/* ----------------------------------------------------------------
   SemanticQA blog — design tokens (Anthropic-flavored type system)
   palette: sky blue · white · interleaved bands
---------------------------------------------------------------- */
:root {
  --paper:       #ffffff;
  --paper-2:     #eef5ff;
  --surface:     #ffffff;
  --band:        #f5f9ff;
  --ink:         #0f1a2e;
  --ink-2:       #2a3a55;
  --muted:       #5a6b85;
  --muted-2:     #93a1bb;
  --rule:        #d6e4f7;
  --rule-soft:   #e7eefb;
  --accent:      #80b1ef;
  --accent-2:    #5c95df;
  --accent-3:    #a8c8f5;
  --accent-ink:  #1f4a87;
  --accent-soft: #e1ecfb;
  --accent-glow: rgba(128, 177, 239, .35);
  --gold:        #80b1ef;
  --gold-soft:   #d8e6fa;
  --code-bg:     #eef5ff;
  --shadow-sm:   0 1px 2px rgba(20, 40, 80, .04), 0 1px 1px rgba(20, 40, 80, .03);
  --shadow-md:   0 8px 24px rgba(30, 60, 110, .06), 0 2px 6px rgba(30, 60, 110, .04);
  --shadow-lg:   0 24px 60px rgba(30, 60, 110, .10), 0 6px 18px rgba(30, 60, 110, .06);

  /* Anthropic-flavored type system. anthropicSerif = display + body serif,
     anthropicSans = UI sans, anthropicMono = code. Aliases kept for back-compat. */
  --anthropicSerif: "Fraunces", "Source Serif 4", "Iowan Old Style", Georgia, "Times New Roman", serif;
  --anthropicSans:  "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", system-ui, sans-serif;
  --anthropicMono:  "JetBrains Mono", "SF Mono", "Menlo", Consolas, monospace;
  --serif:  var(--anthropicSerif);
  --sans:   var(--anthropicSans);
  --mono:   var(--anthropicMono);

  --maxw:        1080px;
  --maxw-prose:  760px;
  --radius:      10px;
  --radius-lg:   16px;
  --ease-out:    cubic-bezier(.22, 1, .36, 1);
  --ease-spring: cubic-bezier(.34, 1.56, .64, 1);
}

@media (prefers-color-scheme: dark) {
  :root {
    --paper:     #0e1626;
    --paper-2:   #131d33;
    --surface:   #16223b;
    --band:      #111a2d;
    --ink:       #eaf0fb;
    --ink-2:     #c7d2e7;
    --muted:     #91a0bf;
    --muted-2:   #6b7796;
    --rule:      #25324c;
    --rule-soft: #1c283f;
    --accent:    #80b1ef;
    --accent-2:  #a8c8f5;
    --accent-3:  #5c95df;
    --accent-ink:#cfe0f9;
    --accent-soft:#1d2c4a;
    --accent-glow: rgba(128, 177, 239, .25);
    --gold:      #80b1ef;
    --gold-soft: #243a5b;
    --code-bg:   #1a2640;
  }
}

/* ----- reset & base ------------------------------------------------ */
*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }
body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--anthropicSerif);
  font-size: 17.5px;
  line-height: 1.7;
  font-feature-settings: "kern", "liga", "onum", "ss01";
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  font-optical-sizing: auto;
}
img, svg { max-width: 100%; height: auto; display: block; }
a {
  color: var(--accent-ink);
  text-decoration: none;
  background-image: linear-gradient(currentColor, currentColor);
  background-size: 0% 1px;
  background-repeat: no-repeat;
  background-position: 0 100%;
  transition: background-size .35s var(--ease-out), color .15s ease;
}
hr { border: 0; border-top: 1px solid var(--rule); margin: 4rem 0; }
h1, h2, h3, h4 {
  font-family: var(--anthropicSerif);
  color: var(--ink);
  letter-spacing: -.012em;
  line-height: 1.2;
  font-weight: 600;
  font-optical-sizing: auto;
}
h1 { font-size: clamp(2.3rem, 4.8vw, 3.6rem); margin: 0 0 1.25rem; letter-spacing: -.024em; font-weight: 500; }
h2 { font-size: clamp(1.65rem, 2.6vw, 2.1rem); margin: 4rem 0 1.2rem; }
h3 { font-size: 1.22rem; margin: 2.4rem 0 .7rem; }
h4 { font-size: 1.04rem; margin: 1.6rem 0 .5rem; color: var(--ink-2); }
p  { margin: 0 0 1.15rem; color: var(--ink-2); }
strong { color: var(--ink); font-weight: 600; }
em { color: var(--ink-2); }
small { color: var(--muted); }
code, pre, kbd, samp { font-family: var(--anthropicMono); }
code {
  font-size: .88em;
  background: var(--code-bg);
  padding: .12em .4em;
  border-radius: 5px;
  color: var(--accent-ink);
}
pre {
  background: var(--code-bg);
  border: 1px solid var(--rule);
  border-radius: var(--radius);
  padding: 1.2rem 1.3rem;
  overflow-x: auto;
  font-size: .85rem;
  line-height: 1.6;
  color: var(--ink);
}
pre code { background: transparent; padding: 0; color: inherit; }
blockquote {
  margin: 1.8rem 0;
  padding: .35rem 0 .35rem 1.3rem;
  border-left: 3px solid var(--accent);
  color: var(--ink-2);
  font-style: italic;
}
ul, ol { padding-left: 1.4rem; color: var(--ink-2); }
li { margin: .35rem 0; }
li::marker { color: var(--accent); }
::selection { background: #1f4a87; color: #ffffff; text-shadow: none; }
::-moz-selection { background: #1f4a87; color: #ffffff; text-shadow: none; }
a::selection { background: #1f4a87; color: #ffffff; background-image: none; }
a::-moz-selection { background: #1f4a87; color: #ffffff; background-image: none; }
.nav a::selection,
.nav a *::selection { background: #1f4a87; color: #ffffff; text-decoration: none; background-image: none; }
.nav a::-moz-selection,
.nav a *::-moz-selection { background: #1f4a87; color: #ffffff; text-decoration: none; background-image: none; }
.nav a:has(::selection)::after,
.nav a.active:has(::selection)::after { background: transparent; }

/* ----- layout primitives ----------------------------------------- */
.container { max-width: var(--maxw); margin: 0 auto; padding: 0 3rem; }
.prose     { max-width: var(--maxw); margin: 0 auto; padding: 0 3rem; }
.prose > p, .prose > blockquote, .prose > .pull,
.prose > ul, .prose > ol { max-width: var(--maxw-prose); }
section    { padding: 5.5rem 0; }
section + section { padding-top: 5.5rem; }
section.band:has(#tasks-overview) { padding-top: 3rem; padding-bottom: 3rem; }
section.container#taxonomy { padding-bottom: 7.5rem; }
section.section-tall { padding-top: 9rem; padding-bottom: 7rem; }
section#cite { padding-top: 4.5rem; padding-bottom: 2rem; }
section#cite .section-head { margin-bottom: 1.4rem; padding-bottom: .8rem; }
section#cite + .site-footer,
section#cite ~ .site-footer { margin-top: 1.5rem; }
.band      { background: var(--band); position: relative; }
.band-edge { border-top: 1px solid var(--rule-soft); border-bottom: 1px solid var(--rule-soft); }

@media (max-width: 900px) {
  .container, .prose { padding: 0 2.5rem; }
}
@media (max-width: 640px) {
  .container, .prose { padding: 0 2rem; }
  section { padding: 3.5rem 0; }
}
@media (max-width: 420px) {
  .container, .prose { padding: 0 1.5rem; }
}

.eyebrow {
  font-family: var(--anthropicSans);
  font-size: .72rem;
  font-weight: 600;
  letter-spacing: .14em;
  text-transform: uppercase;
  color: var(--accent-ink);
  margin: 0 0 1rem;
  display: inline-block;
  padding: .25rem .65rem;
  border: 1px solid var(--rule);
  border-radius: 999px;
  background: var(--accent-soft);
}
.lede {
  font-size: 1.2rem;
  line-height: 1.6;
  color: var(--ink-2);
  max-width: 64ch;
  margin-bottom: 1.8rem;
}
.muted { color: var(--muted); }

/* ----- reveal-on-scroll animation -------------------------------- */
.reveal {
  opacity: 0;
  transform: translateY(18px);
  transition: opacity .7s var(--ease-out), transform .7s var(--ease-out);
  will-change: opacity, transform;
}
.reveal.visible { opacity: 1; transform: none; }
.reveal-stagger > * {
  opacity: 0;
  transform: translateY(14px);
  transition: opacity .55s var(--ease-out), transform .55s var(--ease-out);
}
.reveal-stagger.visible > * { opacity: 1; transform: none; }
.reveal-stagger.visible > *:nth-child(1) { transition-delay: .04s; }
.reveal-stagger.visible > *:nth-child(2) { transition-delay: .12s; }
.reveal-stagger.visible > *:nth-child(3) { transition-delay: .20s; }
.reveal-stagger.visible > *:nth-child(4) { transition-delay: .28s; }
.reveal-stagger.visible > *:nth-child(5) { transition-delay: .36s; }
.reveal-stagger.visible > *:nth-child(6) { transition-delay: .44s; }

/* ----- header / nav ---------------------------------------------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: color-mix(in srgb, var(--paper) 80%, transparent);
  backdrop-filter: saturate(160%) blur(14px);
  -webkit-backdrop-filter: saturate(160%) blur(14px);
  border-bottom: 1px solid var(--rule);
  transition: background .25s var(--ease-out), border-color .25s var(--ease-out);
}
.site-header.scrolled { background: color-mix(in srgb, var(--paper) 92%, transparent); box-shadow: 0 2px 14px rgba(30, 60, 110, .05); }
.site-header .bar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 72px;
  position: relative;
}
.brand {
  font-family: var(--anthropicSerif);
  font-weight: 600;
  font-size: 1.1rem;
  letter-spacing: -.01em;
  color: var(--ink);
  background-image: none;
  display: inline-flex;
  align-items: center;
  gap: .65rem;
}
.brand-logo {
  height: 32px;
  width: auto;
  display: block;
  flex: 0 0 auto;
}
@media (max-width: 640px) {
  .brand-logo { height: 26px; }
}
.brand .mark {
  display: inline-block;
  width: .5rem;
  height: .5rem;
  background: var(--accent);
  border-radius: 50%;
  transform: translateY(-3px);
  box-shadow: 0 0 0 2.5px var(--accent-soft);
  animation: brand-pulse 3.5s var(--ease-out) infinite;
}
@keyframes brand-pulse {
  0%, 100% { box-shadow: 0 0 0 2.5px var(--accent-soft); }
  50%      { box-shadow: 0 0 0 4.5px var(--accent-soft); }
}
.brand em { font-style: italic; color: var(--muted); font-weight: 400; }
.nav { display: flex; gap: 2rem; font-family: var(--anthropicSerif); font-size: .98rem; font-weight: 700; }
.nav a {
  color: var(--ink-2);
  background-image: none;
  position: relative;
  padding: .15rem 0;
  font-weight: 700;
  transition: color .2s var(--ease-out);
}
.nav a::after { display: none; content: none; }
.nav a.active { color: var(--accent-2); }
.nav a.active::after { display: none; content: none; }

/* hamburger (hidden on desktop) */
.nav-toggle {
  display: none;
  width: 22px;
  height: 22px;
  padding: 0;
  background: transparent;
  border: 1px solid var(--rule);
  border-radius: 4px;
  cursor: pointer;
  position: relative;
  transition: border-color .2s, background .2s;
}
.nav-toggle span {
  position: absolute;
  left: 5px; right: 5px;
  height: 1.25px;
  background: var(--ink-2);
  border-radius: 2px;
  transition: transform .25s var(--ease-out), opacity .2s, top .25s var(--ease-out);
}
.nav-toggle span:nth-child(1) { top: 6px; }
.nav-toggle span:nth-child(2) { top: 10px; }
.nav-toggle span:nth-child(3) { top: 14px; }
.nav-toggle[aria-expanded="true"] span:nth-child(1) { top: 10px; transform: rotate(45deg); }
.nav-toggle[aria-expanded="true"] span:nth-child(2) { opacity: 0; }
.nav-toggle[aria-expanded="true"] span:nth-child(3) { top: 10px; transform: rotate(-45deg); }

@media (max-width: 760px) {
  .nav-toggle { display: block; }
  .nav {
    position: absolute;
    top: 100%; left: 0; right: 0;
    flex-direction: column;
    gap: 0;
    padding: .5rem 1.25rem 1rem;
    background: var(--paper);
    border-bottom: 1px solid var(--rule);
    box-shadow: var(--shadow-md);
    transform: translateY(-8px);
    opacity: 0;
    pointer-events: none;
    visibility: hidden;
    transition: opacity .25s var(--ease-out), transform .25s var(--ease-out), visibility .25s;
  }
  .nav.open {
    opacity: 1;
    transform: none;
    pointer-events: auto;
    visibility: visible;
  }
  .nav a {
    padding: .85rem 0;
    border-bottom: 1px solid var(--rule-soft);
  }
  .nav a:last-child { border-bottom: 0; }
  .nav a::after { display: none; }
  .nav a.active { color: var(--accent-ink); padding-left: .75rem; border-left: 2px solid var(--accent); }
  .site-header .bar { height: 60px; }
}

/* ----- hero ------------------------------------------------------ */
.hero-banner {
  width: calc(100% - 2.5rem);
  max-width: calc(var(--maxw) - 40px);
  margin: 1.25rem auto 0;
  height: 180px;
  background-image: url("../img/san_diego.jpg");
  background-size: cover;
  background-position: center 55%;
  background-repeat: no-repeat;
  border-radius: var(--radius-lg);
  box-shadow:
    0 22px 48px rgba(20, 40, 80, .22),
    0 10px 22px rgba(20, 40, 80, .14),
    0 3px 8px rgba(20, 40, 80, .10);
}
@media (max-width: 900px) { .hero-banner { height: 150px; border-radius: var(--radius); } }
@media (max-width: 640px) { .hero-banner { height: 120px; margin-top: .75rem; } }

.hero {
  padding: 1.85rem 4.5rem 3.5rem;
  position: relative;
  overflow: hidden;
  isolation: isolate;
}
@media (max-width: 900px) { .hero { padding: 1.4rem 2.25rem 3rem; } }
@media (max-width: 640px) { .hero { padding: 1.05rem 1.25rem 2.5rem; } }

/* iPhone 13 Pro → 17 Pro: keep "a Pain in the Neck" on one line */
@media (min-width: 390px) and (max-width: 430px) {
  .hero h1 { max-width: none; font-size: 1.85rem; line-height: 1.18; }
  .hero h1 .pain { white-space: nowrap; }
}
.hero::before, .hero::after { display: none; }
.hero .meta {
  font-family: var(--anthropicSans);
  font-size: .82rem;
  color: var(--muted);
  letter-spacing: .04em;
  margin-bottom: .6rem;
}
.hero .meta .dot { margin: 0 .55rem; color: var(--rule); }

/* ACL acceptance — simple bordered box */
.acl-note {
  display: inline-block;
  margin-bottom: 1.1rem;
  padding: .35rem .8rem;
  font-family: var(--anthropicSans);
  font-size: .82rem;
  font-weight: 500;
  color: var(--accent-ink);
  border: 1px solid var(--accent);
  border-radius: 6px;
  background: transparent;
  background-image: none;
  transition: none;
}
.acl-note.nav-acl {
  margin: 0 0 0 .85rem;
  padding: .25rem .65rem;
  font-size: .78rem;
  line-height: 1.3;
  white-space: nowrap;
  align-self: center;
}
.brand-wrap {
  display: inline-flex;
  align-items: center;
  gap: .55rem;
  margin-left: -1.75rem;
}
@media (max-width: 900px) { .brand-wrap { margin-left: -1.5rem; } }
@media (max-width: 640px) { .brand-wrap { margin-left: -1.25rem; } }
.brand-sep {
  font-family: var(--anthropicSerif);
  font-size: 1.1rem;
  color: var(--muted);
  font-weight: 400;
}
.brand-acl {
  font-family: var(--anthropicSerif);
  font-weight: 600;
  font-size: 1.1rem;
  letter-spacing: -.01em;
  color: var(--ink);
  white-space: nowrap;
}
.site-header .bar > .brand { margin-right: .25rem; }
@media (max-width: 640px) {
  .acl-note.nav-acl { display: none; }
  .brand-sep, .brand-acl { display: none; }
}
.hero h1 .pain {
  font-style: italic;
  color: var(--accent-ink);
  background: linear-gradient(120deg, var(--accent-ink), var(--accent-2));
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}
.hero h1 .colon {
  font-style: italic;
  color: var(--accent-ink);
  font-weight: 500;
}
.authors { font-family: var(--anthropicSans); font-size: 1rem; color: var(--ink-2); margin-top: .6rem; }
.authors .author-mute { color: var(--muted-2); }
.authors .author-mute sup { color: var(--muted-2); }
.authors .author-shame,
.authors .author-mute .author-shame {
  color: color-mix(in srgb, var(--muted-2) 55%, transparent);
  opacity: .7;
  font-weight: 400;
  letter-spacing: -.005em;
  text-decoration: line-through;
  text-decoration-color: color-mix(in srgb, var(--muted-2) 50%, transparent);
  text-decoration-thickness: 1px;
}
.authors .author-shame sup { color: color-mix(in srgb, var(--muted-2) 55%, transparent); }
.affil   { font-family: var(--anthropicSans); font-size: .88rem; color: var(--muted); margin-top: .5rem; }
.actions { display: flex; flex-wrap: wrap; gap: .8rem; margin-top: 2.4rem; }

.btn {
  display: inline-flex;
  align-items: center;
  gap: .55rem;
  padding: .72rem 1.25rem;
  font-family: var(--anthropicSans);
  font-size: .92rem;
  font-weight: 500;
  border-radius: var(--radius);
  border: 1px solid var(--rule);
  background: var(--surface);
  color: var(--ink);
  background-image: none;
  transition: border-color .2s, color .2s, background .2s;
}
.btn-primary { background: var(--accent); border-color: var(--accent); color: #ffffff; }
.btn .ico { width: 14px; height: 14px; }

/* ----- abstract / pull blocks ----------------------------------- */
.pull {
  border-left: 3px solid var(--accent);
  padding: .25rem 0 .25rem 1.6rem;
  margin: 1.8rem 0 2.4rem;
  font-size: 1.12rem;
  color: var(--ink-2);
  max-width: 66ch;
}
.callout {
  background: var(--accent-soft);
  border: 1px solid var(--rule);
  border-left: 3px solid var(--accent);
  border-radius: var(--radius);
  padding: 1.3rem 1.5rem;
  margin: 2rem 0;
  font-size: .98rem;
  color: var(--ink-2);
  position: relative;
  overflow: hidden;
}
.callout::before {
  content: "";
  position: absolute;
  top: -40%; right: -10%;
  width: 220px; height: 220px;
  background: radial-gradient(circle, color-mix(in srgb, var(--accent) 30%, transparent) 0%, transparent 70%);
  opacity: .55;
  pointer-events: none;
}
.callout strong { color: var(--ink); }

/* ----- card grids ------------------------------------------------ */
.grid { display: grid; gap: 1.75rem; }
.grid-2 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.grid-3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }
.grid-4 { grid-template-columns: repeat(4, minmax(0, 1fr)); }
@media (max-width: 880px) {
  .grid-3, .grid-4 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}
@media (max-width: 540px) {
  .grid-2, .grid-3, .grid-4 { grid-template-columns: 1fr; }
}
.card {
  background: var(--surface);
  border: 1px solid var(--rule);
  border-radius: var(--radius-lg);
  padding: 1.7rem 1.85rem;
  transition: border-color .25s, box-shadow .25s var(--ease-out);
}
.card h3 { margin: .65rem 0 .55rem; font-size: 1.1rem; }
.card p  { margin: 0; font-size: .96rem; color: var(--muted); line-height: 1.65; }
.card .badge {
  font-family: var(--anthropicSans);
  font-size: .7rem;
  letter-spacing: .1em;
  text-transform: uppercase;
  color: var(--accent-ink);
  font-weight: 600;
  display: inline-block;
  padding: .3em .75em;
  background: var(--accent-soft);
  border-radius: 999px;
  border: 1px solid color-mix(in srgb, var(--accent) 25%, transparent);
}
.card .stat {
  font-family: var(--anthropicSerif);
  font-size: 2.3rem;
  font-weight: 600;
  letter-spacing: -.02em;
  color: var(--ink);
  line-height: 1;
}
.card .stat .unit { font-size: .9rem; color: var(--muted); margin-left: .25rem; }

/* ----- global motion kill-switch (perf) -------------------------- */
*, *::before, *::after {
  animation: none !important;
  transition: none !important;
}
html { scroll-behavior: auto; }
.reveal, .reveal-stagger > * { opacity: 1 !important; transform: none !important; }