/* ===========================
   VARIABLES & RESET
   =========================== */
:root {
  --bg: #ffffff;
  --bg2: #f4f6fb;
  --surface: #f9fafc;
  --surface2: #eef1f8;
  --border: #dde1ed;
  --accent: #c8960a;
  --accent2: #1a8f72;
  --text: #0f1320;
  --text-muted: #4a5270;
  --text-dim: #8a93aa;
  --serif: 'DM Serif Display', Georgia, serif;
  --sans: 'DM Sans', sans-serif;
  --mono: 'DM Mono', monospace;
  --radius: 12px;
  --transition: 0.25s cubic-bezier(0.4, 0, 0.2, 1);
}

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }

body {
  background: var(--bg);
  color: var(--text);
  font-family: var(--sans);
  font-size: 16px;
  line-height: 1.65;
  overflow-x: hidden;
}

a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }

/* NAV */
.nav {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 100;
  padding: 0 2rem;
  backdrop-filter: blur(12px);
  background: rgba(255, 255, 255, 0.92);
  border-bottom: 1px solid var(--border);
}
.nav-inner {
  max-width: 1200px;
  margin: 0 auto;
  height: 60px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.nav-logo {
  font-family: var(--mono);
  font-size: 1rem;
  font-weight: 500;
  color: var(--accent);
  letter-spacing: 0.1em;
}
.nav-links {
  list-style: none;
  display: flex;
  gap: 2rem;
}
.nav-links a {
  color: var(--text-muted);
  font-size: 0.875rem;
  font-weight: 500;
  letter-spacing: 0.03em;
  transition: color var(--transition);
}
.nav-links a:hover { color: var(--text); text-decoration: none; }

/* HERO */
.hero {
  position: relative;
  min-height: 60vh;
  display: flex;
  flex-direction: column;
  justify-content: center;
  padding: 70px 1rem 1rem;
  overflow: hidden;
  background: linear-gradient(160deg, #f0f4ff 0%, #ffffff 60%);
}
.hero-bg {
  position: absolute;
  inset: 0;
  z-index: 0;
}
#graph-canvas {
  width: 100%;
  height: 100%;
  opacity: 0.18;
}
.hero-content {
  position: relative;
  z-index: 1;
  max-width: 1200px;
  margin: 0 auto;
  width: 100%;
  padding: 1.5rem 0 1rem;
}
.badge {
  display: inline-block;
  font-family: var(--mono);
  font-size: 0.75rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--accent);
  border: 1px solid var(--accent);
  padding: 0.35em 0.85em;
  border-radius: 100px;
  margin-bottom: 1.5rem;
  opacity: 0;
  animation: fadeUp 0.7s 0.2s forwards;
}
.hero-title {
  font-family: var(--serif);
  font-size: clamp(2.5rem, 6vw, 5rem);
  line-height: 1.1;
  color: var(--text);
  margin-bottom: 0.5rem;
  opacity: 0;
  animation: fadeUp 0.7s 0.4s forwards;
}
.hero-title em {
  font-style: italic;
  color: var(--accent2);
}
.hero-sub {
  font-size: 1.15rem;
  color: var(--text-muted);
  max-width: 600px;
  margin-bottom: 2.5rem;
  opacity: 0;
  animation: fadeUp 0.7s 0.6s forwards;
}
.hero-cta {
  display: flex;
  gap: 1rem;
  flex-wrap: wrap;
  opacity: 0;
  animation: fadeUp 0.7s 0.8s forwards;
}
.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.75em 1.75em;
  border-radius: 8px;
  font-size: 0.9rem;
  font-weight: 600;
  letter-spacing: 0.02em;
  transition: all var(--transition);
  cursor: pointer;
  border: none;
}
.btn-primary {
  background: var(--accent);
  color: #ffffff;
}
.btn-primary:hover { background: #a87a08; transform: translateY(-2px); text-decoration: none; }
.btn-outline {
  background: transparent;
  color: var(--text);
  border: 1px solid #9aa0b8;
}
.btn-outline:hover { border-color: var(--text-muted); background: var(--surface2); text-decoration: none; }

.hero-pillars {
  position: relative;
  z-index: 1;
  max-width: 1200px;
  margin: 4rem auto 0;
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1px;
  background: var(--border);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
  opacity: 0;
  animation: fadeUp 0.7s 1s forwards;
}
.pillar {
  background: var(--surface);
  padding: 1.5rem 2rem;
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
  transition: background var(--transition);
}
.pillar:hover { background: var(--surface2); }
.pillar-num {
  font-family: var(--mono);
  font-size: 0.7rem;
  color: var(--accent);
  letter-spacing: 0.1em;
}
.pillar-label {
  font-weight: 600;
  font-size: 0.95rem;
  color: var(--text);
}

/* SECTIONS */
.section { padding: 6rem 2rem; }
.section-dark { background: var(--bg2); }
.container { max-width: 1200px; margin: 0 auto; }
.section-label {
  font-family: var(--mono);
  font-size: 0.75rem;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  color: var(--accent2);
  margin-bottom: 0.75rem;
}
.section h2 {
  font-family: var(--serif);
  font-size: clamp(1.75rem, 3.5vw, 2.75rem);
  line-height: 1.2;
  color: var(--text);
  margin-bottom: 2rem;
}
.section-intro {
  color: var(--text-muted);
  max-width: 640px;
  margin-bottom: 3rem;
  font-size: 1.05rem;
}

/* OVERVIEW */
.overview-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 2rem;
  align-items: start;
}
.overview-text p {
  color: var(--text-muted);
  margin-bottom: 1.25rem;
  font-size: 1.02rem;
}
.overview-cards {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1rem;
}
.info-card {
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.5rem;
  transition: border-color var(--transition), transform var(--transition), box-shadow var(--transition);
}
.info-card:hover {
  border-color: var(--accent2);
  transform: translateY(-2px);
  box-shadow: 0 4px 20px rgba(26, 143, 114, 0.1);
}
.info-icon { font-size: 1.5rem; margin-bottom: 0.75rem; }
.info-card h3 { font-size: 0.9rem; font-weight: 600; margin-bottom: 0.5rem; color: var(--text); }
.info-card p { font-size: 0.85rem; color: var(--text-muted); line-height: 1.5; }

/* SCHEDULE */
.schedule { display: flex; flex-direction: column; gap: 1.5rem; }
.schedule-block {
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
  transition: border-color var(--transition), box-shadow var(--transition);
}
.schedule-block:hover {
  border-color: var(--text-dim);
  box-shadow: 0 4px 16px rgba(0,0,0,0.06);
}
.schedule-block--highlight { border-color: var(--accent2); }
.schedule-block--highlight .block-part { color: var(--accent2); }
.block-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 1.25rem 1.75rem;
  border-bottom: 1px solid var(--border);
  background: var(--surface2);
}
.block-meta { display: flex; align-items: center; gap: 1rem; }
.block-part {
  font-family: var(--mono);
  font-size: 0.7rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--accent);
}
.block-time {
  font-family: var(--mono);
  font-size: 0.8rem;
  color: var(--text-dim);
  background: var(--bg);
  border: 1px solid var(--border);
  padding: 0.2em 0.6em;
  border-radius: 4px;
}
.block-header h3 {
  font-family: var(--serif);
  font-size: 1.15rem;
  color: var(--text);
}
.block-items { padding: 0.5rem 0; }
.block-item {
  display: grid;
  grid-template-columns: 64px 1fr;
  gap: 1.25rem;
  padding: 0.85rem 1.75rem;
  border-bottom: 1px solid var(--border);
  align-items: start;
  transition: background var(--transition);
}
.block-item:last-child { border-bottom: none; }
.block-item:hover { background: var(--surface); }
.item-time {
  font-family: var(--mono);
  font-size: 0.75rem;
  color: var(--text-dim);
  padding-top: 0.15rem;
  white-space: nowrap;
}
.item-content strong {
  display: block;
  font-size: 0.9rem;
  color: var(--text);
  margin-bottom: 0.2rem;
}
.item-content p { font-size: 0.82rem; color: var(--text-muted); line-height: 1.5; }

/* MATERIALS */
.materials-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1rem;
}
.material-card {
  display: flex;
  align-items: center;
  gap: 1.25rem;
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.5rem;
  transition: all var(--transition);
  color: var(--text);
}
.material-card:hover:not(.material-card--soon) {
  border-color: var(--accent);
  transform: translateY(-2px);
  box-shadow: 0 4px 20px rgba(200, 150, 10, 0.12);
  text-decoration: none;
}
.material-card--soon { cursor: default; opacity: 0.6; }
.material-icon { font-size: 2rem; flex-shrink: 0; }
.material-info { flex: 1; }
.material-info h3 { font-size: 0.95rem; font-weight: 600; margin-bottom: 0.35rem; color: var(--text); }
.material-info p { font-size: 0.82rem; color: var(--text-muted); line-height: 1.45; }
.material-arrow { font-size: 1.25rem; color: var(--accent); flex-shrink: 0; }
.material-badge {
  font-family: var(--mono);
  font-size: 0.65rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--text-dim);
  border: 1px solid var(--border);
  padding: 0.3em 0.7em;
  border-radius: 100px;
  white-space: nowrap;
  flex-shrink: 0;
}

/* ORGANIZERS */
.organizers-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.25rem;
}
.organizer-card {
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.75rem;
  display: flex;
  flex-direction: column;
  gap: 1rem;
  transition: border-color var(--transition), transform var(--transition), box-shadow var(--transition);
}
.organizer-card:hover {
  border-color: var(--accent2);
  transform: translateY(-3px);
  box-shadow: 0 6px 24px rgba(26, 143, 114, 0.1);
}
.organizer-avatar {
  width: 52px;
  height: 52px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--accent), var(--accent2));
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: var(--mono);
  font-size: 0.85rem;
  font-weight: 500;
  color: #ffffff;
  flex-shrink: 0;
}
.organizer-info h3 {
  font-family: var(--serif);
  font-size: 1.1rem;
  margin-bottom: 0.2rem;
  color: var(--text);
}
.organizer-role {
  font-family: var(--mono);
  font-size: 0.72rem;
  color: var(--accent2);
  letter-spacing: 0.05em;
  margin-bottom: 0.75rem;
}
.organizer-info p {
  font-size: 0.82rem;
  color: var(--text-muted);
  line-height: 1.55;
  margin-bottom: 1rem;
}
.organizer-links { display: flex; gap: 1rem; flex-wrap: wrap; }
.organizer-links a {
  font-size: 0.78rem;
  font-family: var(--mono);
  color: var(--text-muted);
  transition: color var(--transition);
}
.organizer-links a:hover { color: var(--accent); text-decoration: none; }

/* FOOTER */
.footer {
  background: var(--bg2);
  border-top: 1px solid var(--border);
  padding: 3rem 2rem;
}
.footer-inner {
  display: flex;
  justify-content: space-between;
  align-items: start;
  gap: 2rem;
  flex-wrap: wrap;
}
.footer-left { display: flex; flex-direction: column; gap: 0.75rem; }
.footer-left p { font-size: 0.82rem; color: var(--text-dim); line-height: 1.65; }
.footer-right { text-align: right; }
.footer-right p { font-size: 0.82rem; color: var(--text-dim); margin-bottom: 0.4rem; }
.footer-right a { color: var(--text-muted); }
.footer-right a:hover { color: var(--accent); }

/* ANIMATIONS */
@keyframes fadeUp {
  from { opacity: 0; transform: translateY(20px); }
  to { opacity: 1; transform: translateY(0); }
}

/* RESPONSIVE */
@media (max-width: 900px) {
  .hero-pillars { grid-template-columns: repeat(2, 1fr); }
  .overview-grid { grid-template-columns: 1fr; gap: 2.5rem; }
  .organizers-grid { grid-template-columns: repeat(2, 1fr); }
  .materials-grid { grid-template-columns: 1fr; }
}
@media (max-width: 640px) {
  .nav-links { display: none; }
  .hero-pillars { grid-template-columns: 1fr 1fr; }
  .overview-cards { grid-template-columns: 1fr; }
  .organizers-grid { grid-template-columns: 1fr; }
  .block-header { flex-direction: column; align-items: flex-start; gap: 0.5rem; }
  .footer-inner { flex-direction: column; }
  .footer-right { text-align: left; }
}