/* ===== Penrose-fest @ 95 ===== */

@import url('https://fonts.googleapis.com/css2?family=IM+Fell+English:ital@0;1&family=EB+Garamond:ital,wght@0,400;0,500;1,400;1,500&family=Space+Mono:wght@400;700&display=swap');

/* --- Tokens --- */
:root {
  --parchment:   #f2ece0;
  --parchment-d: #e8dfcc;
  --stone:       #dfd5bc;
  --ink:         #1c1f2c;
  --ink-mid:     #3b3720;
  --ink-soft:    #5e5840;
  --gold:        #876825;
  --gold-light:  #ad8c3e;
  --gold-faint:  rgba(135,104,37,0.1);
  --rule:        rgba(185,162,100,0.3);

  --display:  'IM Fell English', Georgia, serif;
  --body:     'EB Garamond', Georgia, serif;
  --mono:     'Space Mono', 'Courier New', monospace;

  --max-w: 860px;
  --side:  clamp(1.25rem, 5vw, 3rem);
}

/* --- Reset --- */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; font-size: 18px; }

body {
  background-color: var(--parchment);
  color: var(--ink);
  font-family: var(--body);
  line-height: 1.78;
  min-height: 100vh;
}

/* --- Tiling background layer (inline SVG) --- */
#tiling-bg {
  position: fixed;
  inset: 0;
  width: 100%;
  height: 100%;
  pointer-events: none;
  z-index: 0;
  opacity: 1;
  overflow: hidden;
}
body > * { position: relative; z-index: 1; }
body > #tiling-bg { z-index: 0; }

/* --- Typography --- */
h1 {
  font-family: var(--display);
  font-weight: 400;
  line-height: 1.1;
  color: var(--ink);
}
h2, h3 {
  font-family: var(--body);
  font-weight: 400;
  line-height: 1.2;
  color: var(--ink);
}
h4 {
  font-family: var(--mono);
  font-size: 0.72rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--gold);
  font-weight: 400;
  font-style: normal;
}

h1 { font-size: clamp(2.6rem, 6.5vw, 4.4rem); letter-spacing: -0.01em; }
h2 { font-size: clamp(1.65rem, 3.5vw, 2.5rem); letter-spacing: 0.01em; }
h3 { font-size: clamp(1.15rem, 2.5vw, 1.6rem); }

p { margin-bottom: 1.1em; }
p:last-child { margin-bottom: 0; }

a { color: var(--gold); text-decoration: none; border-bottom: 1px solid transparent; transition: border-color 0.2s, color 0.2s; }
a:hover, a:focus { border-bottom-color: var(--gold); }
a:focus-visible { outline: 2px solid var(--gold); outline-offset: 3px; border-radius: 2px; }

strong { font-weight: 600; }

/* --- Layout --- */
.container {
  max-width: var(--max-w);
  margin-inline: auto;
  padding-inline: var(--side);
}

section {
  padding-block: clamp(3rem, 8vw, 6rem);
  position: relative;
}

section + section::before {
  content: '';
  display: block;
  position: absolute;
  top: 0;
  left: var(--side);
  right: var(--side);
  height: 1px;
  background: var(--rule);
}

/* ===== NAV ===== */
#site-nav {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(244,239,229,0.93);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--rule);
}

.nav-inner {
  max-width: var(--max-w);
  margin-inline: auto;
  padding-inline: var(--side);
  height: 3.2rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
}

.nav-logo {
  display: flex;
  align-items: center;
  gap: 0.55rem;
  font-family: var(--display);
  font-size: 1rem;
  font-optical-sizing: auto;
  color: var(--ink);
  border-bottom: none;
  white-space: nowrap;
  letter-spacing: 0.01em;
}
.nav-logo svg { flex-shrink: 0; }

.nav-links {
  display: flex;
  gap: 1.8rem;
  list-style: none;
  font-family: var(--mono);
  font-size: 0.68rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
}
.nav-links a {
  color: var(--ink-soft);
  border-bottom: none;
  transition: color 0.2s;
}
.nav-links a:hover { color: var(--gold); }

.nav-toggle {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  padding: 0.25rem;
  color: var(--ink);
}
.nav-toggle span {
  display: block;
  width: 22px;
  height: 1.5px;
  background: currentColor;
  margin-block: 4.5px;
  transition: transform 0.25s, opacity 0.25s;
}
.nav-toggle[aria-expanded="true"] span:nth-child(1) { transform: translateY(6px) rotate(45deg); }
.nav-toggle[aria-expanded="true"] span:nth-child(2) { opacity: 0; }
.nav-toggle[aria-expanded="true"] span:nth-child(3) { transform: translateY(-6px) rotate(-45deg); }

@media (max-width: 600px) {
  .nav-toggle { display: block; }
  .nav-links {
    display: none;
    position: absolute;
    top: 100%;
    left: 0; right: 0;
    background: rgba(244,239,229,0.98);
    flex-direction: column;
    padding: 1.2rem var(--side) 1.8rem;
    gap: 1.1rem;
    border-bottom: 1px solid var(--rule);
  }
  .nav-links.open { display: flex; }
}

/* ===== HERO ===== */
#hero {
  padding-block: clamp(4rem, 10vw, 8rem) clamp(3rem, 6vw, 5rem);
  text-align: center;
  overflow: hidden;
}

.hero-emblem {
  margin-inline: auto;
  margin-bottom: 2.2rem;
  display: block;
}

/* Geometric kite frame behind title area */
.hero-geo-frame {
  position: relative;
  display: inline-block;
  margin-bottom: 0.3rem;
}
.hero-geo-frame svg {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  pointer-events: none;
}

.hero-title {
  font-size: clamp(2.8rem, 7.5vw, 5.2rem);
  font-weight: 300;
  font-optical-sizing: auto;
  letter-spacing: -0.01em;
  color: var(--ink);
  position: relative;
}
.hero-title .at { color: var(--gold); font-style: italic; }
.hero-title .num { font-variant-numeric: oldstyle-nums; }

.hero-sub {
  font-family: var(--mono);
  font-size: 0.72rem;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--gold);
  margin-top: 0.6rem;
  margin-bottom: 2.8rem;
}

/* Geometric diamond rule */
.hero-rule {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.8rem;
  margin-block: 2rem;
}
.hero-rule::before,
.hero-rule::after {
  content: '';
  display: block;
  flex: 1;
  max-width: 4rem;
  height: 1px;
  background: var(--gold);
  opacity: 0.4;
}
.hero-rule-diamond {
  width: 7px;
  height: 7px;
  background: var(--gold);
  transform: rotate(45deg);
  opacity: 0.7;
  flex-shrink: 0;
}

.hero-dates {
  font-family: var(--display);
  font-size: 1.3rem;
  font-style: italic;
  font-optical-sizing: auto;
  color: var(--ink-mid);
  margin-bottom: 0.35rem;
}

.hero-venue {
  font-family: var(--mono);
  font-size: 0.72rem;
  letter-spacing: 0.1em;
  color: var(--ink-soft);
  text-transform: uppercase;
  margin-bottom: 2.8rem;
}

.hero-desc {
  max-width: 600px;
  margin-inline: auto;
  font-size: 1.08rem;
  color: var(--ink-mid);
  text-align: left;
}
.hero-desc p + p { margin-top: 1em; }

/* --- Organisers --- */
.organisers {
  margin-top: 3rem;
  text-align: left;
  max-width: 600px;
  margin-inline: auto;
}
.organisers > h3 {
  font-family: var(--mono);
  font-size: 0.7rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--gold);
  margin-bottom: 1.1rem;
  font-weight: 400;
}
.organiser-list {
  list-style: none;
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
  gap: 0.75rem 1.8rem;
}
.organiser-list li {
  font-size: 1rem;
  color: var(--ink-mid);
}
.organiser-list .affil {
  display: block;
  font-size: 0.82rem;
  color: var(--ink-soft);
  font-style: italic;
  margin-top: 0.05rem;
}

/* ===== SECTION LABELS ===== */
.section-label {
  font-family: var(--mono);
  font-size: 0.68rem;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--gold);
  margin-bottom: 0.6rem;
  display: flex;
  align-items: center;
  gap: 0.55rem;
}
/* Tiny rhombus before section labels */
.section-label::before {
  content: '';
  display: inline-block;
  width: 5px;
  height: 5px;
  background: var(--gold);
  transform: rotate(45deg);
  opacity: 0.8;
  flex-shrink: 0;
}

.section-title { margin-bottom: 2.5rem; }

/* ===== PROGRAMME ===== */
.day-tabs {
  display: flex;
  gap: 0;
  margin-bottom: 2rem;
  border-bottom: 1px solid var(--rule);
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
}
.day-tab {
  background: none;
  border: none;
  border-bottom: 2px solid transparent;
  padding: 0.55rem 1.1rem;
  font-family: var(--mono);
  font-size: 0.7rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--ink-soft);
  cursor: pointer;
  white-space: nowrap;
  transition: color 0.2s, border-color 0.2s;
  margin-bottom: -1px;
}
.day-tab.active, .day-tab:hover {
  color: var(--ink);
  border-bottom-color: var(--gold);
}

.day-panel { display: none; }
.day-panel.active { display: block; }

/* Schedule table */
.schedule {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.97rem;
}
.schedule thead th {
  font-family: var(--mono);
  font-size: 0.65rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--gold);
  text-align: left;
  padding: 0 0 0.6rem;
  border-bottom: 1px solid var(--rule);
}
.schedule thead th:first-child { width: 5.5rem; }

.schedule tbody tr + tr td { border-top: 1px solid var(--rule); }
.schedule td { padding: 1rem 0.5rem; vertical-align: top; }
.schedule td:first-child {
  font-family: var(--mono);
  font-size: 0.72rem;
  color: var(--ink-soft);
  white-space: nowrap;
  padding-right: 1.2rem;
  letter-spacing: 0.04em;
}

.schedule .break td {
  color: var(--ink-soft);
  /* font-style: italic; */
  /* font-size: 0.92rem; */
}

.session-type {
  font-family: var(--mono);
  font-size: 0.63rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--gold);
  display: block;
  margin-bottom: 0.25rem;
  opacity: 0.85;
}
.talk-title {
  font-family: var(--display);
  font-size: 1.08rem;
  font-optical-sizing: auto;
  color: var(--ink);
  line-height: 1.3;
}
.talk-speaker {
  font-family: var(--body);
  font-size: 0.95rem;
  color: var(--ink-soft);
  margin-top: 0.2rem;
  font-style: italic;
}

/* Abstract toggle */
.abstract-toggle {
  background: none;
  border: none;
  font-family: var(--mono);
  font-size: 0.65rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--gold);
  cursor: pointer;
  padding: 0;
  margin-top: 0.55rem;
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  transition: opacity 0.2s;
  opacity: 0.85;
}
.abstract-toggle:hover { opacity: 1; }
.abstract-toggle .arrow {
  display: inline-block;
  width: 0;
  height: 0;
  border-top: 4px solid transparent;
  border-bottom: 4px solid transparent;
  border-left: 5px solid var(--gold);
  transition: transform 0.22s;
}
.abstract-toggle[aria-expanded="true"] .arrow { transform: rotate(90deg); }

.abstract-body {
  display: none;
  margin-top: 0.8rem;
  padding: 0.9rem 1.1rem;
  border-left: 1px solid rgba(154,122,56,0.35);
  font-size: 0.94rem;
  color: var(--ink-mid);
  line-height: 1.72;
  background: rgba(154,122,56,0.03);
  font-family: var(--body);
}
.abstract-body.open { display: block; }

/* ===== VENUE & TRAVEL ===== */
.maps-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 1.5rem;
  margin-block: 2rem;
}

.map-figure { margin: 0; }
.map-figure figcaption {
  font-family: var(--mono);
  font-size: 0.68rem;
  color: var(--ink-soft);
  margin-top: 0.55rem;
  letter-spacing: 0.06em;
  text-transform: uppercase;
}

.map-thumb {
  width: 100%;
  aspect-ratio: 4/3;
  object-fit: cover;
  display: block;
  cursor: zoom-in;
  border: 1px solid var(--rule);
  transition: box-shadow 0.25s;
  background: var(--stone);
}
.map-thumb:hover { box-shadow: 0 6px 24px rgba(26,31,46,0.14); }

.map-placeholder {
  width: 100%;
  aspect-ratio: 4/3;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  background: var(--stone);
  border: 1px dashed rgba(154,122,56,0.45);
  color: var(--gold);
  font-family: var(--mono);
  font-size: 0.68rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  cursor: zoom-in;
  gap: 0.6rem;
  opacity: 0.85;
}
.map-placeholder svg { opacity: 0.45; }

/* Lightbox */
#lightbox {
  display: none;
  position: fixed;
  inset: 0;
  background: rgba(26,31,46,0.9);
  z-index: 200;
  align-items: center;
  justify-content: center;
  padding: 2rem;
  cursor: zoom-out;
}
#lightbox.open { display: flex; }
#lightbox img {
  max-width: 100%;
  max-height: 90vh;
  object-fit: contain;
  box-shadow: 0 12px 60px rgba(0,0,0,0.5);
  border: 1px solid rgba(255,255,255,0.08);
}
#lightbox-close {
  position: absolute;
  top: 1.2rem; right: 1.5rem;
  background: none;
  border: none;
  color: rgba(255,255,255,0.6);
  font-size: 1.6rem;
  cursor: pointer;
  line-height: 1;
  font-family: var(--mono);
  transition: color 0.15s;
}
#lightbox-close:hover { color: #fff; }

/* Travel cards */
.travel-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 1.8rem 2.2rem;
  margin-top: 2rem;
}
.travel-card h4 { margin-bottom: 0.65rem; }
.travel-card p { font-size: 0.97rem; color: var(--ink-mid); }

/* ===== GEOMETRIC DIVIDERS ===== */
.geo-divider {
  display: flex;
  align-items: center;
  justify-content: center;
  padding-block: 0.5rem;
}

/* ===== FOOTER ===== */
footer {
  border-top: 1px solid var(--rule);
  padding-block: 2.8rem;
  text-align: center;
  font-family: var(--mono);
  font-size: 0.68rem;
  color: var(--ink-soft);
  letter-spacing: 0.06em;
}
footer .footer-emblem { margin-bottom: 1.2rem; opacity: 0.45; }
footer a { color: var(--ink-soft); border-bottom-color: transparent; }
footer a:hover { color: var(--gold); }
footer .sep { margin-inline: 0.9rem; opacity: 0.35; }
footer p { margin-bottom: 0.4em; }
footer p:last-child { margin-bottom: 0; }

/* ===== PRINT ===== */
@media print {
  #tiling-bg, #site-nav, footer, .day-tabs, .abstract-toggle, .geo-divider { display: none !important; }
  .day-panel { display: block !important; }
  .abstract-body { display: block !important; border-left: 1px solid #ccc; }
  section { padding-block: 1.5rem; break-inside: avoid; }
  section + section::before { display: none; }
  a { color: inherit; border: none; }
  h2 { margin-bottom: 0.8rem; }
  .schedule td { padding: 0.5rem 0.3rem; }
  .hero-geo-frame svg { display: none; }
  @page { margin: 2cm; }
}

/* ===== UTILITIES ===== */
.visually-hidden {
  position: absolute;
  width: 1px; height: 1px;
  padding: 0; margin: -1px;
  overflow: hidden; clip: rect(0,0,0,0);
  white-space: nowrap; border: 0;
}