar-deep:  #5e4466;      /* saturated stroke core */
  --ink-secondary:  #5e4466;      /* pairs with accent for two-ink flourishes */
  --shadow-soft: rgba(0, 0, 0, 0.08) 0 1px 1px 0, rgba(0, 0, 0, 0.08) 0 4px 5px 0;
  --shadow-nav: rgba(0, 0, 0, 0.12) 0 2px 10px 0;
  --shadow-hairline: rgb(222, 226, 222) 0 0 0 1px;

  /* type */
  --sans-zh: 'Noto Sans TC', system-ui, sans-serif;
  --serif-zh: 'Noto Serif TC', 'Iowan Old Style', 'Charter', Georgia, serif;
  --sans-en: 'Source Sans 3', 'Noto Sans TC', system-ui, sans-serif;
  --serif-en: 'Source Serif 4', 'Noto Serif TC', 'Iowan Old Style', 'Charter', Georgia, serif;
  --sans: var(--sans-zh);
  --serif: var(--serif-zh);
  --mono: 'JetBrains Mono', ui-monospace, 'SFMono-Regular', Menlo, monospace;

  /* rhythm */
  --measure: 62ch;
  --gutter: clamp(1rem, 4vw, 3rem);
}

/* ========================================================================
   RESET + BASE
   ======================================================================== */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; overflow-x: hidden; }
body {
  font-family: var(--sans);
  color: var(--ink);
  background: var(--paper);
  line-height: 1.55;
  font-size: 17px;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
  font-feature-settings: "ss01", "cv11", "calt";
  overflow-x: hidden;
}

/* paper texture — extremely subtle, two overlaid noise layers */
body::before {
  content: "";
  position: fixed; inset: 0;
  pointer-events: none;
  z-index: 0;
  opacity: 0.4;
  mix-blend-mode: multiply;
  background-image:
    radial-gradient(circle at 20% 30%, rgba(120,100,60,0.05) 0, transparent 40%),
    radial-gradient(circle at 80% 70%, rgba(80,60,40,0.05) 0, transparent 45%);
}
/* paper fibres - very faint crosshatch */
body::after {
  content: "";
  position: fixed; inset: 0;
  pointer-events: none;
  z-index: 0;
  opacity: 0.06;
  background-image:
    repeating-linear-gradient(45deg, rgba(27,26,23,0.5) 0 1px, transparent 1px 3px),
    repeating-linear-gradient(-45deg, rgba(27,26,23,0.3) 0 1px, transparent 1px 4px);
}

a { color: inherit; text-decoration: none; }
img { display: block; max-width: 100%; }
button { font: inherit; color: inherit; background: none; border: 0; cursor: pointer; }

::selection { background: var(--cinnabar); color: var(--paper); }

/* html[lang] gets appropriate type roles */
html[lang="zh-Hant"] { --sans: var(--sans-zh); --serif: var(--serif-zh); }
html[lang="en"] { --sans: var(--sans-en); --serif: var(--serif-en); }
html[lang="zh-Hant"] body { font-family: var(--serif); }
html[lang="en"] body { font-family: var(--sans); }

/* ========================================================================
   VERSION SWITCHER (top bar)
   ======================================================================== */
.shell {
  position: relative;
  z-index: 1;
}

.topbar {
  position: sticky;
  top: 0;
  z-index: 50;
  background: color-mix(in srgb, var(--paper) 78%, transparent);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid color-mix(in srgb, var(--paper-edge) 70%, transparent);
  box-shadow: 0 1px 12px rgba(0, 0, 0, 0.035);
}

.topbar-inner {
  max-width: 1400px;
  margin: 0 auto;
  padding: 14px var(--gutter);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  flex-wrap: wrap;
}

.seal {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  padding: 6px 12px 6px 8px;
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: 0.05em;
  color: var(--ink-soft);
  text-transform: uppercase;
  background: color-mix(in srgb, var(--paper) 76%, transparent);
  border: 1px solid color-mix(in srgb, var(--paper-edge) 70%, transparent);
  border-radius: 50px;
  box-shadow: rgba(0, 0, 0, 0.06) 0 1px 8px 0;
  backdrop-filter: blur(9px);
}
.seal-mark {
  width: 44px; height: 30px;
  display: inline-block;
  color: var(--cinnabar);
}
.seal-mark svg { width: 100%; height: 100%; display: block; overflow: visible; }

.version-switch {
  display: inline-flex;
  border: 1px solid color-mix(in srgb, var(--paper-edge) 72%, transparent);
  background: color-mix(in srgb, var(--paper-deep) 82%, transparent);
  padding: 4px;
  border-radius: 50px;
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.06em;
  box-shadow: rgba(0, 0, 0, 0.05) 0 1px 8px 0;
  backdrop-filter: blur(9px);
}
.version-switch a {
  padding: 7px 12px;
  color: var(--ink-faint);
  text-transform: uppercase;
  white-space: nowrap;
  border-radius: 50px;
  transition: color .15s, background .15s, box-shadow .15s;
}
.version-switch .active {
  background: var(--night-sky);
  color: var(--surface);
  box-shadow: rgba(0, 0, 0, 0.16) 0 2px 6px 0;
}
.version-switch a:hover:not(.active) { color: var(--ink); }

.topbar-right {
  display: inline-flex;
  align-items: center;
  gap: 1rem;
}

.lang-switch {
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.08em;
  color: var(--ink-faint);
  display: inline-flex;
  gap: 6px;
  align-items: center;
  padding: 6px 9px;
  border: 1px solid color-mix(in srgb, var(--paper-edge) 65%, transparent);
  border-radius: 50px;
  background: color-mix(in srgb, var(--paper) 76%, transparent);
  box-shadow: rgba(0, 0, 0, 0.045) 0 1px 8px 0;
  backdrop-filter: blur(9px);
}
.lang-switch button {
  color: var(--ink-faint);
  padding: 2px 4px;
  border-bottom: 1px solid transparent;
}
.lang-switch button.active {
  color: var(--night-sky);
  border-bottom-color: var(--brand-blue);
}
.lang-switch .sep { opacity: 0.4; }

/* ========================================================================
   SHARED PAGE PARTS
   ======================================================================== */
.v1 {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 var(--gutter) 6rem;
}

.v1-section-label {
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--ink-faint);
  padding-top: 0.4rem;
}
h2.v1-section-label { font-weight: 400; line-height: inherit; }
.v1-section-label::before {
  content: "§ ";
  color: var(--cinnabar);
}
/* hand-drawn underline beneath section labels */
.v1-section-label {
  position: relative;
  align-self: start;
  padding-bottom: 0.55rem;
}
.v1-section-label::after {
  content: "";
  position: absolute;
  left: 0; right: 20%;
  bottom: 0;
  height: 6px;
  background-image: var(--pen-underline, none);
  background-repeat: no-repeat;
  background-size: 100% 100%;
  opacity: calc(var(--ink-alpha, 0.75) * 0.85);
  pointer-events: none;
}

.v1-collab-lead {
  margin: 0;
  font-family: var(--serif);
  font-size: 1.1rem;
  line-height: 1.75;
  color: var(--ink);
}
html[lang="en"] .v1-collab-lead { font-family: var(--sans); }

.v1-contact-row {
  display: grid;
  grid-template-columns: 90px 1fr;
  padding: 0.8rem 0;
  border-top: 1px solid var(--paper-edge);
  gap: 1rem;
  align-items: baseline;
}
.v1-contact-row:last-child { border-bottom: 1px solid var(--paper-edge); }
.v1-contact-key {
  font-family: var(--mono);
  font-size: 10.5px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--ink-faint);
}

/* --- Colophon footer ----------------------------------------------- */
.v1-colophon {
  margin-top: 5rem;
  padding-top: 1.5rem;
  border-top: 1px solid var(--ink);
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  flex-wrap: wrap;
  gap: 1rem;
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.06em;
  color: var(--ink-faint);
}
.v1-colophon .seal-mark {
  width: 22px; height: 22px; font-size: 11px;
}



/* --- Sub-page frame (collaborators, publications) ------------------- */
.cp-head {
  padding: 4rem 0 2rem;
  border-bottom: 1px solid var(--paper-edge);
}
.cp-head h1 {
  font-family: var(--serif);
  font-size: clamp(1.8rem, 4vw, 2.6rem);
  font-weight: 600;
  line-height: 1.2;
  color: var(--ink);
}
html[lang="en"] .cp-head h1 { font-family: var(--sans); }
.cp-head .v1-collab-lead { margin-top: 0.9rem; }

.cp-group {
  padding: 3rem 0;
  border-bottom: 1px solid var(--paper-edge);
  display: grid;
  grid-template-columns: 200px minmax(0, 1fr);
  gap: 3rem;
}
.cp-group > div > :first-child { border-top: 0; }

.cp-cta {
  padding-top: 2.5rem;
  font-size: 1rem;
  color: var(--ink-soft);
}
.cp-cta a {
  font-family: var(--mono);
  color: var(--brand-blue);
  border-bottom: 1px solid color-mix(in srgb, var(--brand-blue) 72%, transparent);
}

@media (max-width: 900px) {
  .cp-group { grid-template-columns: 1fr; gap: 1.25rem; }
}

@media (max-width: 560px) {
  body { font-size: 16px; }
  .topbar-inner {
    padding: 10px var(--gutter);
    justify-content: center;
    gap: 0.55rem;
  }
  .seal {
    max-width: 100%;
    padding: 5px 10px 5px 7px;
    gap: 8px;
    font-size: 10.5px;
  }
  .seal-mark {
    width: 32px;
    height: 24px;
  }
  .topbar-right {
    gap: 0.5rem;
  }
  .lang-switch {
    padding: 5px 8px;
  }
  .version-switch {
    order: 2;
    max-width: 100%;
    overflow-x: auto;
    scrollbar-width: none;
  }
  .topbar-right {
    order: 3;
    width: 100%;
    justify-content: center;
  }
  .version-switch::-webkit-scrollbar { display: none; }
  .version-switch a { padding: 6px 8px; font-size: 10px; }
  .v1-contact-row {
    grid-template-columns: 1fr;
    gap: 0.25rem;
  }
}