:root {
  --bg: #f5f7f8;
  --surface: #ffffff;
  --surface-2: #eef2f3;
  --ink: #182326;
  --muted: #617076;
  --line: #dce4e6;
  --accent: #176b61;
  --accent-dark: #0f5149;
  --warm: #d4a64a;
  --radius: 20px;
  --shadow: 0 18px 50px rgba(24, 35, 38, 0.08);
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}
* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body { margin: 0; background: var(--bg); color: var(--ink); line-height: 1.6; }
a { color: inherit; }
img, svg { max-width: 100%; }
.container { width: min(1120px, calc(100% - 40px)); margin: 0 auto; }
.site-header { position: sticky; top: 0; z-index: 20; background: rgba(245, 247, 248, 0.9); backdrop-filter: blur(14px); border-bottom: 1px solid rgba(220, 228, 230, 0.8); }
.nav { min-height: 72px; display: flex; align-items: center; justify-content: space-between; gap: 24px; }
.brand { display: inline-flex; align-items: center; gap: 12px; text-decoration: none; font-weight: 800; letter-spacing: -0.03em; }
.brand-mark { width: 36px; height: 36px; display: grid; place-items: center; border-radius: 12px; color: white; background: var(--accent); font-weight: 800; }
.nav-links { display: flex; align-items: center; gap: 24px; }
.nav-links a { text-decoration: none; color: var(--muted); font-weight: 650; }
.nav-links a:hover, .nav-links a[aria-current="page"] { color: var(--accent-dark); }
.hero { padding: 92px 0 72px; }
.hero-grid { display: grid; grid-template-columns: 1.2fr .8fr; gap: 56px; align-items: center; }
.eyebrow { display: inline-flex; align-items: center; gap: 8px; padding: 7px 11px; border: 1px solid var(--line); border-radius: 999px; background: var(--surface); color: var(--accent-dark); font-size: .85rem; font-weight: 750; }
h1, h2, h3 { line-height: 1.1; letter-spacing: -0.035em; }
h1 { margin: 22px 0 20px; font-size: clamp(2.65rem, 6vw, 5.5rem); max-width: 800px; }
h2 { font-size: clamp(2rem, 4vw, 3.2rem); margin: 0 0 18px; }
h3 { font-size: 1.25rem; margin: 0 0 12px; }
.lead { max-width: 720px; color: var(--muted); font-size: 1.15rem; }
.actions { display: flex; flex-wrap: wrap; gap: 12px; margin-top: 30px; }
.button { display: inline-flex; min-height: 46px; align-items: center; justify-content: center; padding: 0 18px; border-radius: 12px; text-decoration: none; font-weight: 750; border: 1px solid var(--line); background: var(--surface); }
.button.primary { background: var(--accent); color: white; border-color: var(--accent); }
.button:hover { transform: translateY(-1px); }
.hero-panel { border-radius: 28px; padding: 30px; background: var(--ink); color: white; box-shadow: var(--shadow); }
.hero-panel .muted { color: #b9c4c7; }
.signal { height: 140px; display: flex; align-items: end; gap: 8px; margin: 28px 0 10px; }
.signal span { flex: 1; min-width: 8px; border-radius: 8px 8px 2px 2px; background: linear-gradient(180deg, #72b9ae, #2d7c70); }
.signal span:nth-child(1){height:34%}.signal span:nth-child(2){height:55%}.signal span:nth-child(3){height:46%}.signal span:nth-child(4){height:75%}.signal span:nth-child(5){height:63%}.signal span:nth-child(6){height:88%}.signal span:nth-child(7){height:72%}.signal span:nth-child(8){height:100%}
.section { padding: 70px 0; }
.section-heading { max-width: 720px; margin-bottom: 30px; }
.muted { color: var(--muted); }
.grid-3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px; }
.card { display: block; padding: 26px; border: 1px solid var(--line); border-radius: var(--radius); background: var(--surface); box-shadow: 0 8px 30px rgba(24, 35, 38, 0.04); text-decoration: none; }
.card:hover { border-color: #bccbce; transform: translateY(-2px); }
.card .number { display: inline-grid; width: 36px; height: 36px; place-items: center; border-radius: 10px; background: var(--surface-2); color: var(--accent-dark); font-weight: 800; margin-bottom: 42px; }
.band { padding: 34px; display: grid; grid-template-columns: 1fr 1fr; gap: 30px; border-radius: 28px; background: #e4eceb; }
.checks { display: grid; gap: 14px; }
.check { padding: 14px 16px; background: rgba(255,255,255,.72); border-radius: 14px; }
.article-layout { display: grid; grid-template-columns: minmax(0, 760px) 1fr; gap: 60px; align-items: start; }
.prose { background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); padding: clamp(24px, 5vw, 48px); }
.prose h2 { margin-top: 42px; font-size: 1.8rem; }
.prose h3 { margin-top: 30px; }
.prose p, .prose li { color: #435156; }
.prose strong { color: var(--ink); }
.note { padding: 18px 20px; border-left: 4px solid var(--warm); background: #fbf6e9; border-radius: 0 12px 12px 0; }
.side-nav { position: sticky; top: 100px; display: grid; gap: 10px; }
.side-nav a { color: var(--muted); text-decoration: none; }
.side-nav a:hover { color: var(--accent); }
.footer { margin-top: 70px; padding: 44px 0; border-top: 1px solid var(--line); color: var(--muted); }
.footer-row { display: flex; justify-content: space-between; gap: 20px; flex-wrap: wrap; }
.footer-links { display: flex; gap: 18px; flex-wrap: wrap; }
.footer a { color: inherit; }
.page-head { padding: 72px 0 36px; }
.page-head h1 { font-size: clamp(2.6rem, 6vw, 4.8rem); }
@media (max-width: 820px) {
  .hero-grid, .grid-3, .band, .article-layout { grid-template-columns: 1fr; }
  .hero { padding-top: 60px; }
  .side-nav { position: static; }
  .nav { min-height: 64px; }
  .nav-links { gap: 14px; font-size: .92rem; }
}
@media (max-width: 560px) {
  .container { width: min(100% - 28px, 1120px); }
  .brand span:last-child { display: none; }
  .nav-links a:nth-child(2) { display: none; }
  .hero-panel { padding: 22px; }
}


/* Browser game */
.game-promo { padding-top: 18px; padding-bottom: 18px; }
.game-promo-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 28px;
  padding: 30px 34px;
  border: 1px solid var(--line);
  border-radius: 28px;
  background: var(--surface);
  box-shadow: 0 8px 30px rgba(24, 35, 38, 0.04);
}
.game-promo-inner h2 { margin-top: 14px; margin-bottom: 10px; font-size: clamp(1.8rem, 4vw, 2.7rem); }
.game-promo-inner p { margin: 0; max-width: 720px; }
.game-promo-inner .button { flex: 0 0 auto; }

.game-page { min-height: 100vh; }
.game-main { padding: 42px 0 8px; }
.game-container { width: min(560px, calc(100% - 28px)); }
.game-card {
  padding: clamp(20px, 5vw, 36px);
  border: 1px solid var(--line);
  border-radius: 28px;
  background: var(--surface);
  box-shadow: var(--shadow);
}
.game-heading { text-align: center; }
.game-heading h1 { margin: 14px 0 10px; font-size: clamp(2.2rem, 10vw, 4rem); }
.game-heading p { margin: 0 auto 24px; max-width: 440px; }

.game-mode {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 6px;
  padding: 5px;
  border-radius: 14px;
  background: var(--surface-2);
}
.mode-button {
  min-height: 44px;
  border: 0;
  border-radius: 10px;
  background: transparent;
  color: var(--muted);
  font: inherit;
  font-weight: 750;
  cursor: pointer;
  touch-action: manipulation;
}
.mode-button.is-active {
  background: var(--surface);
  color: var(--accent-dark);
  box-shadow: 0 3px 12px rgba(24, 35, 38, .08);
}

.game-score {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 8px;
  margin: 18px 0 12px;
}
.score-item {
  min-width: 0;
  padding: 10px 6px;
  border: 1px solid var(--line);
  border-radius: 13px;
  text-align: center;
  background: var(--bg);
}
.score-label {
  display: block;
  min-height: 2.5em;
  color: var(--muted);
  font-size: .76rem;
  line-height: 1.25;
}
.score-item strong { display: block; margin-top: 2px; font-size: 1.45rem; line-height: 1.2; }

.game-status {
  min-height: 32px;
  margin: 12px 0;
  text-align: center;
  color: var(--accent-dark);
  font-weight: 800;
}

.game-board {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 8px;
  width: min(100%, 420px);
  margin: 0 auto;
  padding: 8px;
  border-radius: 24px;
  background: var(--surface-2);
  user-select: none;
  -webkit-user-select: none;
}
.game-cell {
  aspect-ratio: 1;
  min-width: 0;
  padding: 0;
  border: 0;
  border-radius: 17px;
  background: var(--surface);
  color: var(--ink);
  font: inherit;
  font-size: clamp(3.3rem, 18vw, 5.6rem);
  font-weight: 650;
  line-height: 1;
  cursor: pointer;
  touch-action: manipulation;
  -webkit-tap-highlight-color: transparent;
  transition: transform .08s ease, background .15s ease, box-shadow .15s ease;
  box-shadow: 0 3px 12px rgba(24, 35, 38, .045);
}
.game-cell:not(:disabled):active { transform: scale(.96); }
.game-cell.is-x { color: var(--accent-dark); }
.game-cell.is-o { color: #9a6a10; }
.game-cell.is-win {
  background: #dcefea;
  box-shadow: inset 0 0 0 2px #8ac2b8;
}
.game-cell:disabled { cursor: default; opacity: 1; }

.game-actions {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px;
  margin-top: 18px;
}
.game-actions .button {
  width: 100%;
  min-height: 48px;
  cursor: pointer;
  font: inherit;
  touch-action: manipulation;
}
.game-note { margin: 12px 0 0; text-align: center; color: var(--muted); font-size: .78rem; }

@media (max-width: 560px) {
  .game-promo-inner { align-items: stretch; flex-direction: column; padding: 24px; }
  .game-promo-inner .button { width: 100%; }
  .game-main { padding-top: 22px; }
  .game-card { border-radius: 22px; }
  .game-board { gap: 6px; padding: 6px; border-radius: 20px; }
  .game-cell { border-radius: 14px; }
  .game-actions { grid-template-columns: 1fr; }
}