:root {
  color-scheme: light dark;
  --ink: #17213b;
  --muted: #65708a;
  --paper: #faf7ef;
  --paper-strong: #fffdf8;
  --brand: #3159d9;
  --brand-dark: #182a66;
  --accent: #f2a43a;
  --line: rgba(23, 33, 59, 0.12);
  --shadow: 0 24px 70px rgba(24, 42, 102, 0.13);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  font-synthesis: none;
}

* {
  box-sizing: border-box;
}

html {
  background: var(--paper);
  scroll-behavior: smooth;
}

body {
  min-height: 100vh;
  margin: 0;
  color: var(--ink);
  background:
    radial-gradient(circle at 8% 0%, rgba(242, 164, 58, 0.17), transparent 30rem),
    radial-gradient(circle at 95% 22%, rgba(49, 89, 217, 0.15), transparent 32rem),
    var(--paper);
}

a {
  color: var(--brand);
  text-underline-offset: 0.16em;
}

a:hover {
  text-decoration-thickness: 0.12em;
}

a:focus-visible,
button:focus-visible {
  outline: 3px solid var(--accent);
  outline-offset: 4px;
}

.site-header,
.site-footer,
.page,
.hero {
  width: min(1120px, calc(100% - 40px));
  margin-inline: auto;
}

.site-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  padding-block: 24px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  color: var(--ink);
  font-size: 1.15rem;
  font-weight: 780;
  letter-spacing: -0.02em;
  text-decoration: none;
}

.brand img {
  width: 42px;
  height: 42px;
  border-radius: 11px;
  box-shadow: 0 9px 22px rgba(49, 89, 217, 0.24);
}

.site-nav {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 18px;
  color: var(--muted);
  font-size: 0.92rem;
  font-weight: 650;
}

.site-nav a {
  color: inherit;
  text-decoration: none;
}

.language-switcher {
  display: inline-flex;
  padding: 3px;
  gap: 1px;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: color-mix(in srgb, var(--paper-strong) 85%, transparent);
}

.language-switcher button {
  min-width: 37px;
  min-height: 32px;
  padding: 5px 8px;
  border: 0;
  border-radius: 999px;
  color: var(--muted);
  background: transparent;
  font: inherit;
  font-size: 0.78rem;
  font-weight: 720;
  cursor: pointer;
}

.language-switcher button[aria-pressed="true"] {
  color: white;
  background: var(--brand);
}

.hero {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(340px, 0.78fr);
  align-items: center;
  gap: clamp(48px, 8vw, 104px);
  min-height: calc(100vh - 108px);
  padding-block: 72px 112px;
}

.eyebrow {
  margin: 0 0 16px;
  color: var(--brand);
  font-size: 0.78rem;
  font-weight: 800;
  letter-spacing: 0.15em;
  text-transform: uppercase;
}

h1,
h2,
h3,
p {
  text-wrap: pretty;
}

h1 {
  max-width: 12ch;
  margin: 0;
  font-size: clamp(3.4rem, 8vw, 6.8rem);
  line-height: 0.93;
  letter-spacing: -0.07em;
}

.lede {
  max-width: 38rem;
  margin: 28px 0 0;
  color: var(--muted);
  font-size: clamp(1.08rem, 2vw, 1.32rem);
  line-height: 1.65;
}

.hero-actions {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 14px;
  margin-top: 34px;
}

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 50px;
  padding: 13px 21px;
  border: 0;
  border-radius: 15px;
  color: white;
  background: var(--brand);
  box-shadow: 0 12px 30px rgba(49, 89, 217, 0.24);
  font: inherit;
  font-weight: 760;
  text-decoration: none;
  cursor: pointer;
}

.button.secondary {
  color: var(--ink);
  background: var(--paper-strong);
  box-shadow: inset 0 0 0 1px var(--line);
}

.button[aria-disabled="true"] {
  color: var(--muted);
  background: rgba(101, 112, 138, 0.12);
  box-shadow: none;
  cursor: not-allowed;
}

.board-shell {
  position: relative;
  width: min(100%, 470px);
  aspect-ratio: 0.86;
  margin-inline: auto;
  padding: clamp(24px, 5vw, 42px);
  border-radius: 48px;
  background: var(--brand-dark);
  box-shadow: var(--shadow);
  transform: rotate(2.5deg);
}

.board-shell::before {
  content: "";
  position: absolute;
  inset: 12px;
  border: 1px solid rgba(255, 255, 255, 0.1);
  border-radius: 38px;
}

.board-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: clamp(10px, 2.2vw, 16px);
  position: relative;
  height: 100%;
}

.tile {
  display: grid;
  place-items: center;
  aspect-ratio: 1;
  border-radius: 20px;
  color: var(--brand-dark);
  background: #fff8e8;
  box-shadow: inset 0 -4px 0 rgba(24, 42, 102, 0.08);
  font-size: clamp(1.1rem, 3.8vw, 2rem);
  font-weight: 850;
}

.tile.accent {
  color: #4b2a00;
  background: var(--accent);
}

.tile.empty {
  background: rgba(255, 255, 255, 0.04);
  box-shadow: inset 0 0 0 1px rgba(255, 255, 255, 0.08);
}

.feature-strip {
  grid-column: 1 / -1;
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1px;
  overflow: hidden;
  margin-top: 22px;
  border: 1px solid var(--line);
  border-radius: 24px;
  background: var(--line);
}

.feature-strip > div {
  min-height: 150px;
  padding: 26px;
  background: color-mix(in srgb, var(--paper-strong) 93%, transparent);
}

.feature-strip strong {
  display: block;
  margin-bottom: 8px;
  font-size: 1.05rem;
}

.feature-strip p {
  margin: 0;
  color: var(--muted);
  line-height: 1.55;
}

.page {
  max-width: 840px;
  padding-block: 76px 120px;
}

.page-header {
  margin-bottom: 58px;
}

.page h1 {
  max-width: none;
  font-size: clamp(3rem, 7vw, 5.7rem);
}

.page h2 {
  margin: 48px 0 12px;
  font-size: 1.45rem;
  letter-spacing: -0.025em;
}

.page h3 {
  margin: 28px 0 10px;
}

.page p,
.page li {
  color: var(--muted);
  font-size: 1.04rem;
  line-height: 1.72;
}

.page ul,
.page ol {
  padding-left: 1.25rem;
}

.notice,
.challenge-card {
  padding: 28px;
  border: 1px solid var(--line);
  border-radius: 24px;
  background: color-mix(in srgb, var(--paper-strong) 92%, transparent);
  box-shadow: 0 16px 40px rgba(24, 42, 102, 0.06);
}

.notice strong {
  color: var(--ink);
}

.challenge-wrap {
  display: grid;
  place-items: center;
  min-height: calc(100vh - 110px);
  padding-block: 64px 100px;
}

.challenge-card {
  width: min(620px, 100%);
  padding: clamp(30px, 7vw, 58px);
  text-align: center;
}

.challenge-card .brand-mark {
  width: 86px;
  height: 86px;
  border-radius: 23px;
  box-shadow: 0 16px 34px rgba(49, 89, 217, 0.22);
}

.challenge-card h1 {
  max-width: none;
  margin-top: 28px;
  font-size: clamp(2.5rem, 8vw, 4.4rem);
}

.challenge-status {
  min-height: 1.7em;
  margin: 12px 0 24px;
  color: var(--muted);
  line-height: 1.6;
}

.privacy-note {
  margin-top: 28px;
  color: var(--muted);
  font-size: 0.88rem;
  line-height: 1.55;
}

.site-footer {
  display: flex;
  justify-content: space-between;
  gap: 24px;
  padding-block: 30px 42px;
  border-top: 1px solid var(--line);
  color: var(--muted);
  font-size: 0.86rem;
}

.site-footer nav {
  display: flex;
  flex-wrap: wrap;
  gap: 18px;
}

[hidden] {
  display: none !important;
}

@media (max-width: 760px) {
  .site-header {
    align-items: flex-start;
    flex-wrap: wrap;
  }

  .site-nav {
    order: 3;
    width: 100%;
  }

  .hero {
    grid-template-columns: 1fr;
    min-height: auto;
    padding-block: 48px 82px;
  }

  .hero-copy {
    order: 1;
  }

  .board-shell {
    order: 2;
    width: min(92%, 430px);
  }

  .feature-strip {
    grid-template-columns: 1fr;
  }

  .site-footer {
    flex-direction: column;
  }
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }
}

@media (prefers-contrast: more) {
  :root {
    --muted: #404a62;
    --line: rgba(23, 33, 59, 0.35);
  }
}

@media (prefers-color-scheme: dark) {
  :root {
    --ink: #f7f2e5;
    --muted: #b9c0d1;
    --paper: #11172a;
    --paper-strong: #192138;
    --brand: #7292ff;
    --brand-dark: #0b1020;
    --line: rgba(255, 255, 255, 0.13);
    --shadow: 0 28px 80px rgba(0, 0, 0, 0.34);
  }

  .language-switcher button[aria-pressed="true"] {
    color: #10172a;
  }
}