/* ARRSI 2026 — hand-set in STIX Two Text & IBM Plex Mono */

/* ---------- fonts ---------- */
@font-face {
  font-family: "STIX Two Text";
  src: url("../fonts/stix-two-text-normal-400-700-latin.woff2") format("woff2");
  font-weight: 400 700;
  font-style: normal;
  font-display: swap;
}
@font-face {
  font-family: "STIX Two Text";
  src: url("../fonts/stix-two-text-italic-400-700-latin.woff2") format("woff2");
  font-weight: 400 700;
  font-style: italic;
  font-display: swap;
}
@font-face {
  font-family: "IBM Plex Mono";
  src: url("../fonts/ibm-plex-mono-normal-400-latin.woff2") format("woff2");
  font-weight: 400;
  font-style: normal;
  font-display: swap;
}
@font-face {
  font-family: "IBM Plex Mono";
  src: url("../fonts/ibm-plex-mono-normal-500-latin.woff2") format("woff2");
  font-weight: 500;
  font-style: normal;
  font-display: swap;
}

/* ---------- tokens ---------- */
:root {
  --paper: #fcfcfa;
  --paper-soft: #f4f4ef;
  --wash: #eef1fb;
  --ink: #16191d;
  --ink-soft: #50565e;
  --ink-faint: #878d95;
  --rule: #e2e1da;
  --accent: #2230b8;
  --accent-soft: #aab4ea;
  --serif: "STIX Two Text", "STIX Two Text Fallback", Georgia, "Times New Roman", serif;
  --mono: "IBM Plex Mono", ui-monospace, "SF Mono", Menlo, monospace;
  --measure: 66ch;
  color-scheme: light dark;
}
@media (prefers-color-scheme: dark) {
  :root {
    --paper: #111318;
    --paper-soft: #171a20;
    --wash: #171c2e;
    --ink: #e9e8e3;
    --ink-soft: #a8aeb7;
    --ink-faint: #757b84;
    --rule: #2a2e37;
    --accent: #93a0ff;
    --accent-soft: #3a468c;
  }
}

/* ---------- reset-ish ---------- */
* { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
html:focus-within { scroll-behavior: smooth; }
body {
  font-family: var(--serif);
  font-size: 1.0625rem;
  line-height: 1.62;
  background: var(--paper);
  color: var(--ink);
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}
img { max-width: 100%; display: block; }
a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; text-underline-offset: 3px; text-decoration-thickness: 1px; }
:focus-visible { outline: 2px solid var(--accent); outline-offset: 3px; border-radius: 1px; }

.skip-link {
  position: absolute; left: -999px; top: 0;
  background: var(--accent); color: var(--paper);
  padding: 0.5rem 1rem; z-index: 100; font-family: var(--mono); font-size: 0.8rem;
}
.skip-link:focus { left: 0; }

/* ---------- shared ---------- */
.container { max-width: 1120px; margin: 0 auto; padding: 0 clamp(1.25rem, 4vw, 2.5rem); }

.kicker {
  font-family: var(--mono);
  font-size: 0.72rem;
  font-weight: 500;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--ink-soft);
}
.kicker .sep { color: var(--accent); padding: 0 0.35em; }

/* ---------- masthead ---------- */
.masthead {
  position: sticky; top: 0; z-index: 50;
  background: color-mix(in srgb, var(--paper) 88%, transparent);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--rule);
}
.masthead-inner {
  display: flex; align-items: baseline; justify-content: space-between;
  gap: 1.5rem; padding-top: 0.8rem; padding-bottom: 0.8rem;
}
.wordmark {
  font-family: var(--serif); font-weight: 700; font-size: 1.05rem;
  letter-spacing: 0.01em; color: var(--ink); white-space: nowrap;
}
.wordmark:hover { text-decoration: none; color: var(--accent); }
.wordmark .year { color: var(--accent); font-weight: 400; font-style: italic; }
.masthead nav { display: flex; gap: clamp(0.9rem, 2.2vw, 1.6rem); flex-wrap: wrap; }
.masthead nav a {
  font-family: var(--mono); font-size: 0.72rem; font-weight: 500;
  letter-spacing: 0.12em; text-transform: uppercase; color: var(--ink-soft);
}
.masthead nav a:hover { color: var(--accent); text-decoration: none; }

/* ---------- hero ---------- */
.hero { padding: clamp(3rem, 7vw, 5.5rem) 0 clamp(2.5rem, 5vw, 4rem); }
.hero-grid {
  display: grid; grid-template-columns: minmax(0, 7fr) minmax(0, 4fr);
  gap: clamp(2rem, 5vw, 4.5rem); align-items: start;
}
.hero h1 {
  font-size: clamp(2.5rem, 5.6vw, 4.35rem);
  line-height: 1.04;
  font-weight: 600;
  letter-spacing: -0.015em;
  margin: 1.1rem 0 1.4rem;
  text-wrap: balance;
}
.hero h1 .amp { font-style: italic; font-weight: 400; color: var(--accent); }
.hero-venue {
  font-size: clamp(1.05rem, 1.6vw, 1.25rem);
  font-style: italic;
  color: var(--ink-soft);
  margin-bottom: 1.5rem;
}
.hero-venue strong { color: var(--ink); font-style: normal; font-weight: 600; }

.cta-row { display: flex; gap: 0.8rem; flex-wrap: wrap; margin-bottom: 2.4rem; }
.btn {
  display: inline-block;
  font-family: var(--mono); font-size: 0.73rem; font-weight: 500;
  letter-spacing: 0.11em; text-transform: uppercase;
  padding: 0.72rem 1.35rem; border: 1px solid var(--ink);
}
.btn:hover { text-decoration: none; }
.btn-solid { background: var(--ink); color: var(--paper); }
.btn-solid:hover { background: var(--accent); border-color: var(--accent); color: #fff; }
.btn-line { color: var(--ink); }
.btn-line:hover { border-color: var(--accent); color: var(--accent); }

.abstract { border-top: 2px solid var(--ink); padding-top: 1.1rem; max-width: var(--measure); }
.abstract h2 {
  font-family: var(--mono); font-size: 0.72rem; font-weight: 500;
  letter-spacing: 0.16em; text-transform: uppercase; color: var(--ink);
  margin-bottom: 0.7rem;
}
.abstract p { font-size: 0.98rem; line-height: 1.66; color: var(--ink-soft); hyphens: auto; }
.abstract p + p { margin-top: 0.75rem; }
.abstract p strong { color: var(--ink); font-weight: 600; }

/* hero right rail */
.hero-rail { display: flex; flex-direction: column; gap: 1.6rem; }

.figure { border: 1px solid var(--rule); background: var(--paper-soft); padding: 1.4rem 1.2rem 1rem; }
.figure svg { width: 100%; height: auto; display: block; }
.figure figcaption {
  margin-top: 0.9rem; padding-top: 0.7rem; border-top: 1px solid var(--rule);
  font-size: 0.82rem; line-height: 1.5; color: var(--ink-soft);
}
.figure figcaption .fig-label { font-family: var(--mono); font-size: 0.7rem; letter-spacing: 0.1em; text-transform: uppercase; color: var(--accent); }

.factlist { border-top: 2px solid var(--ink); }
.factlist div {
  display: flex; justify-content: space-between; gap: 1rem; align-items: baseline;
  padding: 0.55rem 0; border-bottom: 1px solid var(--rule);
}
.factlist dt { font-family: var(--mono); font-size: 0.68rem; font-weight: 500; letter-spacing: 0.13em; text-transform: uppercase; color: var(--ink-faint); }
.factlist dd { font-size: 0.92rem; text-align: right; }

/* figure drawing animation */
@media (prefers-reduced-motion: no-preference) {
  .loop-draw { stroke-dasharray: 1; stroke-dashoffset: 1; animation: draw 2s cubic-bezier(0.45, 0, 0.3, 1) forwards; }
  .loop-draw.d2 { animation-delay: 1.9s; animation-duration: 0.55s; animation-timing-function: cubic-bezier(0.2, 0.6, 0.4, 1); }
  .loop-node { opacity: 0; animation: appear 0.5s ease forwards; }
  .loop-node.n1 { animation-delay: 0.2s; } .loop-node.n2 { animation-delay: 1.3s; }
  .loop-node.n3 { animation-delay: 1.45s; } .loop-node.n4 { animation-delay: 1.6s; }
  .loop-node.n5 { animation-delay: 1.75s; } .loop-node.n6 { animation-delay: 1.9s; }
  .loop-node.n7 { animation-delay: 2.35s; }
  .hero-grid > * { opacity: 0; transform: translateY(10px); animation: rise 0.7s cubic-bezier(0.2, 0.7, 0.3, 1) forwards; }
  .hero-grid > *:nth-child(2) { animation-delay: 0.15s; }
}
@keyframes draw { to { stroke-dashoffset: 0; } }
@keyframes appear { to { opacity: 1; } }
@keyframes rise { to { opacity: 1; transform: none; } }

/* svg figure strokes */
.fig-ink { stroke: var(--ink); }
.fig-ink-fill { fill: var(--ink); }
.fig-accent { stroke: var(--accent); }
.fig-accent-fill { fill: var(--accent); }
.fig-paper-fill { fill: var(--paper-soft); }
.fig-label-text { font-family: var(--mono); font-size: 10.5px; letter-spacing: 0.04em; fill: var(--ink); }
.fig-label-accent { font-family: var(--mono); font-size: 10px; letter-spacing: 0.03em; fill: var(--accent); font-style: italic; }

/* ---------- sections ---------- */
section.block { padding: clamp(2.6rem, 5.5vw, 4.2rem) 0 0; }
section.block:last-of-type { padding-bottom: clamp(2.6rem, 5.5vw, 4rem); }
.block-head {
  display: flex; align-items: baseline; gap: 1.1rem;
  border-top: 2px solid var(--ink); padding-top: 1rem; margin-bottom: 1.7rem;
}
.block-head .no {
  font-family: var(--mono); font-size: 0.85rem; font-weight: 500; color: var(--accent);
}
.block-head h2 { font-size: clamp(1.45rem, 2.6vw, 1.9rem); font-weight: 600; letter-spacing: -0.01em; }
.block-head .aside-note { margin-left: auto; font-family: var(--mono); font-size: 0.68rem; letter-spacing: 0.12em; text-transform: uppercase; color: var(--ink-faint); }

.prose { max-width: var(--measure); }
.prose p + p { margin-top: 0.9rem; }
.prose .lede { font-size: 1.15rem; line-height: 1.6; }
.prose em { color: var(--ink); }

/* two-column section layout: side note + content */
.split { display: grid; grid-template-columns: minmax(0, 7fr) minmax(0, 4fr); gap: clamp(2rem, 5vw, 4.5rem); align-items: start; }

.sidenote { font-size: 0.92rem; color: var(--ink-soft); border-left: 2px solid var(--accent); padding-left: 1rem; }
.sidenote strong { color: var(--ink); }

/* ---------- topics ---------- */
.topics { display: grid; grid-template-columns: 1fr 1fr; gap: 0; border-top: 1px solid var(--rule); margin-top: 0.5rem; }
.topic { padding: 1.05rem 1.4rem 1.05rem 0; border-bottom: 1px solid var(--rule); }
.topic:nth-child(odd) { padding-right: 2.2rem; }
.topic:nth-child(even) { padding-left: 2.2rem; border-left: 1px solid var(--rule); }
.topic h3 { font-size: 1.04rem; font-weight: 600; margin-bottom: 0.2rem; }
.topic h3 .t-no { font-family: var(--mono); font-size: 0.68rem; font-weight: 500; color: var(--accent); margin-right: 0.55em; vertical-align: 0.12em; }
.topic p { font-size: 0.9rem; color: var(--ink-soft); line-height: 1.55; }

/* ---------- booktabs tables ---------- */
.tabular { width: 100%; border-collapse: collapse; border-top: 2px solid var(--ink); border-bottom: 2px solid var(--ink); }
.tabular caption {
  caption-side: bottom; text-align: left; padding-top: 0.65rem;
  font-size: 0.82rem; color: var(--ink-faint); font-style: italic;
}
.tabular th {
  font-family: var(--mono); font-size: 0.68rem; font-weight: 500;
  letter-spacing: 0.13em; text-transform: uppercase; color: var(--ink-faint);
  text-align: left; padding: 0.6rem 1rem 0.6rem 0; border-bottom: 1px solid var(--ink);
}
.tabular td { padding: 0.68rem 1rem 0.68rem 0; border-bottom: 1px solid var(--rule); vertical-align: baseline; }
.tabular tr:last-child td { border-bottom: none; }
.tabular .mono { font-family: var(--mono); font-size: 0.82rem; }
.tabular .tba { color: var(--ink-faint); font-style: italic; }
.tabular .hl td { background: var(--wash); }
.tabular .hl td:first-child { box-shadow: inset 2px 0 0 var(--accent); padding-left: 0.75rem; }

/* ---------- speakers ---------- */
.tba-panel {
  border: 1px dashed var(--accent-soft); background: var(--wash);
  padding: clamp(1.8rem, 4vw, 2.8rem); text-align: center;
}
.tba-panel .big { font-size: clamp(1.2rem, 2.4vw, 1.55rem); font-style: italic; }
.tba-panel p { max-width: 46ch; margin: 0.6rem auto 0; font-size: 0.92rem; color: var(--ink-soft); }

/* ---------- people ---------- */
.people { display: grid; grid-template-columns: repeat(5, 1fr); gap: 1.6rem 1.4rem; }
.people.compact { grid-template-columns: repeat(5, 1fr); }
.person { display: block; color: inherit; }
.person:hover { text-decoration: none; }
.person .photo {
  display: block;
  aspect-ratio: 1 / 1; overflow: hidden; background: var(--paper-soft);
  border: 1px solid var(--rule); margin-bottom: 0.65rem; position: relative;
}
.person img {
  width: 100%; height: 100%; object-fit: cover;
  transition: transform 0.35s ease;
}
.person:hover img { transform: scale(1.025); }
.person h3 { font-size: 1rem; font-weight: 600; line-height: 1.3; }
.person:hover h3 { color: var(--accent); }
.person h3 .ext { font-family: var(--mono); font-size: 0.7rem; color: var(--accent); opacity: 0; transition: opacity 0.2s ease; margin-left: 0.3em; }
.person:hover h3 .ext { opacity: 1; }
.person .aff { font-size: 0.82rem; line-height: 1.42; color: var(--ink-soft); margin-top: 0.15rem; }
span.person { cursor: default; }

.people-note { margin-top: 1.4rem; font-size: 0.88rem; color: var(--ink-faint); font-style: italic; max-width: var(--measure); }

/* ---------- submit ---------- */
.submit-actions { display: flex; flex-direction: column; gap: 0.8rem; align-items: stretch; max-width: 260px; }
.submit-actions .btn { text-align: center; }

/* ---------- footer ---------- */
footer { margin-top: clamp(3rem, 6vw, 5rem); border-top: 2px solid var(--ink); background: var(--paper-soft); }
.footer-grid {
  display: grid; grid-template-columns: repeat(3, 1fr); gap: 2.5rem;
  padding: clamp(2rem, 4vw, 3rem) 0;
}
.footer-grid h2 {
  font-family: var(--mono); font-size: 0.7rem; font-weight: 500;
  letter-spacing: 0.15em; text-transform: uppercase; color: var(--ink-faint);
  margin-bottom: 0.8rem;
}
.footer-grid p, .footer-grid li { font-size: 0.92rem; color: var(--ink-soft); line-height: 1.6; }
.email-ob { font-family: var(--mono); font-size: 0.8rem; color: var(--accent); }
.footer-grid ul { list-style: none; }
.footer-grid li + li { margin-top: 0.35rem; }
.colophon {
  border-top: 1px solid var(--rule); padding: 1.1rem 0 1.4rem;
  display: flex; justify-content: space-between; gap: 1rem; flex-wrap: wrap;
  font-family: var(--mono); font-size: 0.68rem; letter-spacing: 0.08em;
  color: var(--ink-faint);
}

/* ---------- responsive ---------- */
@media (max-width: 980px) {
  .hero-grid, .split { grid-template-columns: 1fr; }
  .hero-rail { flex-direction: row; align-items: start; }
  .hero-rail > * { flex: 1 1 0; }
  .people, .people.compact { grid-template-columns: repeat(3, 1fr); }
}
@media (max-width: 720px) {
  .hero-rail { flex-direction: column; }
  .hero-rail > * { width: 100%; }
  .topics { grid-template-columns: 1fr; }
  .topic:nth-child(odd) { padding-right: 0; }
  .topic:nth-child(even) { padding-left: 0; border-left: none; }
  .people, .people.compact { grid-template-columns: repeat(2, 1fr); }
  .masthead nav { gap: 0.8rem; }
  .masthead nav a:nth-child(n+5) { display: none; }
  .footer-grid { grid-template-columns: 1fr; gap: 1.8rem; }
  .block-head .aside-note { display: none; }
}
@media (max-width: 420px) {
  .people, .people.compact { grid-template-columns: repeat(2, 1fr); gap: 1.1rem 0.9rem; }
  .person h3 { font-size: 0.92rem; }
  .person .aff { font-size: 0.76rem; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { animation: none !important; transition: none !important; }
}