/* ── RESET ──────────────────────────────────────────────────── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
img { display: block; max-width: 100%; }

/* ── TOKENS ─────────────────────────────────────────────────── */
:root {
  --white:  #ffffff;
  --text:   #cccccc;
  --dim:    #888888;
  --xdim:   #555555;
  --rule:   #222222;
  --bg:     #000000;
  --font: 'Helvetica Neue', Helvetica, Arial, sans-serif;
}

/* ── BASE ───────────────────────────────────────────────────── */
body {
  font-family: var(--font);
  font-size: 15px;
  line-height: 1.75;
  letter-spacing: 0.035em;
  color: var(--text);
  background: var(--bg);
  -webkit-font-smoothing: antialiased;
}
a { color: var(--text); text-decoration: none; }
a:hover { color: var(--white); }
em { font-style: italic; }
strong { font-weight: 500; color: var(--white); }

/* ── HEADER ─────────────────────────────────────────────────── */
header {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  padding: 2rem 2.5rem 1.6rem;
  border-bottom: 1px solid var(--rule);
}
.site-name {
  font-size: 13px;
  font-weight: normal;
  font-style: italic;
  color: var(--white);
  letter-spacing: 0.01em;
  text-decoration: none;
}
nav { display: flex; gap: 2.2rem; }
nav a {
  font-size: 12px;
  color: var(--xdim);
  letter-spacing: 0.08em;
  text-decoration: none;
  transition: color 0.2s;
}
nav a:hover { color: var(--text); }
nav a.active { color: var(--white); }

/* ── MAIN ───────────────────────────────────────────────────── */
main {
  max-width: 820px;
  margin: 0 auto;
  padding: 4rem 2.5rem 8rem;
}

/* ── TYPE ───────────────────────────────────────────────────── */
h1 {
  font-size: clamp(2.4rem, 5vw, 4rem);
  font-weight: normal;
  font-style: italic;
  color: var(--white);
  line-height: 1.08;
  letter-spacing: -0.025em;
}
h2 {
  font-size: 11px;
  font-weight: normal;
  text-transform: uppercase;
  letter-spacing: 0.14em;
  color: var(--xdim);
}
p { max-width: 64ch; margin-bottom: 1rem; }
p:last-child { margin-bottom: 0; }
ul { list-style: none; }

hr {
  border: none;
  border-top: 1px solid var(--rule);
  margin: 1rem 0 2rem;
}

/* ── PAGE HEADER ────────────────────────────────────────────── */
.page-header { margin-bottom: 3rem; }
.page-meta {
  font-size: 12px;
  font-style: italic;
  color: var(--xdim);
  margin-top: 0.5rem;
  letter-spacing: 0.02em;
}

/* ── HERO ───────────────────────────────────────────────────── */
.hero {
  padding: 5rem 0 4rem;
  border-bottom: 1px solid var(--rule);
  margin-bottom: 4rem;
}
.hero-kicker {
  font-size: 12px;
  font-style: italic;
  color: var(--xdim);
  letter-spacing: 0.04em;
  margin-bottom: 1.8rem;
}
.hero h1 {
  font-size: clamp(3.2rem, 9vw, 6.5rem);
  margin-bottom: 2rem;
}
.hero-tagline {
  font-size: 15px;
  color: var(--dim);
  max-width: 54ch;
  line-height: 1.7;
  margin-bottom: 2.5rem;
}
.btn-group { display: flex; gap: 1rem; flex-wrap: wrap; align-items: center; }
.btn {
  display: inline-block;
  font-size: 11px;
  letter-spacing: 0.08em;
  padding: 0.45rem 1rem;
  border: 1px solid var(--rule);
  color: var(--dim);
  text-decoration: none;
  transition: border-color 0.2s, color 0.2s;
}
.btn:hover { border-color: var(--xdim); color: var(--text); }
.btn.primary {
  border-color: var(--xdim);
  color: var(--text);
}
.btn.primary:hover { border-color: var(--white); color: var(--white); }

/* ── SCHEDULE ───────────────────────────────────────────────── */
.day-block { margin-bottom: 4.5rem; }
.day-label {
  font-size: 11px;
  font-style: italic;
  color: var(--xdim);
  letter-spacing: 0.04em;
  margin-bottom: 0.3rem;
}
.day-title {
  font-size: 16px;
  font-weight: normal;
  font-style: italic;
  color: var(--white);
  letter-spacing: -0.01em;
  margin-bottom: 0.2rem;
}

.schedule-rows { margin-top: 0.5rem; }

.slot {
  display: grid;
  grid-template-columns: 56px 1fr;
  gap: 1.2rem;
  padding: 0.9rem 0;
  border-top: 1px solid var(--rule);
}
.slot:last-child { border-bottom: 1px solid var(--rule); }

.slot-time {
  font-size: 12px;
  color: var(--xdim);
  padding-top: 0.1rem;
  font-style: italic;
  letter-spacing: 0.02em;
  white-space: nowrap;
}

.slot-role {
  font-size: 10px;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  color: var(--xdim);
  margin-bottom: 0.2rem;
}
.slot-title {
  font-size: 14px;
  font-weight: normal;
  font-style: italic;
  color: var(--white);
  line-height: 1.4;
}

/* Panel / session block */
.slot-session-name {
  font-size: 13px;
  font-weight: normal;
  font-style: italic;
  color: var(--white);
  margin-bottom: 0.65rem;
  line-height: 1.4;
}
.papers { }
.papers li {
  font-size: 13px;
  color: var(--text);
  line-height: 1.65;
  padding: 0.3rem 0;
  border-top: 1px solid #1a1a1a;
}
.papers li:first-child { border-top: none; }
.paper-title {
  display: block;
  font-style: italic;
  color: var(--text);
}
.qa { color: var(--white); font-style: normal; }
.paper-speaker {
  display: block;
  font-size: 12px;
  color: var(--xdim);
  margin-top: 0.05rem;
}
.paper-speaker .online-tag {
  display: inline-block;
  font-size: 9px;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--xdim);
  border: 1px solid var(--rule);
  padding: 0 0.3em;
  margin-left: 0.4em;
  vertical-align: middle;
}

/* Break / Lunch slots */
.slot.is-break .slot-title,
.slot.is-lunch .slot-title {
  font-size: 12px;
  font-style: italic;
  color: var(--xdim);
}
.slot.is-plenary .slot-title { color: var(--white); }

/* ── SPEAKERS ────────────────────────────────────────────────── */
.speakers-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
  gap: 3rem 2.5rem;
  margin-top: 1rem;
}
.speaker-name {
  font-size: 14px;
  font-weight: normal;
  font-style: normal;
  color: var(--white);
  margin-bottom: 0.1rem;
  line-height: 1.3;
}
.speaker-affil {
  font-size: 12px;
  color: var(--xdim);
  margin-bottom: 0.5rem;
  font-style: italic;
}
.speaker-bio {
  font-size: 13px;
  color: var(--dim);
  line-height: 1.7;
}
.speaker-bio p { max-width: none; }

/* Keynote card */
.keynote-card {
  border-left: 1px solid var(--rule);
  padding-left: 1.5rem;
  margin-bottom: 3rem;
}
.keynote-card .keynote-label {
  font-size: 10px;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  color: var(--xdim);
  margin-bottom: 0.4rem;
}
.keynote-card .speaker-name { font-size: 20px; }

/* Speaker toggle */
.speaker-bio { display: none; }
.speaker-toggle {
  font-size: 10px;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--xdim);
  cursor: pointer;
  background: none;
  border: none;
  padding: 0;
  margin-top: 0.3rem;
  display: inline-block;
  font-family: var(--font);
  text-decoration: underline;
  text-underline-offset: 3px;
}
.speaker-toggle:hover { color: var(--white); }
.speaker-card.open .speaker-bio { display: block; margin-top: 0.6rem; }

/* ── ABOUT / PROSE ───────────────────────────────────────────── */
.prose p {
  font-size: 15px;
  margin-bottom: 1.3rem;
  color: var(--text);
}
.prose h2 { margin-top: 3rem; margin-bottom: 0.6rem; }
.prose ul { margin: 0.5rem 0 1.5rem; }
.prose ul li {
  font-size: 15px;
  font-style: normal;
  color: var(--text);
  padding: 0.25rem 0;
  border-top: 1px solid #141414;
  line-height: 1.6;
}
.prose ul li:first-child { border-top: none; }
.prose ul li a {
  color: var(--dim);
  font-style: normal;
  text-decoration: underline;
  text-underline-offset: 3px;
}
.prose ul li a:hover { color: var(--white); }

/* ── PRACTICAL ───────────────────────────────────────────────── */
.info-section { margin-bottom: 3.5rem; }
.info-label {
  font-size: 10px;
  text-transform: uppercase;
  letter-spacing: 0.14em;
  color: var(--xdim);
  margin-bottom: 0.3rem;
}
.info-section h2 { margin-top: 0.1rem; margin-bottom: 0.5rem; }
.info-section p,
.info-section li {
  font-size: 15px;
  color: var(--text);
}
.info-section ul { margin: 0.5rem 0 0; }
.info-section li {
  padding: 0.25rem 0;
  border-top: 1px solid var(--rule);
}
.info-section li:first-child { border-top: none; }

/* ── HOMEPAGE GRID ───────────────────────────────────────────── */
.home-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 3rem;
  margin-bottom: 4rem;
}
.home-grid h2 { margin-bottom: 0.6rem; }
.home-grid p {
  font-size: 14px;
  color: var(--dim);
  line-height: 1.7;
  margin-bottom: 0.8rem;
}
.home-grid a { font-size: 12px; font-style: italic; color: var(--dim); }
.home-grid a:hover { color: var(--white); }

/* ── FOOTER ──────────────────────────────────────────────────── */
footer {
  border-top: 1px solid var(--rule);
  padding: 1.8rem 2.5rem;
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  flex-wrap: wrap;
  gap: 1rem;
}
.footer-left, .footer-right {
  font-size: 12px;
  font-style: italic;
  color: var(--xdim);
  line-height: 1.8;
}
.footer-right a { color: var(--xdim); }
.footer-right a:hover { color: var(--white); }

/* ── RESPONSIVE ──────────────────────────────────────────────── */
@media (max-width: 680px) {
  header {
    padding: 1.5rem;
    flex-direction: column;
    align-items: flex-start;
    gap: 1rem;
  }
  nav { gap: 1.5rem; flex-wrap: wrap; }
  main { padding: 3rem 1.5rem 6rem; }
  .hero { padding: 3rem 0 2.5rem; }
  .slot { grid-template-columns: 46px 1fr; gap: 0.8rem; }
  .home-grid { grid-template-columns: 1fr; gap: 2rem; }
  .speakers-grid { grid-template-columns: 1fr; gap: 2.5rem; }
  footer { padding: 1.5rem; flex-direction: column; }
}