:root {
  --bg: #fbfaf7;
  --bg-alt: #f3f1eb;
  --ink: #14161c;
  --ink-soft: #4a4f5a;
  --ink-muted: #7a8090;
  --line: #e6e3da;
  --accent: #1c4cff;
  --accent-2: #ff5b3a;
  --accent-soft: #e8efff;
  --grad-a: #1c4cff;
  --grad-b: #7b3dff;
  --grad-c: #ff5b3a;
  --max: 1120px;
  --radius: 14px;
  --shadow: 0 1px 2px rgba(20, 22, 28, 0.04), 0 8px 28px rgba(20, 22, 28, 0.06);
  --shadow-lg: 0 4px 14px rgba(20, 22, 28, 0.06), 0 24px 56px rgba(20, 22, 28, 0.12);
}

* { box-sizing: border-box; }
html, body { margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
body {
  background: var(--bg);
  color: var(--ink);
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  font-size: 16px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

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

img { max-width: 100%; display: block; }

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

/* ----- NAV ----- */
.nav {
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(251, 250, 247, 0.85);
  backdrop-filter: saturate(180%) blur(14px);
  -webkit-backdrop-filter: saturate(180%) blur(14px);
  border-bottom: 1px solid var(--line);
}
.nav-inner {
  max-width: var(--max);
  margin: 0 auto;
  padding: 14px 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}
.brand {
  display: inline-flex;
  align-items: baseline;
  gap: 8px;
  color: var(--ink);
  text-decoration: none;
  font-weight: 700;
}
.brand:hover { text-decoration: none; }
.brand-mark {
  font-size: 1.1rem;
  letter-spacing: -0.01em;
  background: linear-gradient(120deg, var(--grad-a), var(--grad-b) 60%, var(--grad-c));
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}
.brand-sub {
  font-size: 0.78rem;
  color: var(--ink-muted);
  font-weight: 500;
  letter-spacing: 0.04em;
  text-transform: uppercase;
}
.nav nav {
  display: flex;
  gap: 22px;
  flex-wrap: wrap;
}
.nav nav a {
  color: var(--ink-soft);
  text-decoration: none;
  font-size: 0.92rem;
  font-weight: 500;
  transition: color 0.15s ease;
}
.nav nav a:hover { color: var(--ink); }

/* ----- HERO ----- */
.hero {
  position: relative;
  padding: 88px 24px 96px;
  overflow: hidden;
}
.hero-grid {
  position: absolute;
  inset: 0;
  background-image:
    radial-gradient(circle at 18% 12%, rgba(28, 76, 255, 0.10), transparent 38%),
    radial-gradient(circle at 86% 18%, rgba(255, 91, 58, 0.08), transparent 42%),
    radial-gradient(circle at 50% 110%, rgba(123, 61, 255, 0.10), transparent 45%),
    linear-gradient(transparent 0px, transparent 39px, rgba(20, 22, 28, 0.05) 40px),
    linear-gradient(90deg, transparent 0px, transparent 39px, rgba(20, 22, 28, 0.05) 40px);
  background-size: auto, auto, auto, 40px 40px, 40px 40px;
  mask-image: linear-gradient(to bottom, black 0%, black 70%, transparent 100%);
  -webkit-mask-image: linear-gradient(to bottom, black 0%, black 70%, transparent 100%);
}
.hero-cloud {
  position: absolute;
  inset: 0;
  z-index: 0;
  pointer-events: none;
  mask-image: linear-gradient(to bottom, black 0%, black 64%, transparent 100%);
  -webkit-mask-image: linear-gradient(to bottom, black 0%, black 64%, transparent 100%);
}
.hero-inner {
  position: relative;
  z-index: 1;
  max-width: var(--max);
  margin: 0 auto;
}
.kicker {
  display: inline-flex;
  gap: 10px;
  align-items: center;
  font-size: 0.86rem;
  color: var(--ink-soft);
  margin-bottom: 22px;
}
.badge {
  display: inline-block;
  padding: 5px 11px;
  background: var(--ink);
  color: #fff;
  border-radius: 999px;
  font-weight: 600;
  font-size: 0.78rem;
  letter-spacing: 0.04em;
  text-transform: uppercase;
}
.dot { color: var(--ink-muted); }

.hero h1 {
  font-size: clamp(2.2rem, 5.5vw, 4.4rem);
  line-height: 1.04;
  letter-spacing: -0.03em;
  font-weight: 800;
  margin: 0 0 22px;
  color: var(--ink);
}
.grad {
  background: linear-gradient(120deg, var(--grad-a) 0%, var(--grad-b) 55%, var(--grad-c) 100%);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}
.lede {
  max-width: 720px;
  font-size: 1.08rem;
  color: var(--ink-soft);
  margin: 0 0 32px;
}
.meta {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 16px;
  max-width: 760px;
  margin-bottom: 36px;
}
.meta-item {
  background: #fff;
  border: 1px solid var(--line);
  padding: 14px 16px;
  border-radius: var(--radius);
  display: flex;
  flex-direction: column;
  gap: 4px;
}
.meta-label {
  font-size: 0.74rem;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--ink-muted);
  font-weight: 600;
}
.meta-value {
  font-size: 0.96rem;
  color: var(--ink);
  font-weight: 500;
}
.cta {
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
}
.btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 12px 20px;
  border-radius: 999px;
  font-weight: 600;
  font-size: 0.95rem;
  border: 1px solid transparent;
  cursor: pointer;
  transition: transform 0.12s ease, box-shadow 0.12s ease, background 0.12s ease, color 0.12s ease;
  text-decoration: none;
}
.btn.primary {
  background: var(--ink);
  color: #fff;
  box-shadow: 0 6px 24px rgba(20, 22, 28, 0.18);
}
.btn.primary:hover { transform: translateY(-1px); background: #000; text-decoration: none; }
.btn.ghost {
  background: transparent;
  color: var(--ink);
  border-color: var(--line);
}
.btn.ghost:hover { background: #fff; text-decoration: none; }
.btn.small { padding: 8px 14px; font-size: 0.86rem; }

/* ----- SECTIONS ----- */
.section {
  padding: 88px 0;
  border-top: 1px solid var(--line);
}
.section.alt {
  background: var(--bg-alt);
}
.section-head {
  margin-bottom: 36px;
  max-width: 760px;
}
.eyebrow {
  display: inline-block;
  font-size: 0.78rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--ink-muted);
  font-weight: 600;
  margin-bottom: 12px;
  font-family: 'JetBrains Mono', monospace;
}
.section h2 {
  font-size: clamp(1.7rem, 3.2vw, 2.4rem);
  letter-spacing: -0.02em;
  line-height: 1.15;
  margin: 0 0 12px;
  font-weight: 700;
}
.section-sub {
  color: var(--ink-soft);
  font-size: 1.02rem;
  margin: 0;
}
.prose p {
  max-width: 780px;
  color: var(--ink-soft);
  font-size: 1rem;
  margin: 0 0 18px;
}
.prose strong { color: var(--ink); }

/* ----- TOPICS ----- */
.topics {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 20px;
}
.topic {
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 22px 22px 24px;
  transition: transform 0.15s ease, box-shadow 0.15s ease;
}
.topic:hover { transform: translateY(-2px); box-shadow: var(--shadow); }
.topic-num {
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.78rem;
  color: var(--ink-muted);
  margin-bottom: 10px;
}
.topic h3 {
  margin: 0 0 8px;
  font-size: 1.05rem;
  letter-spacing: -0.01em;
}
.topic p {
  margin: 0;
  color: var(--ink-soft);
  font-size: 0.94rem;
}

/* ----- PEOPLE GRID ----- */
.people-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 20px;
}
.people-grid.compact {
  grid-template-columns: repeat(5, minmax(0, 1fr));
  gap: 14px;
}
.people-grid.compact .person { padding: 12px 12px 14px; gap: 10px; }
.people-grid.compact .person h4 { font-size: 0.92rem; }
.people-grid.compact .person .aff { font-size: 0.78rem; line-height: 1.35; }
.people-grid.compact .person a.weblink { font-size: 0.76rem; }
.person {
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 16px 16px 18px;
  display: flex;
  flex-direction: column;
  gap: 12px;
  transition: transform 0.15s ease, box-shadow 0.15s ease;
}
.person:hover { transform: translateY(-2px); box-shadow: var(--shadow); }
.person .photo {
  aspect-ratio: 1 / 1;
  border-radius: 10px;
  overflow: hidden;
  background: linear-gradient(135deg, #eef0f6, #dde2ee);
  position: relative;
}
.person .photo img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}
.person .photo.placeholder::after {
  content: attr(data-initials);
  position: absolute;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 2.2rem;
  font-weight: 700;
  letter-spacing: 0.02em;
  color: var(--ink-muted);
  background: linear-gradient(135deg, #eef0f6, #d8def0);
}
.person h4 {
  margin: 0;
  font-size: 1rem;
  letter-spacing: -0.01em;
  line-height: 1.25;
}
.person .aff {
  margin: -4px 0 0;
  color: var(--ink-muted);
  font-size: 0.86rem;
  line-height: 1.4;
}
.person a.weblink {
  font-size: 0.82rem;
  color: var(--accent);
  font-weight: 500;
  margin-top: auto;
}

.note {
  margin-top: 24px;
  font-size: 0.85rem;
  color: var(--ink-muted);
}

/* ----- SCHEDULE ----- */
.schedule {
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
}
.schedule-row {
  display: grid;
  grid-template-columns: 180px 1fr;
  padding: 14px 22px;
  border-top: 1px solid var(--line);
  align-items: center;
  font-size: 0.96rem;
}
.schedule-row:first-child { border-top: none; }
.schedule-row.head {
  background: var(--ink);
  color: #fff;
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.78rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}
.schedule-row .time {
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.88rem;
  color: var(--ink-soft);
}
.schedule-row.head .time { color: #fff; }
.schedule-row.break { background: #faf7f0; color: var(--ink-soft); }

/* ----- CHALLENGE ----- */
.challenge-banner {
  display: flex;
  gap: 18px;
  align-items: center;
  background: linear-gradient(120deg, #fff7ee, #fff0eb);
  border: 1px solid #f4dccd;
  border-radius: var(--radius);
  padding: 18px 22px;
  margin-bottom: 28px;
}
.banner-mark {
  font-size: 1.8rem;
  line-height: 1;
}
.challenge-banner strong { color: var(--ink); }
.tracks {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 20px;
  margin-bottom: 36px;
}
.track {
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 24px;
  display: flex;
  flex-direction: column;
  gap: 14px;
  position: relative;
  overflow: hidden;
}
.track::before {
  content: "";
  position: absolute;
  inset: 0 0 auto 0;
  height: 4px;
  background: linear-gradient(90deg, var(--grad-a), var(--grad-b), var(--grad-c));
}
.track-tag {
  display: inline-block;
  align-self: flex-start;
  background: var(--accent-soft);
  color: var(--accent);
  font-size: 0.78rem;
  font-weight: 700;
  padding: 4px 10px;
  border-radius: 999px;
  letter-spacing: 0.04em;
  text-transform: uppercase;
}
.track h3 {
  margin: 0;
  font-size: 1.2rem;
  letter-spacing: -0.01em;
  line-height: 1.25;
}
.track p {
  margin: 0;
  color: var(--ink-soft);
  font-size: 0.96rem;
}
.track-meta {
  list-style: none;
  padding: 0;
  margin: 4px 0 0;
  display: flex;
  flex-direction: column;
  gap: 6px;
  font-size: 0.9rem;
}
.track-meta li {
  display: grid;
  grid-template-columns: 92px 1fr;
  gap: 12px;
  color: var(--ink-soft);
}
.track-meta li span {
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.78rem;
  color: var(--ink-muted);
  text-transform: uppercase;
  letter-spacing: 0.06em;
}

.timeline {
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 24px 24px 18px;
}
.timeline h3 {
  margin: 0 0 14px;
  font-size: 1.1rem;
  letter-spacing: -0.01em;
}
.timeline-grid {
  display: flex;
  flex-direction: column;
  border-top: 1px solid var(--line);
}
.tl-row {
  display: grid;
  grid-template-columns: 1fr 200px;
  padding: 12px 4px;
  border-bottom: 1px solid var(--line);
  font-size: 0.95rem;
  color: var(--ink-soft);
}
.tl-row.head {
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.74rem;
  text-transform: uppercase;
  color: var(--ink-muted);
  letter-spacing: 0.08em;
  padding: 10px 4px;
}
.tl-row.hl {
  background: var(--accent-soft);
  border-radius: 8px;
  border-bottom: none;
  padding: 12px 14px;
  color: var(--accent);
}
.tl-row > div:last-child {
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.84rem;
  color: var(--ink);
}
.tl-row.hl > div:last-child { color: var(--accent); }

/* ----- CONTACT ----- */
.contact-card {
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 36px;
  display: grid;
  grid-template-columns: 1.6fr 1fr;
  gap: 36px;
}
.contact-card h2 { margin-top: 8px; }
.contact-card p { color: var(--ink-soft); }
.email a {
  font-weight: 600;
  font-size: 1.1rem;
}
.contact-side {
  display: flex;
  flex-direction: column;
  gap: 18px;
  border-left: 1px solid var(--line);
  padding-left: 36px;
}
.contact-block {
  display: flex;
  flex-direction: column;
  gap: 4px;
}

/* ----- FOOTER ----- */
.footer {
  padding: 32px 0 40px;
  border-top: 1px solid var(--line);
  background: var(--bg);
}
.footer-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 12px;
  font-size: 0.88rem;
  color: var(--ink-soft);
}
.muted { color: var(--ink-muted); }

/* ----- RESPONSIVE ----- */
@media (max-width: 980px) {
  .topics, .people-grid { grid-template-columns: repeat(3, minmax(0, 1fr)); }
  .people-grid.compact { grid-template-columns: repeat(5, minmax(0, 1fr)); }
  .tracks { grid-template-columns: 1fr; }
  .meta { grid-template-columns: repeat(2, 1fr); }
  .contact-card { grid-template-columns: 1fr; }
  .contact-side { border-left: none; border-top: 1px solid var(--line); padding-left: 0; padding-top: 24px; }
}
@media (max-width: 720px) {
  .nav-inner { flex-wrap: wrap; }
  .nav nav { gap: 14px; }
  .hero { padding: 56px 24px 72px; }
  .section { padding: 64px 0; }
  .topics, .people-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .people-grid.compact { grid-template-columns: repeat(3, minmax(0, 1fr)); }
  .schedule-row { grid-template-columns: 110px 1fr; padding: 12px 16px; font-size: 0.92rem; }
  .tl-row { grid-template-columns: 1fr 110px; }
  .meta { grid-template-columns: 1fr; }
}
@media (max-width: 460px) {
  .people-grid, .people-grid.compact { grid-template-columns: 1fr 1fr; }
  .topics { grid-template-columns: 1fr; }
}