:root {
  color-scheme: light;
  font-family: "Avenir Next", Avenir, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  background: #f4f1e9;
  color: #283d35;
  font-synthesis: none;
  --paper: #f4f1e9;
  --surface: #fffdf8;
  --ink: #283d35;
  --muted: #656c60;
  --line: #dbddd0;
  --x: #ba5037;
  --o: #315e51;
}
* { box-sizing: border-box; }
[hidden] { display: none !important; }
body { margin: 0; min-height: 100dvh; background-image: radial-gradient(#45514312 0.7px, transparent 0.7px); background-size: 12px 12px; }
button, select, input { font: inherit; }
button, select, summary, .size-choices label { -webkit-tap-highlight-color: transparent; touch-action: manipulation; }
button, summary { cursor: pointer; }
button:focus-visible, select:focus-visible, summary:focus-visible, a:focus-visible { outline: 3px solid var(--o); outline-offset: 4px; }
button svg, summary svg { width: 18px; height: 18px; fill: none; stroke: currentColor; stroke-width: 1.6; stroke-linecap: round; stroke-linejoin: round; flex-shrink: 0; }
.app-shell { width: min(100%, 1100px); margin: auto; padding: 30px 48px 24px; }
.brandbar { display: flex; align-items: center; gap: 32px; padding-bottom: 24px; border-bottom: 1px solid var(--line); }
.brand { display: flex; gap: 12px; align-items: center; color: var(--ink); text-decoration: none; font-size: 23px; font-weight: 750; letter-spacing: -1px; }
.brand-mark { width: 34px; height: 34px; fill: none; stroke: var(--x); stroke-width: 2.6; stroke-linecap: round; }
.brand-dot { color: var(--x); }
.brand-note { color: var(--muted); font-size: 12px; }
.edition { margin-left: auto; font-size: 10px; letter-spacing: 1.4px; text-transform: uppercase; color: var(--muted); }
.duel-layout { display: grid; grid-template-columns: minmax(250px, 310px) minmax(0, 470px); justify-content: space-between; align-items: center; gap: 60px; padding: 46px 0 38px; }
.eyebrow { margin: 0 0 18px; font-size: 10px; font-weight: 650; letter-spacing: 2px; text-transform: uppercase; color: var(--x); }
h1 { margin: 0; font-family: Georgia, "Times New Roman", serif; font-weight: 400; font-size: 68px; letter-spacing: -3px; line-height: 0.99; }
h1 em { color: var(--o); font-weight: 400; }
.intro { margin: 22px 0 30px; font-size: 14px; line-height: 1.8; color: var(--muted); }
fieldset { min-width: 0; margin: 0; padding: 0; border: 0; }
legend, .setup label > span { display: block; padding: 0; margin-bottom: 9px; font-size: 11px; font-weight: 600; color: var(--muted); }
.segmented { display: grid; grid-template-columns: 1fr 1fr; gap: 8px; }
.segmented button { display: flex; align-items: center; justify-content: center; gap: 10px; min-height: 52px; border: 1px solid var(--line); border-radius: 12px; background: #fffdf87d; color: var(--ink); font-size: 14px; font-weight: 600; transition: background-color 150ms, border-color 150ms; }
.segmented button[aria-pressed="true"] { color: var(--surface); background: var(--o); border-color: var(--o); box-shadow: 0 3px 0 #24493f; }
.segmented button[aria-pressed="false"] svg { color: var(--muted); }
.size-and-options { position: relative; margin-top: 24px; }
.size-choices { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 8px; }
.size-choices label { position: relative; display: grid; place-items: center; min-height: 46px; border: 1px solid var(--line); border-radius: 10px; background: #fffdf87d; cursor: pointer; }
.size-choices label > span { margin: 0; font-size: 14px; font-weight: 600; color: var(--ink); }
.size-choices input { position: absolute; inset: 0; width: 100%; height: 100%; opacity: 0; margin: 0; cursor: pointer; }
.size-choices label:has(input:checked) { border-color: var(--x); background: #f6e8de; box-shadow: inset 0 0 0 1px var(--x); }
.size-choices label:has(input:checked) span { color: #9c412c; }
.size-choices label:has(input:focus-visible) { outline: 3px solid var(--o); outline-offset: 4px; }
.setup select { width: 100%; min-height: 44px; border: 1px solid var(--line); border-radius: 8px; background: var(--surface); color: var(--ink); padding: 0 8px; font-size: 16px; }
.watch-setup { display: grid; grid-template-columns: 1fr 1fr; gap: 10px; min-width: 0; }
.watch-setup label { min-width: 0; }
.watch-setup select { min-height: 52px; }
.game-options { margin-top: 12px; }
.game-options summary { display: flex; align-items: center; gap: 8px; width: fit-content; min-height: 44px; color: var(--muted); font-size: 11px; list-style: none; }
.game-options summary::-webkit-details-marker { display: none; }
.game-options summary::after { content: '+'; margin-left: 8px; font-size: 16px; }
.game-options[open] summary::after { content: '−'; }
.options-grid { display: grid; grid-template-columns: minmax(0, 1.35fr) minmax(0, 1fr); gap: 10px; padding: 12px 0; }
.options-grid label { min-width: 0; }
.side-note { display: flex; align-items: center; gap: 8px; margin-top: 30px; padding-top: 22px; border-top: 1px solid var(--line); }
.side-note > span { font-family: Georgia, serif; font-size: 44px; line-height: 1; color: #afb6a6; }
.side-note > span:first-child { transform: rotate(-10deg); }
.side-note p { margin: 0 0 0 10px; font-size: 11px; line-height: 1.6; color: var(--muted); }
.game-card { min-width: 0; }
.game-topbar { display: flex; align-items: center; justify-content: space-between; gap: 8px; min-height: 44px; margin: 0 4px 16px; }
.turn-status { display: flex; align-items: center; min-width: 0; gap: 9px; }
.turn-dot { flex-shrink: 0; width: 7px; height: 7px; border-radius: 50%; background: var(--x); box-shadow: 0 0 0 4px #ba50370c; }
.turn-dot[data-mark="O"] { background: var(--o); box-shadow: 0 0 0 4px #315e510c; }
.turn-dot[data-state="paused"], .turn-dot[data-state="draw"] { background: var(--muted); box-shadow: none; }
.status { margin: 0; font-size: 13px; font-weight: 600; }
.actions { display: flex; gap: 4px; flex-shrink: 0; }
.button { display: inline-flex; justify-content: center; align-items: center; gap: 7px; min-height: 44px; padding: 0 12px; border: 1px solid var(--line); border-radius: 10px; background: var(--surface); color: var(--ink); font-size: 11px; font-weight: 600; }
.button--quiet { background: transparent; }
.button:disabled { opacity: 0.45; cursor: default; }
.move-error:has(#error:not([hidden])) { margin-bottom: 14px; padding: 12px; border: 1px solid #dfb5a4; background: #f9e8de; border-radius: 12px; }
#error { color: #963d29; line-height: 1.5; font-size: 13px; margin: 0 0 10px; }
.board-frame { padding: 12px; border: 1px solid #d5d8c8; border-radius: 26px; background: #e2e6d9; box-shadow: 0 4px 0 #c8cdba, 0 22px 46px -18px #3f49342b, inset 0 1px 0 #fff8; }
.board { --board-size: 3; display: grid; grid-template-columns: repeat(var(--board-size), minmax(0, 1fr)); grid-template-rows: repeat(var(--board-size), minmax(0, 1fr)); gap: 8px; width: 100%; aspect-ratio: 1; isolation: isolate; }
.cell { position: relative; display: block; width: 100%; height: 100%; min-width: 0; min-height: 0; padding: 0; border: 1px solid #fffdf8; border-radius: 15px; appearance: none; background: var(--surface); box-shadow: 0 3px 0 #ced3c3, 0 3px 5px #3e4d3510; color: var(--x); opacity: 1; user-select: none; transition: background-color 140ms, box-shadow 140ms; }
.cell:disabled { cursor: default; }
.cell:focus-visible { outline-offset: -4px; z-index: 1; }
.cell--o { color: var(--o); background: #f7f9f2; }
.cell--x { background: #fff6ed; }
.cell--winner { background: #d4e5c1; border-color: #bdd2a7; box-shadow: 0 3px 0 #adbf97; }
.cell .mark { position: absolute; width: 52%; height: 52%; top: 24%; left: 24%; pointer-events: none; filter: drop-shadow(0 2px 0 #24362810); }
.cell--new .mark { animation: mark-in 220ms cubic-bezier(.2,.8,.3,1.2) both; }
@keyframes mark-in { from { opacity: 0; transform: scale(.65) rotate(-8deg); } to { opacity: 1; transform: scale(1) rotate(0); } }
@media (hover: hover) and (pointer: fine) {
  .cell:not(:disabled):hover { background: #f5eddf; box-shadow: 0 3px 0 #c1c7b4, inset 0 0 0 1px #e2d5c3; }
  .button:not(:disabled):hover, .segmented button[aria-pressed="false"]:hover, .size-choices label:not(:has(input:checked)):hover { border-color: #8d9c84; background: #eaf0e2; }
  .game-options summary:hover { color: var(--ink); }
}
.cell:not(:disabled):active { background: #ece4d6; }
.score { display: grid; grid-template-columns: 1fr .75fr 1fr; align-items: center; margin: 24px 4px 0; padding: 0 0 16px; border-bottom: 1px solid var(--line); }
.score-player { display: flex; align-items: center; gap: 12px; }
.score-player--o { justify-content: flex-end; }
.score-symbol { display: grid; place-items: center; width: 36px; height: 36px; border-radius: 10px; background: #eadfd2; color: var(--x); font-size: 29px; line-height: 1; }
.score-player--o .score-symbol { color: var(--o); background: #e1e7d9; }
.score-player > div, .score-draw { display: flex; flex-direction: column; gap: 2px; }
.score span:not(.score-symbol) { font-size: 10px; font-weight: 500; color: var(--muted); }
.score strong { font-size: 22px; line-height: 1.2; font-weight: 600; font-variant-numeric: tabular-nums; }
.score-draw { text-align: center; border-inline: 1px solid var(--line); }
.score-draw strong { color: var(--muted); }
.rules { margin: 16px 0 0; text-align: center; color: var(--muted); font-size: 11px; line-height: 1.5; }
.footer { display: flex; justify-content: space-between; padding-top: 18px; border-top: 1px solid var(--line); font-size: 10px; letter-spacing: .2px; color: var(--muted); }

@media (max-width: 899px) {
  .app-shell { width: min(100%, 520px); padding: 24px; }
  .brandbar { padding: 0; border: 0; margin-bottom: 24px; justify-content: space-between; }
  .brand-note { font-size: 10px; max-width: 105px; text-align: right; }
  .edition, .hero, .side-note, .footer { display: none; }
  .duel-layout { display: block; padding: 0; }
  .setup { margin-bottom: 16px; }
  .size-and-options { display: grid; grid-template-columns: minmax(0, 1fr) auto; align-items: end; gap: 16px; margin-top: 14px; }
  .game-options { margin: 0; }
  .game-options summary { min-height: 46px; }
  .game-options summary::after { display: none; }
  .options-grid { position: absolute; z-index: 5; top: calc(100% + 10px); inset-inline: 0; padding: 16px; border: 1px solid var(--line); border-radius: 14px; background: var(--surface); box-shadow: 0 12px 32px #283d3520; }
  .game-options[open] summary { color: var(--o); }
  .game-card { width: min(100%, max(270px, calc(100svh - 292px))); margin-inline: auto; }
  .game-topbar { margin: 0 2px 10px; }
  .score { margin-top: 18px; }
}
@media (max-width: 599px) {
  .app-shell { width: min(100%, 420px); padding: max(16px, env(safe-area-inset-top)) max(16px, env(safe-area-inset-right)) max(16px, env(safe-area-inset-bottom)) max(16px, env(safe-area-inset-left)); }
  .brandbar { margin-bottom: 18px; }
  .brand { font-size: 22px; gap: 9px; }
  .brand-mark { width: 30px; height: 30px; }
  #opponent-picker legend, .board-size-picker legend { position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px; overflow: hidden; clip-path: inset(50%); white-space: nowrap; }
  .segmented button { min-height: 44px; font-size: 13px; }
  .size-and-options { margin-top: 10px; gap: 12px; }
  .size-choices { gap: 6px; }
  .size-choices label { min-height: 44px; }
  .size-choices label > span { font-size: 12px; }
  .game-options summary { min-height: 44px; font-size: 10px; gap: 5px; }
  .game-options summary svg { width: 16px; height: 16px; }
  .setup { margin-bottom: 10px; }
  .game-card { width: min(100%, max(262px, calc(100svh - 306px))); }
  .game-topbar { margin-bottom: 8px; }
  .status { font-size: 12px; }
  .button { font-size: 10px; padding-inline: 9px; gap: 5px; }
  .button svg { width: 15px; height: 15px; }
  .board-frame { padding: 8px; border-radius: 20px; box-shadow: 0 3px 0 #c8cdba, 0 16px 32px -18px #3f493433; }
  .board { gap: 6px; }
  .cell { border-radius: 11px; }
  .score { margin-top: 16px; padding-bottom: 10px; }
  .score-player { gap: 8px; }
  .score-symbol { width: 30px; height: 30px; border-radius: 8px; font-size: 25px; }
  .score strong { font-size: 19px; }
  .rules { margin-top: 10px; font-size: 10px; }
  .watch-setup select { min-height: 44px; }
}
@media (max-width: 350px) {
  .app-shell { padding: 12px; }
  .brandbar { margin-bottom: 12px; }
  .brand-note { max-width: 90px; font-size: 9px; }
  .size-and-options { margin-top: 8px; gap: 8px; }
  .setup { margin-bottom: 8px; }
  .turn-status { gap: 7px; }
  .status { font-size: 11px; }
  .score { margin-top: 12px; padding-bottom: 8px; }
  .score-symbol { display: none; }
  .score-player--o { text-align: right; }
  .rules { margin-top: 8px; }
}
@media (min-width: 900px) and (max-height: 800px) and (min-height: 551px) {
  .app-shell { padding-top: 22px; }
  .duel-layout { padding-block: 24px; grid-template-columns: minmax(250px, 310px) minmax(0, min(420px, max(278px, calc(100svh - 300px)))); gap: 44px; }
  h1 { font-size: 56px; }
  .intro { margin-block: 16px 22px; }
  .side-note { display: none; }
  .footer { display: none; }
}
@media (min-width: 560px) and (max-height: 550px) {
  .app-shell { position: relative; width: fit-content; max-width: 100%; padding: max(12px, env(safe-area-inset-top)) max(16px, env(safe-area-inset-right)) max(12px, env(safe-area-inset-bottom)) max(16px, env(safe-area-inset-left)); }
  .brandbar { position: absolute; top: 18px; border: 0; padding: 0; }
  .brand { font-size: 21px; gap: 8px; }
  .brand-mark { width: 28px; height: 28px; }
  .brand-note, .edition, .hero, .side-note, .footer { display: none; }
  .duel-layout { display: grid; grid-template-columns: 240px minmax(260px, min(420px, calc(100svh - 118px))); gap: 28px; align-items: start; padding: 0; }
  .setup-panel { padding-top: 52px; }
  .segmented button, .watch-setup select { min-height: 44px; }
  .size-and-options { display: block; margin-top: 14px; }
  .game-card { width: auto; margin: 0; }
  .game-options { margin-top: 4px; }
  .game-topbar { margin: 0 0 6px; }
  .status { font-size: 11px; }
  .button { padding-inline: 7px; font-size: 10px; }
  #new-game svg { display: none; }
  .board-frame { padding: 7px; border-radius: 18px; }
  .board { gap: 5px; }
  .cell { border-radius: 10px; }
  .score { margin-top: 10px; padding: 0; border: 0; }
  .score-player { gap: 6px; }
  .score-symbol { width: 27px; height: 27px; font-size: 23px; }
  .score strong { font-size: 16px; }
  .score span:not(.score-symbol) { font-size: 9px; }
  .rules { position: absolute; top: 270px; left: max(16px, env(safe-area-inset-left)); width: 240px; text-align: left; font-size: 10px; }
  .setup-panel:has(.game-options[open]) + .game-card .rules { display: none; }
  .options-grid { position: static; padding: 4px 0; border: 0; background: transparent; box-shadow: none; }
}
@media (prefers-reduced-motion: reduce) { *, *::before, *::after { animation: none !important; transition: none !important; } }