:root {
  color-scheme: light;
  --bg: #eef6ff;
  --bg-soft: #f8fbff;
  --surface: #ffffff;
  --surface-strong: #eff6ff;
  --text: #0f172a;
  --muted: #475569;
  --brand: #1d4ed8;
  --brand-strong: #1e3a8a;
  --brand-soft: #dbeafe;
  --gold: #f59e0b;
  --line: rgba(30, 64, 175, 0.14);
  --shadow: 0 24px 70px rgba(15, 23, 42, 0.13);
  --radius-lg: 28px;
  --radius-md: 20px;
  --max: 1180px;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  min-width: 320px;
  background:
    radial-gradient(circle at top left, rgba(37, 99, 235, 0.22), transparent 36rem),
    linear-gradient(180deg, #eef6ff 0%, #f8fbff 40%, #ffffff 100%);
  color: var(--text);
  font-family:
    Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI",
    sans-serif;
  line-height: 1.6;
}

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

a {
  color: inherit;
}

.skip-link {
  position: fixed;
  left: 1rem;
  top: 1rem;
  z-index: 1000;
  transform: translateY(-180%);
  border-radius: 999px;
  background: var(--surface);
  padding: 0.75rem 1rem;
  color: var(--brand);
  font-weight: 700;
  box-shadow: var(--shadow);
}

.skip-link:focus {
  transform: translateY(0);
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  width: min(calc(100% - 2rem), var(--max));
  margin: 1rem auto 0;
  padding: 0.75rem 0.85rem;
  border: 1px solid rgba(255, 255, 255, 0.7);
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.86);
  box-shadow: 0 14px 45px rgba(15, 23, 42, 0.09);
  backdrop-filter: blur(18px);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 0.7rem;
  text-decoration: none;
  font-weight: 800;
  color: var(--brand-strong);
  letter-spacing: -0.02em;
}

.brand img {
  width: 42px;
  height: 42px;
  object-fit: contain;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 0.25rem;
}

.nav-links a {
  border-radius: 999px;
  padding: 0.65rem 0.9rem;
  color: #334155;
  font-size: 0.95rem;
  font-weight: 700;
  text-decoration: none;
}

.nav-links a:hover,
.nav-links a:focus-visible {
  background: var(--brand-soft);
  color: var(--brand-strong);
  outline: none;
}

.section-shell {
  width: min(calc(100% - 2rem), var(--max));
  margin: 0 auto;
  padding: 5.5rem 0;
}

.hero {
  display: grid;
  grid-template-columns: minmax(0, 1.02fr) minmax(320px, 0.78fr);
  align-items: center;
  gap: clamp(2rem, 6vw, 5rem);
  min-height: calc(100svh - 6rem);
  padding-top: 5rem;
}

.eyebrow {
  margin: 0 0 0.8rem;
  color: var(--brand);
  font-size: 0.82rem;
  font-weight: 900;
  letter-spacing: 0.14em;
  text-transform: uppercase;
}

h1,
h2,
h3,
p {
  margin-top: 0;
}

h1 {
  max-width: 780px;
  margin-bottom: 1.2rem;
  font-size: clamp(2.65rem, 7vw, 5.8rem);
  line-height: 0.96;
  letter-spacing: -0.075em;
}

h2 {
  margin-bottom: 1rem;
  font-size: clamp(2rem, 4.6vw, 3.65rem);
  line-height: 1.02;
  letter-spacing: -0.055em;
}

h3 {
  margin-bottom: 0.55rem;
  font-size: 1.25rem;
  line-height: 1.2;
  letter-spacing: -0.025em;
}

.hero-subtitle {
  max-width: 660px;
  color: var(--muted);
  font-size: clamp(1.05rem, 2vw, 1.35rem);
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.85rem;
  margin-top: 2rem;
}

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 48px;
  border-radius: 999px;
  padding: 0.85rem 1.3rem;
  font-weight: 850;
  text-decoration: none;
  transition: transform 180ms ease, box-shadow 180ms ease, background 180ms ease;
}

.button:hover,
.button:focus-visible {
  transform: translateY(-2px);
  outline: none;
}

.button-primary {
  background: linear-gradient(135deg, var(--brand), var(--brand-strong));
  color: #fff;
  box-shadow: 0 18px 35px rgba(29, 78, 216, 0.26);
}

.button-secondary {
  border: 1px solid var(--line);
  background: rgba(255, 255, 255, 0.74);
  color: var(--brand-strong);
}

.button-light {
  background: #fff;
  color: var(--brand-strong);
  box-shadow: 0 18px 35px rgba(15, 23, 42, 0.18);
}

.hero-card {
  position: relative;
  overflow: hidden;
  border: 1px solid rgba(255, 255, 255, 0.75);
  border-radius: var(--radius-lg);
  background:
    linear-gradient(135deg, rgba(29, 78, 216, 0.96), rgba(30, 64, 175, 0.88)),
    radial-gradient(circle at top right, rgba(245, 158, 11, 0.8), transparent 17rem);
  color: #fff;
  box-shadow: var(--shadow);
}

.hero-card::before {
  content: "";
  position: absolute;
  inset: -22% auto auto -18%;
  width: 18rem;
  height: 18rem;
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.16);
}

.chess-board {
  position: relative;
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  padding: clamp(1rem, 3vw, 2rem);
  gap: 0.7rem;
}

.chess-board span {
  display: grid;
  aspect-ratio: 1;
  place-items: center;
  border-radius: 18px;
  background: rgba(255, 255, 255, 0.14);
  font-size: clamp(2.1rem, 5vw, 4rem);
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.18);
}

.chess-board span:nth-child(2n) {
  background: rgba(255, 255, 255, 0.28);
}

.hero-stats {
  position: relative;
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1px;
  background: rgba(255, 255, 255, 0.2);
}

.hero-stats div {
  padding: 1.1rem;
  background: rgba(15, 23, 42, 0.18);
}

.hero-stats strong,
.hero-stats span {
  display: block;
}

.hero-stats strong {
  font-size: clamp(1.4rem, 3vw, 2rem);
  line-height: 1;
}

.hero-stats span {
  margin-top: 0.35rem;
  color: rgba(255, 255, 255, 0.82);
  font-size: 0.86rem;
}

.split-section {
  display: grid;
  grid-template-columns: 0.8fr 1fr;
  gap: clamp(2rem, 6vw, 5rem);
  align-items: start;
}

.text-stack {
  color: var(--muted);
  font-size: 1.08rem;
}

.text-stack p:last-child {
  margin-bottom: 0;
}

.section-heading {
  max-width: 780px;
  margin: 0 auto 2.2rem;
  text-align: center;
}

.card-grid {
  display: grid;
  gap: 1rem;
}

.four-cols {
  grid-template-columns: repeat(4, 1fr);
}

.three-cols {
  grid-template-columns: repeat(3, 1fr);
}

.info-card,
.activity-card,
.highlight-card {
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  background: rgba(255, 255, 255, 0.78);
  box-shadow: 0 16px 38px rgba(15, 23, 42, 0.08);
}

.info-card,
.activity-card {
  padding: 1.4rem;
}

.info-card p,
.activity-card p,
.highlight-card p,
.cta-section p,
.site-footer {
  color: var(--muted);
}

.card-icon {
  display: grid;
  width: 3rem;
  height: 3rem;
  margin-bottom: 1rem;
  place-items: center;
  border-radius: 16px;
  background: var(--brand-soft);
  color: var(--brand-strong);
  font-size: 1.6rem;
}

.highlight-section {
  padding-top: 2rem;
  padding-bottom: 2rem;
}

.highlight-card {
  overflow: hidden;
  padding: clamp(1.5rem, 4vw, 3.2rem);
  background:
    radial-gradient(circle at 95% 10%, rgba(245, 158, 11, 0.18), transparent 20rem),
    linear-gradient(135deg, #fff, #eff6ff);
}

.highlight-card p:last-child {
  max-width: 850px;
  margin-bottom: 0;
  font-size: 1.08rem;
}

.audience-section {
  padding-top: 2rem;
}

.pill-list {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 0.8rem;
}

.pill-list span {
  border: 1px solid var(--line);
  border-radius: 999px;
  background: #fff;
  padding: 0.85rem 1.05rem;
  color: var(--brand-strong);
  font-weight: 800;
  box-shadow: 0 10px 24px rgba(15, 23, 42, 0.07);
}

.cta-section {
  display: grid;
  grid-template-columns: auto 1fr auto;
  align-items: center;
  gap: clamp(1.2rem, 4vw, 2.5rem);
  margin-bottom: 4rem;
  padding: clamp(1.4rem, 4vw, 2.6rem);
  border-radius: var(--radius-lg);
  background: linear-gradient(135deg, var(--brand), var(--brand-strong));
  color: #fff;
  box-shadow: var(--shadow);
}

.cta-section img {
  width: 86px;
  opacity: 0.94;
}

.cta-section .eyebrow,
.cta-section p {
  color: rgba(255, 255, 255, 0.78);
}

.cta-section h2 {
  margin-bottom: 0.7rem;
  font-size: clamp(1.75rem, 3.2vw, 2.65rem);
}

.cta-section p:last-child {
  margin-bottom: 0;
}

.site-footer {
  width: min(calc(100% - 2rem), var(--max));
  margin: 0 auto;
  padding: 1.5rem 0 2rem;
  border-top: 1px solid var(--line);
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 0.75rem;
  font-size: 0.95rem;
}

.site-footer p {
  margin-bottom: 0;
}

.site-footer a {
  color: var(--brand);
  font-weight: 800;
  text-decoration: none;
}

@media (max-width: 900px) {
  .site-header {
    align-items: flex-start;
    border-radius: 24px;
    flex-direction: column;
  }

  .nav-links {
    width: 100%;
    overflow-x: auto;
    padding-bottom: 0.15rem;
  }

  .hero,
  .split-section,
  .cta-section {
    grid-template-columns: 1fr;
  }

  .hero {
    min-height: auto;
  }

  .four-cols,
  .three-cols {
    grid-template-columns: repeat(2, 1fr);
  }

  .cta-section {
    text-align: left;
  }
}

@media (max-width: 620px) {
  .section-shell {
    width: min(calc(100% - 1rem), var(--max));
    padding: 4rem 0;
  }

  .site-header {
    width: min(calc(100% - 1rem), var(--max));
  }

  .brand span {
    font-size: 0.95rem;
  }

  .nav-links a {
    padding: 0.58rem 0.72rem;
    font-size: 0.9rem;
    white-space: nowrap;
  }

  h1 {
    font-size: clamp(2.45rem, 15vw, 4rem);
  }

  .hero-actions {
    flex-direction: column;
  }

  .button {
    width: 100%;
  }

  .four-cols,
  .three-cols,
  .hero-stats {
    grid-template-columns: 1fr;
  }

  .chess-board {
    grid-template-columns: repeat(3, 1fr);
  }

  .site-footer {
    width: min(calc(100% - 1rem), var(--max));
  }
}