:root {
  --bg: #0f172a;
  --panel: #1e293b;
  --cell: #334155;
  --cell-hover: #475569;
  --text: #e2e8f0;
  --x: #38bdf8;
  --o: #fb923c;
  --win: #4ade80;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  min-height: 100vh;
  display: grid;
  place-items: center;
  background: var(--bg);
  color: var(--text);
  font-family: system-ui, -apple-system, "Segoe UI", sans-serif;
}

main {
  width: min(92vw, 380px);
  text-align: center;
}

h1 { margin: 0 0 0.5rem; }

#status {
  min-height: 1.5rem;
  margin: 0 0 1rem;
  font-size: 1.1rem;
}

.board {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 8px;
  padding: 8px;
  background: var(--panel);
  border-radius: 12px;
}

.cell {
  aspect-ratio: 1;
  border: 0;
  border-radius: 8px;
  background: var(--cell);
  font-size: clamp(2.5rem, 16vw, 4rem);
  font-weight: 700;
  cursor: pointer;
  transition: background 0.15s;
}

.cell:hover:not(:disabled) { background: var(--cell-hover); }
.cell:focus-visible, #restart:focus-visible { outline: 3px solid var(--text); outline-offset: 2px; }
.cell:disabled { cursor: default; }
.cell.x { color: var(--x); }
.cell.o { color: var(--o); }
.cell.win { background: var(--win); color: var(--bg); }

.scoreboard {
  display: flex;
  justify-content: space-around;
  margin: 1.25rem 0;
}

.scoreboard strong { display: block; font-size: 1.5rem; }

#restart {
  padding: 0.6rem 1.5rem;
  border: 0;
  border-radius: 8px;
  background: var(--x);
  color: var(--bg);
  font-size: 1rem;
  font-weight: 600;
  cursor: pointer;
}

#restart:hover { filter: brightness(1.1); }