:root {
  --bg: #0c0d11;
  --bg-raised: #12141a;
  --surface: #1a1d24;
  --surface-hi: #242832;
  --line: #2c313c;
  --ink: #f5f6f8;
  --muted: #8e93a3;
  --faint: #5c6170;
  --lime: #d4ff3a;
  --lime-lip: #8dae12;
  --on-lime: #15170c;
  --rival: #ff4f8b;
  --sky: #3fc8ff;
  --violet: #8c7cff;
  --radius: 18px;
  --max: 1120px;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: 'Nunito', system-ui, -apple-system, 'Segoe UI', sans-serif;
  font-size: 17px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  background-image:
    linear-gradient(var(--bg-raised) 1px, transparent 1px),
    linear-gradient(90deg, var(--bg-raised) 1px, transparent 1px);
  background-size: 44px 44px;
}
img { max-width: 100%; display: block; }
a { color: inherit; }

.wrap { max-width: var(--max); margin: 0 auto; padding: 0 20px; }
.display {
  font-family: 'Anton', Impact, 'Arial Narrow', sans-serif;
  font-weight: 400;
  text-transform: uppercase;
  letter-spacing: 0.01em;
  line-height: 0.95;
  margin: 0;
}
.lime { color: var(--lime); }
.kicker {
  font-size: 12px;
  font-weight: 900;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--muted);
}
.muted { color: var(--muted); }

/* ---------- nav ---------- */
.nav {
  position: sticky;
  top: 0;
  z-index: 10;
  background: rgba(12, 13, 17, 0.86);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--line);
}
.nav .wrap {
  display: flex;
  align-items: center;
  gap: 24px;
  height: 64px;
}
.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  text-decoration: none;
}
.brand img { width: 34px; height: 34px; border-radius: 9px; }
.brand span { font-family: 'Anton', sans-serif; font-size: 24px; letter-spacing: 0.04em; }
.nav-links { display: flex; gap: 22px; margin-left: auto; }
.nav-links a {
  text-decoration: none;
  font-weight: 800;
  font-size: 14px;
  color: var(--muted);
}
.nav-links a:hover { color: var(--ink); }

/* ---------- buttons ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 14px 24px;
  border-radius: 14px;
  font-weight: 900;
  font-size: 15px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  text-decoration: none;
  border: 0;
  cursor: pointer;
  transition: transform 0.12s ease, box-shadow 0.12s ease;
}
.btn-lime {
  background: var(--lime);
  color: var(--on-lime);
  box-shadow: 0 5px 0 var(--lime-lip);
}
.btn-lime:hover { transform: translateY(-1px); }
.btn-lime:active { transform: translateY(4px); box-shadow: 0 1px 0 var(--lime-lip); }
.btn-ghost {
  background: var(--surface);
  color: var(--ink);
  border: 1px solid var(--line);
  box-shadow: 0 5px 0 #07080b;
}
.btn-sm { padding: 10px 16px; font-size: 13px; }
.btn svg { width: 20px; height: 20px; }

/* ---------- hero ---------- */
.hero { padding: 72px 0 56px; position: relative; overflow: hidden; }
.hero::before {
  content: '';
  position: absolute;
  inset: -20% -10% auto auto;
  width: 640px;
  height: 640px;
  background: radial-gradient(circle, rgba(212, 255, 58, 0.14), transparent 60%);
  pointer-events: none;
}
.hero .wrap {
  display: grid;
  grid-template-columns: 1.05fr 0.95fr;
  gap: 40px;
  align-items: center;
}
.chips { display: flex; gap: 8px; flex-wrap: wrap; margin-bottom: 18px; }
.chip {
  padding: 5px 10px;
  border-radius: 8px;
  background: var(--surface);
  border: 1px solid var(--line);
  font-size: 12px;
  font-weight: 900;
  letter-spacing: 0.12em;
  text-transform: uppercase;
}
.chip.on { background: var(--lime); color: var(--on-lime); border-color: var(--lime); }
.hero h1 { font-size: clamp(56px, 9vw, 116px); }
.hero p.lead { font-size: 20px; color: var(--muted); max-width: 520px; margin: 22px 0 30px; }
.cta-row { display: flex; gap: 14px; flex-wrap: wrap; align-items: center; }
.note { font-size: 13px; color: var(--faint); margin-top: 14px; }

.phones { position: relative; height: 600px; }
.phone {
  position: absolute;
  width: 260px;
  aspect-ratio: 9 / 19;
  border-radius: 34px;
  padding: 8px;
  background: #1c1b22;
  border: 1px solid var(--line);
  box-shadow: 0 30px 60px rgba(0, 0, 0, 0.55);
  overflow: hidden;
}
.phone img { width: 100%; height: 100%; object-fit: cover; object-position: top; border-radius: 27px; }
.phones .p1 { left: 6%; top: 40px; transform: rotate(-6deg); }
.phones .p2 { right: 2%; top: 0; transform: rotate(5deg); }

/* ---------- stats strip ---------- */
.strip {
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
  background: var(--bg-raised);
}
.strip .wrap {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  text-align: center;
}
.strip div.stat { padding: 28px 10px; }
.strip div.stat + div.stat { border-left: 1px solid var(--line); }
.stat b { display: block; font-family: 'Anton', sans-serif; font-weight: 400; font-size: 44px; line-height: 1; }
.stat span { font-size: 13px; font-weight: 800; letter-spacing: 0.12em; text-transform: uppercase; color: var(--muted); }

/* ---------- sections ---------- */
section.block { padding: 96px 0; }
.head { max-width: 640px; margin-bottom: 44px; }
.head h2 { font-size: clamp(40px, 6vw, 68px); margin-top: 10px; }
.head p { color: var(--muted); font-size: 18px; margin: 16px 0 0; }

.split {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 48px;
  align-items: center;
}
.split.rev > :first-child { order: 2; }
.duo { display: flex; gap: 18px; justify-content: center; }
.duo .phone { position: relative; width: 240px; }
.duo .phone:nth-child(2) { margin-top: 48px; }

.cards { display: grid; gap: 14px; }
.cards.two { grid-template-columns: repeat(2, 1fr); }
.cards.four { grid-template-columns: repeat(4, 1fr); }
.card {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 22px;
}
.card h3 {
  font-family: 'Anton', sans-serif;
  font-weight: 400;
  text-transform: uppercase;
  font-size: 24px;
  letter-spacing: 0.02em;
  margin: 0 0 6px;
}
.card p { margin: 0; color: var(--muted); font-size: 15px; }
.card .tag {
  display: inline-block;
  margin-bottom: 12px;
  font-size: 11px;
  font-weight: 900;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  padding: 4px 8px;
  border-radius: 6px;
  background: var(--surface-hi);
  color: var(--muted);
}
.card .tag.on { background: var(--lime); color: var(--on-lime); }

.games { display: grid; grid-template-columns: repeat(4, 1fr); gap: 14px; }
.game {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 18px;
}
.game .dot { width: 10px; height: 10px; border-radius: 50%; margin-bottom: 14px; }
.game h4 { margin: 0; font-size: 18px; font-weight: 900; }
.game p { margin: 4px 0 0; color: var(--muted); font-size: 14px; }
.game small { display: block; margin-top: 12px; font-weight: 800; color: var(--faint); font-size: 12px; letter-spacing: 0.1em; text-transform: uppercase; }

.gallery { display: flex; gap: 18px; overflow-x: auto; padding: 6px 2px 18px; scroll-snap-type: x mandatory; }
.gallery .phone { position: relative; flex: 0 0 220px; scroll-snap-align: start; }

.list { list-style: none; padding: 0; margin: 22px 0 0; display: grid; gap: 12px; }
.list li { display: flex; gap: 12px; align-items: flex-start; color: var(--muted); }
.list li::before {
  content: '';
  flex: 0 0 8px;
  height: 8px;
  margin-top: 9px;
  border-radius: 2px;
  background: var(--lime);
}
.list b { color: var(--ink); }

/* ---------- FAQ ---------- */
.faq { display: grid; gap: 10px; max-width: 820px; }
.faq details {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 14px;
  padding: 0 20px;
}
.faq summary {
  cursor: pointer;
  list-style: none;
  padding: 18px 0;
  font-weight: 900;
  display: flex;
  justify-content: space-between;
  gap: 16px;
}
.faq summary::-webkit-details-marker { display: none; }
.faq summary::after { content: '+'; color: var(--lime); font-size: 22px; line-height: 1; }
.faq details[open] summary::after { content: '–'; }
.faq details p { margin: 0 0 18px; color: var(--muted); }

/* ---------- final CTA ---------- */
.final {
  text-align: center;
  padding: 100px 0;
  border-top: 1px solid var(--line);
  background: radial-gradient(ellipse at center top, rgba(212, 255, 58, 0.1), transparent 60%);
}
.final h2 { font-size: clamp(48px, 8vw, 96px); }
.final p { color: var(--muted); font-size: 18px; margin: 18px auto 30px; max-width: 520px; }

/* ---------- footer ---------- */
footer {
  border-top: 1px solid var(--line);
  padding: 36px 0 48px;
  color: var(--muted);
  font-size: 14px;
}
footer .wrap { display: flex; flex-wrap: wrap; gap: 20px 32px; align-items: center; }
footer nav { display: flex; gap: 22px; flex-wrap: wrap; margin-left: auto; }
footer a { text-decoration: none; font-weight: 800; }
footer a:hover { color: var(--ink); }

/* ---------- legal pages ---------- */
.legal { padding: 64px 0 96px; }
.legal .wrap { max-width: 780px; }
.legal h1 { font-size: clamp(44px, 7vw, 72px); margin-bottom: 8px; }
.legal h2 { font-family: 'Anton', sans-serif; font-weight: 400; text-transform: uppercase; font-size: 26px; letter-spacing: 0.02em; margin: 44px 0 10px; }
.legal h3 { font-size: 17px; margin: 22px 0 6px; }
.legal p, .legal li { color: #c9ccd6; }
.legal ul { padding-left: 20px; }
.legal li { margin: 6px 0; }
.legal table { width: 100%; border-collapse: collapse; margin: 14px 0; font-size: 15px; }
.legal th, .legal td { text-align: left; padding: 10px 12px; border: 1px solid var(--line); vertical-align: top; }
.legal th { background: var(--surface); color: var(--ink); }
.legal .box {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 20px 22px;
  margin: 18px 0;
}
.legal .box p { margin: 6px 0; }
.steps { counter-reset: s; list-style: none; padding: 0 !important; }
.steps li { counter-increment: s; display: flex; gap: 14px; margin: 14px 0; }
.steps li::before {
  content: counter(s);
  flex: 0 0 30px;
  height: 30px;
  border-radius: 9px;
  background: var(--lime);
  color: var(--on-lime);
  font-weight: 900;
  display: grid;
  place-items: center;
}

/* ---------- responsive ---------- */
@media (max-width: 900px) {
  .hero .wrap, .split { grid-template-columns: 1fr; }
  .split.rev > :first-child { order: 0; }
  .phones { height: 520px; max-width: 460px; margin: 0 auto; width: 100%; }
  .phone { width: 220px; }
  .games, .cards.four { grid-template-columns: repeat(2, 1fr); }
  .nav-links { display: none; }
  .nav .btn { margin-left: auto; }
}
@media (max-width: 560px) {
  body { font-size: 16px; }
  .hero { padding-top: 44px; }
  .phones { height: 440px; }
  .phone { width: 185px; border-radius: 28px; }
  .phone img { border-radius: 22px; }
  .phones .p1 { left: 0; }
  .phones .p2 { right: 0; }
  .strip .wrap { grid-template-columns: repeat(2, 1fr); }
  .strip div.stat:nth-child(3) { border-left: 0; }
  .strip div.stat:nth-child(n + 3) { border-top: 1px solid var(--line); }
  .cards.two, .cards.four { grid-template-columns: 1fr; }
  .games { gap: 10px; }
  .game { padding: 14px; }
  .game h4 { font-size: 16px; }
  .duo .phone { width: 46%; }
  section.block { padding: 72px 0; }
  .legal table, .legal thead, .legal tbody, .legal tr, .legal th, .legal td { font-size: 14px; }
}
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .btn { transition: none; }
}

/* ---------- keyword landing pages ---------- */
.crumbs { font-size: 13px; font-weight: 800; color: var(--faint); margin-bottom: 16px; }
.crumbs a { color: var(--muted); text-decoration: none; }
.crumbs a:hover { color: var(--ink); }
.phones.single { display: flex; justify-content: center; align-items: center; }
.phones.single .phone { position: relative; transform: rotate(3deg); }
.display.sub { font-size: clamp(32px, 4.6vw, 48px); margin-top: 8px; }
section.block.tight { padding: 44px 0; }
.legal-like { max-width: 860px; }
.legal-like .steps { margin-top: 22px; }
.legal-like .list a, .faq a { color: var(--lime); }
.link-cards .game { text-decoration: none; display: block; }
.link-cards .game:hover { border-color: var(--lime); }
.footer-games { margin-top: 18px; }
.footer-games nav { margin-left: 0; gap: 10px 20px; }
.footer-games a { font-weight: 700; color: var(--faint); font-size: 13px; }

/* Cards that are links: no browser underline, keep the card's own colours. */
a.game, a.game:visited { text-decoration: none; color: inherit; display: block; }
a.game:hover { border-color: var(--lime); }
a.game small::after { content: ' →'; color: var(--lime); }
/* Inline text links ("More about math duels →") */
.head p a, .list a, .faq a, .legal-like a { text-decoration: none; font-weight: 800; }
.head p a:hover, .list a:hover, .faq a:hover, .legal-like a:hover { text-decoration: underline; text-underline-offset: 3px; }