:root {
  --sky: #e0f2fe;
  --sky-deep: #bfdbfe;
  --ink: #0f172a;
  --muted: #516075;
  --green: #34d399;
  --green-deep: #047857;
  --pink: #f472b6;
  --yellow: #fde68a;
  --brown: #92400e;
  --paper: #fffdf8;
  --line: rgba(15, 23, 42, 0.12);
  --shadow: 0 26px 80px rgba(39, 78, 101, 0.14);
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: "Avenir Next", Avenir, Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  text-rendering: geometricPrecision;
}

body::before {
  position: fixed;
  inset: 0;
  z-index: -1;
  pointer-events: none;
  content: "";
  background:
    radial-gradient(circle at 88% 8%, rgba(253, 230, 138, 0.75), transparent 16rem),
    radial-gradient(circle at 8% 22%, rgba(224, 242, 254, 0.9), transparent 27rem);
}

a {
  color: inherit;
  text-decoration: none;
}

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

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

p {
  color: var(--muted);
  line-height: 1.68;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  display: flex;
  min-height: 76px;
  align-items: center;
  justify-content: space-between;
  gap: 1.5rem;
  padding: 0 5vw;
  border-bottom: 1px solid var(--line);
  background: rgba(255, 253, 248, 0.88);
  backdrop-filter: blur(18px);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 0.75rem;
  font-size: 1.12rem;
  font-weight: 900;
}

.brand img {
  width: 48px;
  height: 48px;
  border-radius: 13px;
  object-fit: cover;
}

.site-header nav,
footer nav {
  display: flex;
  flex-wrap: wrap;
  gap: 1.25rem;
  color: var(--muted);
  font-weight: 700;
}

.site-header nav a:hover,
footer nav a:hover {
  color: var(--ink);
}

.header-cta,
.primary-button,
.secondary-button {
  display: inline-flex;
  min-height: 48px;
  align-items: center;
  justify-content: center;
  padding: 0 1.15rem;
  border: 1px solid var(--line);
  border-radius: 999px;
  font-weight: 900;
  transition: transform 160ms ease, box-shadow 160ms ease;
}

.header-cta,
.primary-button {
  border-color: transparent;
  background: var(--ink);
  color: #fff;
}

.secondary-button {
  background: rgba(255, 255, 255, 0.7);
}

.header-cta:hover,
.primary-button:hover,
.secondary-button:hover {
  transform: translateY(-2px);
  box-shadow: 0 12px 28px rgba(15, 23, 42, 0.12);
}

.section-shell {
  width: min(1160px, 90vw);
  margin: 0 auto;
  padding: 6rem 0;
}

.hero {
  display: grid;
  min-height: 720px;
  grid-template-columns: minmax(0, 1.05fr) minmax(360px, 0.85fr);
  gap: 4rem;
  align-items: center;
  padding-top: 3.5rem;
}

.eyebrow {
  margin-bottom: 1rem;
  color: var(--green-deep);
  font-size: 0.78rem;
  font-weight: 900;
  letter-spacing: 0.16em;
  text-transform: uppercase;
}

h1 {
  max-width: 760px;
  margin-bottom: 1.5rem;
  font-size: clamp(3.35rem, 7vw, 5.8rem);
  line-height: 0.96;
  letter-spacing: -0.055em;
}

h2 {
  margin-bottom: 1.1rem;
  font-size: clamp(2.35rem, 5vw, 4rem);
  line-height: 1;
  letter-spacing: -0.045em;
}

h3 {
  margin-bottom: 0.65rem;
  font-size: 1.15rem;
}

.lede {
  max-width: 680px;
  font-size: 1.2rem;
}

.actions,
.signals {
  display: flex;
  flex-wrap: wrap;
  gap: 0.8rem;
  margin-top: 2rem;
}

.signals span {
  padding: 0.65rem 0.8rem;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.66);
  color: var(--muted);
  font-size: 0.82rem;
  font-weight: 800;
}

.hero-world {
  position: relative;
  min-height: 560px;
  border: 1px solid rgba(15, 23, 42, 0.08);
  border-radius: 42px;
  background:
    radial-gradient(circle at 75% 17%, var(--yellow) 0 54px, transparent 55px),
    linear-gradient(180deg, var(--sky) 0 62%, #d1fae5 62% 100%);
  box-shadow: var(--shadow);
  overflow: hidden;
}

.hero-world::before {
  position: absolute;
  right: -9%;
  bottom: -24%;
  width: 76%;
  height: 78%;
  border-radius: 50% 50% 12% 12%;
  background:
    radial-gradient(circle at 42% 20%, #6ee7b7 0 25%, transparent 26%),
    radial-gradient(circle at 67% 28%, #34d399 0 31%, transparent 32%),
    linear-gradient(90deg, transparent 42%, var(--brown) 43% 58%, transparent 59%);
  content: "";
}

.hero-world::after {
  position: absolute;
  inset: 12% 10%;
  border: 2px dashed rgba(15, 23, 42, 0.13);
  border-radius: 50%;
  content: "";
}

.hero-logo {
  position: absolute;
  z-index: 2;
  inset: 50% auto auto 50%;
  width: 235px;
  border: 5px solid rgba(255, 255, 255, 0.88);
  border-radius: 28px;
  box-shadow: 0 18px 50px rgba(15, 23, 42, 0.16);
  transform: translate(-50%, -50%);
}

.world-chip {
  position: absolute;
  z-index: 3;
  display: flex;
  width: 138px;
  align-items: center;
  gap: 0.6rem;
  padding: 0.55rem;
  border: 1px solid rgba(15, 23, 42, 0.09);
  border-radius: 18px;
  background: rgba(255, 255, 255, 0.9);
  box-shadow: 0 14px 36px rgba(15, 23, 42, 0.12);
  color: var(--ink);
  font-size: 0.8rem;
  font-weight: 900;
}

.world-chip img {
  width: 46px;
  height: 46px;
  border-radius: 12px;
  object-fit: cover;
}

.chip-math { top: 11%; left: 7%; }
.chip-science { top: 16%; right: 5%; }
.chip-language { bottom: 11%; left: 7%; }
.chip-story { right: 5%; bottom: 15%; }

.proof-strip {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
  background: #fff;
}

.proof-strip div {
  padding: 1.5rem 5vw;
  border-right: 1px solid var(--line);
}

.proof-strip div:last-child {
  border-right: 0;
}

.proof-strip strong {
  display: block;
  margin-bottom: 0.35rem;
}

.proof-strip span {
  color: var(--muted);
  line-height: 1.5;
}

.section-heading {
  max-width: 790px;
}

.today-flow {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 1rem;
  margin-top: 3rem;
}

article {
  padding: 1.4rem;
  border: 1px solid var(--line);
  border-radius: 24px;
  background: rgba(255, 255, 255, 0.72);
}

article p {
  margin-bottom: 0;
}

.today-flow article {
  position: relative;
  min-height: 215px;
  padding-top: 4rem;
}

.today-flow article::after {
  position: absolute;
  top: 2rem;
  right: -1.05rem;
  width: 1.1rem;
  height: 2px;
  background: var(--green);
  content: "";
}

.today-flow article:last-child::after {
  display: none;
}

.today-flow span {
  position: absolute;
  top: 1.2rem;
  left: 1.4rem;
  color: var(--green-deep);
  font-size: 0.78rem;
  font-weight: 900;
  letter-spacing: 0.12em;
}

.worlds-section {
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
  background:
    linear-gradient(rgba(255, 255, 255, 0.56), rgba(255, 255, 255, 0.56)),
    var(--sky);
}

.world-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 1rem;
  margin-top: 3rem;
}

.world-grid article {
  min-height: 315px;
  background: rgba(255, 255, 255, 0.84);
}

.world-grid img {
  width: 100%;
  max-height: 175px;
  margin-bottom: 1.2rem;
  border-radius: 18px;
  object-fit: cover;
  object-position: center;
}

.parent-section {
  display: grid;
  grid-template-columns: minmax(0, 0.78fr) minmax(0, 1.22fr);
  gap: 4rem;
  align-items: start;
}

.principle-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1rem;
}

.preview-section {
  padding: 1rem 0 6rem;
}

.preview-card {
  display: grid;
  width: min(1160px, 90vw);
  margin: 0 auto;
  grid-template-columns: minmax(0, 1.2fr) minmax(280px, 0.8fr);
  gap: 3rem;
  align-items: center;
  padding: 3rem;
  border-radius: 34px;
  background: var(--ink);
  color: #fff;
  box-shadow: var(--shadow);
}

.preview-card p {
  color: #cbd5e1;
}

.preview-card .eyebrow {
  color: #6ee7b7;
}

.preview-card .primary-button {
  background: var(--green);
  color: var(--ink);
}

.preview-card .secondary-button {
  border-color: rgba(255, 255, 255, 0.22);
  background: rgba(255, 255, 255, 0.08);
  color: #fff;
}

footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 2rem;
  padding: 2rem 5vw;
  border-top: 1px solid var(--line);
  color: var(--muted);
}

footer strong,
footer span {
  display: block;
}

footer strong {
  margin-bottom: 0.25rem;
  color: var(--ink);
}

@media (max-width: 960px) {
  .site-header nav {
    display: none;
  }

  .hero,
  .parent-section,
  .preview-card {
    grid-template-columns: 1fr;
  }

  .hero {
    min-height: auto;
  }

  .today-flow,
  .world-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .today-flow article::after {
    display: none;
  }
}

@media (max-width: 680px) {
  .header-cta {
    display: none;
  }

  .section-shell {
    padding: 4.5rem 0;
  }

  .hero {
    gap: 2.5rem;
    padding-top: 3rem;
  }

  .hero-world {
    min-height: 480px;
  }

  .proof-strip,
  .today-flow,
  .world-grid,
  .principle-grid {
    grid-template-columns: 1fr;
  }

  .proof-strip div {
    border-right: 0;
    border-bottom: 1px solid var(--line);
  }

  .world-chip {
    width: 118px;
  }

  .preview-card {
    padding: 2rem;
  }

  footer {
    align-items: flex-start;
    flex-direction: column;
  }
}