:root {
  color-scheme: dark;
  --ink: #f3f6f1;
  --muted: #9eaaa2;
  --night: #0b100e;
  --panel: #131c18;
  --line: #2d3a33;
  --lime: #c9f45b;
  --mint: #72dab0;
  --berry: #ff668f;
  --display: "Arial Black", "Helvetica Neue", Arial, sans-serif;
  --body: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}

* { box-sizing: border-box; }
html { min-width: 280px; background: var(--night); }
body {
  min-height: 100vh;
  margin: 0;
  color: var(--ink);
  background: radial-gradient(circle at 84% 8%, rgba(114, 218, 176, 0.11), transparent 30rem), var(--night);
  font-family: var(--body);
  line-height: 1.5;
}
a { color: inherit; }
button { color: inherit; font: inherit; }
.site-header, main, footer { width: min(1100px, calc(100% - 40px)); margin-inline: auto; }
.site-header { display: flex; align-items: center; justify-content: space-between; min-height: 80px; border-bottom: 1px solid var(--line); }
.brand { display: inline-flex; align-items: center; gap: 11px; font-weight: 850; text-decoration: none; }
.brand-mark { display: grid; width: 34px; height: 34px; place-items: center; color: var(--night); background: var(--lime); border-radius: 9px; font-family: var(--display); }
.site-header p { margin: 0; color: var(--muted); font-size: 0.7rem; font-weight: 800; letter-spacing: 0.13em; text-transform: uppercase; }
.site-header p span, .eyebrow { color: var(--lime); }
.intro { display: grid; grid-template-columns: 1fr minmax(260px, 410px); gap: 60px; align-items: end; padding: 66px 0 42px; }
.intro p, .rules p { color: var(--muted); }
.intro > p { margin-bottom: 4px; }
.eyebrow { margin: 0 0 10px; font-size: 0.72rem; font-weight: 850; letter-spacing: 0.18em; text-transform: uppercase; }
h1, h2, p { margin-top: 0; }
h1 { margin-bottom: 0; font-family: var(--display); font-size: clamp(3.5rem, 9vw, 7rem); line-height: 0.88; letter-spacing: -0.07em; }
.game-shell { overflow: hidden; background: var(--panel); border: 1px solid var(--line); border-radius: 16px; }
.scorebar { display: grid; grid-template-columns: 1fr minmax(220px, 2fr) 1fr; gap: 20px; align-items: center; padding: 18px 24px; border-bottom: 1px solid var(--line); }
.scorebar > div { display: grid; }
.scorebar__right { text-align: right; }
.scorebar span { color: var(--muted); font-size: 0.65rem; font-weight: 850; letter-spacing: 0.14em; text-transform: uppercase; }
.scorebar strong { color: var(--lime); font: 800 2rem/1 ui-monospace, SFMono-Regular, Menlo, monospace; }
.scorebar p { margin: 0; color: var(--muted); font-size: 0.78rem; text-align: center; }
.play-area { display: grid; grid-template-columns: minmax(0, 1fr) 240px; gap: 30px; padding: clamp(16px, 4vw, 38px); }
.board-wrap { min-width: 0; padding: 10px; background: #070b09; border: 1px solid #34433b; border-radius: 13px; }
.board { display: grid; grid-template-columns: repeat(20, 1fr); gap: 2px; width: min(100%, 520px); aspect-ratio: 1; margin: auto; touch-action: none; }
.cell { min-width: 0; background: #17211c; border-radius: 20%; }
.cell--snake { background: var(--mint); }
.cell--head { background: var(--lime); box-shadow: 0 0 0 2px #17220c inset; }
.cell--food { background: var(--berry); border-radius: 50%; box-shadow: 0 0 12px rgba(255, 102, 143, 0.46); transform: scale(0.72); }
.controls { display: flex; flex-direction: column; justify-content: space-between; gap: 30px; }
.control-actions { display: grid; grid-template-columns: 1fr 1fr; gap: 8px; }
.control-actions button, .d-pad button { min-height: 44px; background: #1b2821; border: 1px solid #425148; border-radius: 8px; font-weight: 800; cursor: pointer; touch-action: manipulation; }
.control-actions button:hover, .control-actions button:focus-visible, .d-pad button:hover, .d-pad button:focus-visible { color: var(--night); background: var(--lime); border-color: var(--lime); }
.control-actions button:disabled { opacity: 0.45; cursor: default; }
.d-pad { display: grid; grid-template-columns: repeat(3, 56px); grid-template-rows: repeat(3, 56px); gap: 7px; align-self: center; touch-action: none; }
.d-pad button { font-size: 1.35rem; }
.d-pad__up { grid-column: 2; }
.d-pad__left { grid-column: 1; grid-row: 2; }
.d-pad__right { grid-column: 3; grid-row: 2; }
.d-pad__down { grid-column: 2; grid-row: 3; }
.controls > p { margin: 0; color: var(--muted); font-size: 0.78rem; }
.controls > p strong { color: var(--ink); }
.rules { display: grid; grid-template-columns: 0.7fr 1fr 1fr; gap: 40px; align-items: start; padding: 90px 0; }
.rules h2 { margin: 0; font-family: var(--display); font-size: clamp(2rem, 4vw, 3.8rem); line-height: 0.98; letter-spacing: -0.05em; }
.rules > p:last-child { margin: 0; }
footer { display: flex; justify-content: space-between; padding: 28px 0 42px; color: var(--muted); border-top: 1px solid var(--line); font-size: 0.8rem; }
footer a { color: var(--ink); font-weight: 750; text-decoration: none; }
footer p { margin: 0; }

@media (max-width: 760px) {
  .site-header, main, footer { width: min(100% - 24px, 640px); }
  .intro { grid-template-columns: 1fr; gap: 20px; padding-top: 52px; }
  .play-area { grid-template-columns: 1fr; }
  .controls { display: grid; grid-template-columns: 1fr 1.2fr; align-items: center; }
  .controls > p { grid-column: 1 / -1; }
  .rules { grid-template-columns: 1fr; gap: 20px; }
}

@media (max-width: 500px) {
  .site-header { min-height: 68px; }
  .intro { padding: 46px 0 32px; }
  .scorebar { grid-template-columns: 1fr 1fr; padding: 14px; }
  .scorebar p { grid-column: 1 / -1; grid-row: 2; }
  .play-area { padding: 10px; }
  .board { gap: 1px; }
  .controls { grid-template-columns: 1fr; }
  .d-pad { grid-template-columns: repeat(3, 62px); grid-template-rows: repeat(3, 54px); }
  footer { display: block; }
  footer p { margin-top: 6px; }
}

@media (prefers-reduced-motion: reduce) { * { transition: none !important; } }