/* Layout: one long page on black, after the symposium key visual.
   Programme as a timeline (time | content); parallel sessions side by side
   on wide screens. Session pairs take the colour of one circle trail:
   1–2 red, 3–4 pink, 5–6 green. */
:root {
  --bg: #000;
  --surface: #0e0c0f;
  --fg: #fff;
  --muted: #b3acb5;
  --faint: #7d7680;
  --line: #2a252c;
  --red: #dc2f27;
  --red-text: #ff6a60;
  --pink: #efabec;
  --green: #00ffa2;
  --font: "Montserrat", "Helvetica Neue", Arial, sans-serif;
  --step--1: 0.875rem;
  --step-0: 1rem;
  --step-1: 1.1875rem;
  --step-2: 1.5rem;
  --step-3: clamp(1.75rem, 1.2rem + 2.2vw, 2.5rem);
  --step-4: clamp(2.1rem, 1.2rem + 4vw, 4.25rem);
  --nav-h: 3rem;
  color-scheme: dark;
}

*, *::before, *::after { box-sizing: border-box; }
html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }
@media (prefers-reduced-motion: reduce) { html { scroll-behavior: auto; } }

body {
  margin: 0;
  background: var(--bg);
  color: var(--fg);
  font-family: var(--font);
  font-size: var(--step-0);
  line-height: 1.6;
  font-variant-numeric: lining-nums;
}
body::before {
  content: ""; position: fixed; inset: 0 0 auto;
  height: env(safe-area-inset-top, 0px); z-index: 10; background: var(--bg);
}
img { max-width: 100%; height: auto; display: block; }
a { color: inherit; }
a:focus-visible { outline: 2px solid var(--green); outline-offset: 3px; border-radius: 2px; }
h1, h2, h3, h4 { line-height: 1.2; text-wrap: balance; margin: 0; }
p { margin: 0; }

.wrap {
  width: 100%;
  max-width: 72rem;
  margin-inline: auto;
  padding-left: max(16px, env(safe-area-inset-left, 0px));
  padding-right: max(16px, env(safe-area-inset-right, 0px));
}
@media (min-width: 48rem) {
  .wrap {
    padding-left: max(32px, env(safe-area-inset-left, 0px));
    padding-right: max(32px, env(safe-area-inset-right, 0px));
  }
}

.skip { position: absolute; left: -9999px; }
.skip:focus { left: 16px; top: 16px; z-index: 20; background: var(--fg); color: var(--bg); padding: .5rem .75rem; }

[id] { scroll-margin-top: calc(var(--nav-h) + env(safe-area-inset-top, 0px) + 1rem); }

/* ---- Top navigation ---- */
.topnav {
  position: sticky; top: env(safe-area-inset-top, 0px); z-index: 5;
  background: rgba(0, 0, 0, .92);
  -webkit-backdrop-filter: blur(8px); backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--line);
}
.topnav__inner { display: flex; align-items: center; justify-content: space-between; gap: 1rem; min-height: var(--nav-h); }
.topnav__home { font-weight: 700; font-size: var(--step--1); text-decoration: none; white-space: nowrap; }
.topnav ul { display: flex; gap: 1.25rem; list-style: none; margin: 0; padding: 0; overflow-x: auto; scrollbar-width: none; }
.topnav ul::-webkit-scrollbar { display: none; }
.topnav ul a {
  font-size: .75rem; font-weight: 600; letter-spacing: .08em; text-transform: uppercase;
  text-decoration: none; color: var(--muted); white-space: nowrap; padding-block: .75rem; display: block;
}
.topnav ul a:hover { color: var(--fg); }
@media (max-width: 40rem) {
  .topnav__home { display: none; }
  .topnav ul { width: 100%; justify-content: space-between; gap: .5rem; }
  .topnav ul a { font-size: .6875rem; letter-spacing: .04em; }
}

/* ---- Hero ---- */
.hero { padding-block: 2rem 2.5rem; overflow: hidden; }
.hero__inner { display: grid; gap: 1.5rem; }
.hero__title { font-size: var(--step-4); font-weight: 700; letter-spacing: -.01em; line-height: 1.1; }
.hero__trails { width: 100%; }
.hero__meta { display: grid; gap: .1rem; font-size: var(--step-1); line-height: 1.35; }
.hero__meta strong { font-weight: 600; }
@media (min-width: 48rem) {
  .hero { padding-block: 3rem 3.5rem; }
  .hero__inner { grid-template-areas: "stack" "meta"; gap: 2rem; }
  .hero__title, .hero__trails { grid-area: stack; }
  .hero__meta { grid-area: meta; }
  .hero__title { align-self: start; z-index: 1; padding-top: .5rem; }
  .hero__trails { margin-top: 1.5rem; }
}

/* ---- Sections ---- */
.section { padding-block: 3rem; border-top: 1px solid var(--line); }
.section__head { display: flex; align-items: baseline; justify-content: space-between; gap: 1rem; margin-bottom: 2rem; }
.section__title { font-size: var(--step-3); font-weight: 700; }
.eyebrow { font-size: .75rem; font-weight: 600; letter-spacing: .1em; text-transform: uppercase; color: var(--muted); }

.dot { display: inline-block; width: .8em; height: .8em; border-radius: 50%; background: var(--c, var(--fg)); flex: none; }
.c-red { --c: var(--red); --c-text: var(--red-text); }
.c-pink { --c: var(--pink); --c-text: var(--pink); }
.c-green { --c: var(--green); --c-text: var(--green); }

/* ---- Programme ---- */
.timeline { list-style: none; margin: 0; padding: 0; }
.slot {
  display: grid; grid-template-columns: 1fr; gap: .5rem;
  padding-block: 1.25rem; border-bottom: 1px solid var(--line);
}
.slot:first-child { padding-top: 0; }
.slot__time { font-variant-numeric: tabular-nums; font-weight: 600; font-size: var(--step--1); color: var(--muted); white-space: nowrap; }
.slot__body { min-width: 0; }
@media (min-width: 40rem) {
  .slot { grid-template-columns: 8.5rem 1fr; gap: 1.5rem; }
  .slot__time { padding-top: .15rem; }
}

.slot--break .slot__label { color: var(--muted); font-weight: 500; }
.slot--break .slot__note { color: var(--faint); font-size: var(--step--1); }
.slot--break { padding-block: .9rem; }

.slot__label { font-size: var(--step-1); font-weight: 600; }
.plenary { display: grid; gap: .9rem; margin-top: .6rem; }
.plenary__item { display: grid; gap: .1rem; }
.plenary__role { font-size: .75rem; font-weight: 600; letter-spacing: .1em; text-transform: uppercase; color: var(--muted); }
.plenary__name { font-weight: 600; }
.plenary__name a { text-decoration-color: var(--faint); text-underline-offset: .2em; }
.plenary__name a:hover { text-decoration-color: var(--fg); }
.plenary__aff { color: var(--muted); font-size: var(--step--1); }
.plenary__talk { font-style: italic; }
.close-list { list-style: none; margin: .4rem 0 0; padding: 0; color: var(--muted); }

.sessions { display: grid; gap: 1rem; }
@media (min-width: 56rem) { .sessions { grid-template-columns: 1fr 1fr; } }

.session { background: var(--surface); padding: 1.25rem 1.25rem 1rem; min-width: 0; }
.session__head { display: flex; align-items: center; gap: .6rem; }
.session__title { font-size: var(--step-1); font-weight: 700; }
.session__title a { text-decoration: none; }
.session__title a:hover { color: var(--c-text); }
.session__chair { color: var(--muted); font-size: var(--step--1); margin-top: .25rem; }
.talks { list-style: none; margin: .9rem 0 0; padding: 0; }
.talks li + li { border-top: 1px solid var(--line); }
.talks a { display: grid; gap: .1rem; padding-block: .65rem; text-decoration: none; }
.talks__name { font-weight: 600; }
.talks__title { color: var(--muted); font-size: var(--step--1); line-height: 1.45; }
.talks a:hover .talks__name, .talks a:focus-visible .talks__name { color: var(--c-text); }

/* ---- Foreword and keynote ---- */
.feature { display: grid; gap: 1.5rem; }
@media (min-width: 48rem) { .feature { grid-template-columns: 12rem minmax(0, 42rem); gap: 2.5rem; } }
.feature__photo { width: 9rem; aspect-ratio: 1; border-radius: 50%; object-fit: cover; }
@media (min-width: 48rem) { .feature__photo { width: 12rem; } }
.feature__name { font-size: var(--step-2); font-weight: 700; }
.feature__role { color: var(--muted); margin-top: .25rem; }
.feature__talk { margin-top: 1rem; font-size: var(--step-1); font-weight: 600; }
.feature__talk span { display: block; font-size: .75rem; letter-spacing: .1em; text-transform: uppercase; color: var(--muted); font-weight: 600; margin-bottom: .2rem; }
.prose { display: grid; gap: 1rem; margin-top: 1.5rem; max-width: 42rem; }

/* ---- Presenters ---- */
.group + .group { margin-top: 3.5rem; }
.group__head { display: grid; gap: .3rem; padding-bottom: 1rem; border-bottom: 1px solid var(--c); }
.group__title { display: flex; align-items: center; gap: .6rem; font-size: var(--step-2); font-weight: 700; }
.group__meta { color: var(--muted); font-size: var(--step--1); font-variant-numeric: tabular-nums; }

.entry { padding-block: 2rem; border-bottom: 1px solid var(--line); display: grid; gap: 1rem; max-width: 46rem; }
.entry__name { font-size: var(--step-1); font-weight: 700; }
.entry__inst { color: var(--muted); font-size: var(--step--1); margin-top: .15rem; }
.entry__title { font-size: var(--step-1); font-weight: 600; line-height: 1.35; color: var(--c-text); text-wrap: balance; }
.entry__block { display: grid; gap: .75rem; }
.entry__block h4 { font-size: .75rem; font-weight: 600; letter-spacing: .1em; text-transform: uppercase; color: var(--muted); }
.entry__bio { color: var(--muted); }
.entry__back { font-size: var(--step--1); color: var(--faint); text-decoration: none; justify-self: start; }
.entry__back:hover { color: var(--fg); }
.entry:target .entry__name { color: var(--c-text); }

/* ---- Footer ---- */
.footer { border-top: 1px solid var(--line); padding-block: 2.5rem 3rem; }
.footer__inner { display: grid; gap: 2rem; }
.footer__ack { color: var(--muted); font-size: var(--step--1); max-width: 42rem; }
.footer__logos { width: 100%; max-width: 40rem; }

.loading, .error { padding-block: 3rem; color: var(--muted); }