/* =========================================================
   Transitioning from Pre-Training to Post-Training
   NeurIPS 2026 Workshop
   ========================================================= */

:root {
  --paper:      #ffffff;
  --paper-alt:  #ffffff;
  --ink:        #111111;
  --ink-soft:   #333333;
  --ink-faint:  #5a5a5a;
  --line:       #cfcfcf;
  --line-soft:  #dedede;
  --accent:     #1a3a70;   /* plain academic navy */
  --accent-dk:  #12274d;
  --accent-tint:#eef1f6;
  --white:      #ffffff;

  --maxw: 1080px;
  --maxw-narrow: 760px;

  --serif: "Times New Roman", Times, "Liberation Serif", Georgia, serif;
  --sans:  "Times New Roman", Times, "Liberation Serif", Georgia, serif;
  --mono:  "Courier New", Courier, monospace;

  --r: 3px;
}

/* ---------- Reset / base ---------- */
*, *::before, *::after { box-sizing: border-box; }

html { scroll-behavior: smooth; scroll-padding-top: 60px; }

body {
  margin: 0;
  font-family: var(--sans);
  font-size: 18px;
  line-height: 1.55;
  color: var(--ink);
  background: var(--paper);
}

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

h1, h2, h3 { font-family: var(--serif); font-weight: 700; line-height: 1.2; margin: 0; }
p { margin: 0 0 1.1em; }
a { color: var(--accent); text-decoration: underline; }
a:hover { color: var(--accent-dk); }
em { font-style: italic; }
strong { font-weight: 700; }

.wrap { max-width: var(--maxw); margin: 0 auto; padding: 0 24px; }
.wrap--narrow { max-width: var(--maxw-narrow); }

.skip-link {
  position: absolute; left: -999px; top: 0;
  background: var(--ink); color: var(--white);
  padding: 10px 16px; z-index: 200;
}
.skip-link:focus { left: 0; }

/* ---------- TBD placeholder marker ---------- */
.tbd {
  color: var(--accent-dk);
  font-style: italic;
}
.tbd::before { content: "["; }
.tbd::after { content: "]"; }

/* ---------- Header / nav ---------- */
.site-header {
  position: sticky; top: 0; z-index: 100;
  background: var(--paper);
  border-bottom: 2px solid var(--ink);
}
.nav {
  max-width: var(--maxw); margin: 0 auto; padding: 0 24px;
  height: 60px; display: flex; align-items: center; justify-content: space-between;
}
.nav__brand { display: inline-flex; align-items: center; gap: 8px; color: var(--ink); text-decoration: none; }
.nav__brand-text { font-family: var(--serif); font-weight: 700; font-size: 18px; }

.nav__menu {
  list-style: none; display: flex; gap: 24px; margin: 0; padding: 0;
}
.nav__menu a {
  color: var(--ink); font-size: 16px; font-weight: 400;
  padding: 6px 0; text-decoration: none;
}
.nav__menu a:hover { text-decoration: underline; }
.nav__menu a[aria-current] { font-weight: 700; text-decoration: underline; }

.nav__toggle {
  display: none; flex-direction: column; gap: 5px;
  background: none; border: 0; cursor: pointer; padding: 8px;
}
.nav__toggle span {
  width: 22px; height: 2px; background: var(--ink);
}
.nav__toggle[aria-expanded="true"] span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.nav__toggle[aria-expanded="true"] span:nth-child(2) { opacity: 0; }
.nav__toggle[aria-expanded="true"] span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* ---------- Hero ---------- */
.hero {
  padding: 56px 0 48px;
  background: var(--paper);
  border-bottom: 1px solid var(--line);
}
.hero__eyebrow {
  font-family: var(--sans); font-size: 14px;
  color: var(--ink-faint);
  margin: 0 0 14px;
}
.hero__title {
  font-size: clamp(2rem, 5vw, 3rem);
  margin: 0 0 20px;
}
.hero__lede {
  font-size: clamp(1rem, 2vw, 1.15rem);
  color: var(--ink-soft); margin: 0 0 28px;
}

.hero__facts {
  display: flex; flex-wrap: wrap; gap: 10px 40px; margin: 0 0 30px; padding: 14px 0;
  border-top: 1px solid var(--line); border-bottom: 1px solid var(--line);
}
.hero__facts div { margin: 0; }
.hero__facts dt {
  font-size: 13px; text-transform: uppercase;
  color: var(--ink-faint); font-weight: 700; margin: 0 0 3px;
}
.hero__facts dd { margin: 0; font-size: 16px; font-weight: 400; color: var(--ink); }

.hero__actions { display: flex; flex-wrap: wrap; gap: 14px; margin: 0 0 24px; }
.hero__meta { font-size: 14px; color: var(--ink-faint); margin: 0; }

/* ---------- Buttons ---------- */
.btn {
  display: inline-flex; align-items: center; justify-content: center;
  font-family: var(--sans); font-size: 16px; font-weight: 700;
  padding: 10px 20px; border-radius: var(--r); border: 1px solid var(--ink);
  cursor: pointer; text-decoration: none;
}
.btn:hover { text-decoration: underline; }
.btn--primary { background: var(--accent); color: var(--white); border-color: var(--accent); }
.btn--primary:hover { background: var(--accent-dk); border-color: var(--accent-dk); }
.btn--ghost { background: transparent; color: var(--ink); border-color: var(--ink); }
.btn--ghost:hover { background: var(--paper-alt); }

/* ---------- Inner page header ---------- */
.page-header {
  padding: 44px 0 36px;
  background: var(--paper);
  border-bottom: 1px solid var(--line);
}
.page-header__eyebrow {
  font-family: var(--sans); font-size: 14px;
  color: var(--ink-faint); margin: 0 0 10px;
}
.page-header__title { font-size: clamp(1.8rem, 4vw, 2.4rem); margin: 0; }
.page-header__intro { color: var(--ink-soft); margin: 14px 0 0; font-size: 1.05rem; }

.cta { margin-top: 30px; }

/* ---------- Sections ---------- */
.section { padding: 52px 0; border-bottom: 1px solid var(--line-soft); }
.section--alt { background: var(--paper-alt); }
.section__title {
  font-size: clamp(1.4rem, 3vw, 1.8rem);
  margin: 0 0 16px;
  padding-bottom: 10px;
  border-bottom: 2px solid var(--ink);
}
.section__intro { color: var(--ink-soft); max-width: 68ch; margin: 14px 0 26px; }

.subsection__title { font-size: 1.2rem; margin: 30px 0 12px; }

/* ---------- Overview ---------- */
.callout {
  background: var(--paper-alt);
  border: 1px solid var(--line);
  border-left: 3px solid var(--ink);
  padding: 20px 24px; margin: 28px 0;
}
.callout__title { font-size: 1.1rem; margin: 0 0 8px; }
.callout p { margin: 0; color: var(--ink-soft); }

.q-list { margin: 0; padding-left: 1.4em; list-style: decimal; }
.q-list li {
  padding: 0 0 12px 8px; margin: 0;
  color: var(--ink-soft);
}

/* ---------- Topic cards ---------- */
.cards {
  display: grid; grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 16px;
}
.card {
  background: var(--paper); border: 1px solid var(--line);
  padding: 20px 20px 18px;
}
.card__title { font-size: 1.1rem; margin: 0 0 8px; }
.card p { margin: 0; font-size: 15.5px; color: var(--ink-soft); }

/* ---------- Topics list ---------- */
.topics-list {
  list-style: none;
  max-width: 940px;
  margin: 4px 0 0;
  padding: 0;
}
.topics-list li {
  display: grid;
  grid-template-columns: 24px minmax(0, 1fr);
  gap: 10px;
  padding: 19px 14px 19px 8px;
}
.topics-list li::before {
  content: "\2022";
  color: var(--accent);
  font-size: 1.55rem;
  line-height: 1;
  transform: translateY(1px);
}
.topics-list__content h3 {
  margin: 0 0 5px;
  font-size: 1.08rem;
  color: var(--ink);
}
.topics-list__content p {
  margin: 0;
  color: var(--ink-soft);
  font-size: 16px;
  line-height: 1.55;
}

/* ---------- CFP facts ---------- */
.facts { list-style: none; margin: 20px 0; padding: 0; border-top: 1px solid var(--line); }
.facts li {
  display: flex; gap: 20px; padding: 12px 2px;
  border-bottom: 1px solid var(--line); flex-wrap: wrap;
}
.facts__k {
  flex: 0 0 170px; font-weight: 700; color: var(--ink);
  font-size: 15px;
}
.facts__v { flex: 1 1 260px; color: var(--ink-soft); }
.note {
  font-size: 15px; color: var(--ink-faint);
  background: var(--paper-alt); padding: 12px 16px;
  border: 1px solid var(--line);
}
.section--alt .note { background: var(--white); }

/* ---------- Timeline / dates ---------- */
.timeline { list-style: none; margin: 6px 0 0; padding: 0; }
.timeline__item {
  display: flex; align-items: baseline; gap: 20px;
  padding: 13px 0; border-bottom: 1px solid var(--line); flex-wrap: wrap;
}
.timeline__item:last-child { border-bottom: 0; }
.timeline__date {
  flex: 0 0 150px; font-family: var(--serif); font-size: 15px;
  font-weight: 700; color: var(--ink);
}
.timeline__label { flex: 1 1 auto; color: var(--ink-soft); }
.timeline__item.is-past { opacity: .55; }
.timeline__item.is-past .timeline__label { text-decoration: line-through; }

/* ---------- Schedule ---------- */
.schedule { width: 100%; border-collapse: collapse; margin-top: 6px; font-size: 16px; }
.schedule td { padding: 12px 14px; border-bottom: 1px solid var(--line); vertical-align: top; }
.schedule__time {
  font-family: var(--serif); font-size: 15px; font-weight: 700; color: var(--ink);
  white-space: nowrap; width: 140px;
}
.schedule__highlight { font-weight: 700; }
.muted { color: var(--ink-faint); font-size: .9em; }

/* ---------- People (speakers & organizers, clickable) ---------- */
.people {
  display: flex; flex-wrap: wrap; justify-content: center;
  gap: 26px;
}
.orgs {
  display: flex; flex-wrap: wrap; justify-content: center;
  gap: 22px;
}
.person {
  display: flex; flex-direction: column; align-items: center; text-align: center;
  gap: 4px; background: var(--paper); border: 1px solid var(--line);
  padding: 28px 22px 24px; color: var(--ink); text-decoration: none;
  width: 240px; box-sizing: border-box;
}
.orgs .person { width: 220px; padding: 24px 18px 22px; }
.person:hover { border-color: var(--ink); }
.person__name { font-family: var(--serif); font-weight: 700; font-size: 1.18rem; margin-top: 6px; }
.person__affil { font-size: 15px; color: var(--ink-soft); }
.person__ext { font-size: .72em; color: var(--ink-faint); vertical-align: super; }
.orgs .person__name { font-size: 1.08rem; }
.orgs .person__affil { font-size: 14px; color: var(--ink-faint); }

/* Avatar: <img> headshot, or initials fallback for a missing photo */
.avatar {
  width: 128px; height: 128px; border-radius: 50%;
  margin: 0 auto 14px; overflow: hidden;
  display: flex; align-items: center; justify-content: center;
  background: var(--paper-alt);
  border: 1px solid var(--line);
  font-family: var(--serif); font-weight: 700; font-size: 32px; color: var(--ink-soft);
}
img.avatar { object-fit: cover; display: block; }
.avatar[data-initials]::after { content: attr(data-initials); }
.avatar--sm { width: 92px; height: 92px; font-size: 24px; margin-bottom: 12px; }

/* ---------- Accepted papers empty state ---------- */
.empty-state {
  border: 1px dashed var(--line);
  padding: 40px 20px; text-align: center; background: var(--paper);
}
.section--alt .empty-state { background: var(--paper); }

/* ---------- Contact ---------- */
.contact p { font-size: 1.05rem; }

/* ---------- Footer ---------- */
.site-footer {
  background: var(--paper); color: var(--ink-soft); padding: 36px 0;
  border-top: 2px solid var(--ink);
}
.footer__inner { text-align: center; }
.footer__title { font-family: var(--serif); font-size: 1.1rem; color: var(--ink); margin: 0 0 6px; font-weight: 700; }
.footer__sub { font-size: 14px; margin: 0 0 4px; color: var(--ink-soft); }
.footer__credit { font-size: 13px; margin: 0; color: var(--ink-faint); }
.site-footer .tbd { color: var(--ink-faint); }

/* ---------- Responsive ---------- */
@media (max-width: 820px) {
  .nav__toggle { display: flex; }
  .nav__menu {
    position: absolute; top: 60px; left: 0; right: 0;
    flex-direction: column; gap: 0;
    background: var(--paper); border-bottom: 1px solid var(--line);
    padding: 8px 0;
    max-height: 0; overflow: hidden; transition: max-height .28s ease;
  }
  .nav__menu.is-open { max-height: 460px; }
  .nav__menu li { border-top: 1px solid var(--line-soft); }
  .nav__menu li:first-child { border-top: 0; }
  .nav__menu a { display: block; padding: 13px 24px; }
}

@media (max-width: 560px) {
  body { font-size: 17px; }
  .hero { padding: 44px 0 36px; }
  .section { padding: 40px 0; }
  .facts li, .timeline__item { gap: 6px 16px; }
  .facts__k { flex-basis: 100%; }
  .schedule__time { width: auto; }
}