:root {
  color-scheme: light;
  --background: #f5f7fb;
  --panel: #ffffff;
  --ink: #1c2331;
  --muted: #687287;
  --line: #d9dfeb;
  --accent: #0f766e;
  --accent-dark: #115e59;
  --x-color: #d94660;
  --o-color: #2563eb;
  --shadow: 0 20px 60px rgba(26, 38, 68, 0.16);
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-height: 100vh;
  font-family: Arial, Helvetica, sans-serif;
  color: var(--ink);
  background:
    linear-gradient(135deg, rgba(15, 118, 110, 0.14), transparent 38%),
    linear-gradient(315deg, rgba(217, 70, 96, 0.12), transparent 34%),
    var(--background);
}

button {
  font: inherit;
}

.game {
  min-height: 100vh;
  display: grid;
  place-items: center;
  padding: 24px;
}

.panel {
  width: min(100%, 520px);
  padding: 28px;
  background: var(--panel);
  border: 1px solid rgba(217, 223, 235, 0.9);
  border-radius: 8px;
  box-shadow: var(--shadow);
}

.header {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 16px;
}

.eyebrow {
  margin: 0 0 6px;
  color: var(--accent);
  font-size: 0.78rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

h1 {
  margin: 0;
  font-size: clamp(2rem, 7vw, 3.4rem);
  line-height: 1;
}

.reset-button,
.new-round-button {
  border: 0;
  border-radius: 8px;
  color: #ffffff;
  background: var(--accent);
  cursor: pointer;
  transition: transform 160ms ease, background 160ms ease;
}

.reset-button {
  flex: 0 0 auto;
  min-height: 40px;
  padding: 0 14px;
}

.new-round-button {
  width: 100%;
  min-height: 48px;
  margin-top: 22px;
  font-weight: 700;
}

.reset-button:hover,
.new-round-button:hover {
  background: var(--accent-dark);
  transform: translateY(-1px);
}

.scoreboard {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 10px;
  margin: 24px 0 18px;
}

.scoreboard div {
  min-width: 0;
  padding: 12px;
  border: 1px solid var(--line);
  border-radius: 8px;
  text-align: center;
  background: #fbfcff;
}

.score-label {
  display: block;
  color: var(--muted);
  font-size: 0.82rem;
}

.scoreboard strong {
  display: block;
  margin-top: 4px;
  font-size: 1.65rem;
}

.status {
  min-height: 28px;
  margin: 0 0 14px;
  color: var(--muted);
  font-size: 1.08rem;
  font-weight: 700;
  text-align: center;
}

.board {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 10px;
  aspect-ratio: 1;
}

.cell {
  display: grid;
  place-items: center;
  width: 100%;
  aspect-ratio: 1;
  border: 2px solid var(--line);
  border-radius: 8px;
  color: var(--ink);
  background: #f8fafc;
  cursor: pointer;
  font-size: clamp(2.4rem, 16vw, 5.25rem);
  font-weight: 900;
  line-height: 1;
  transition: border-color 160ms ease, background 160ms ease, transform 160ms ease;
}

.cell:hover:not(:disabled) {
  border-color: var(--accent);
  background: #eefdfa;
  transform: translateY(-1px);
}

.cell:disabled {
  cursor: default;
}

.cell.x {
  color: var(--x-color);
}

.cell.o {
  color: var(--o-color);
}

.cell.winning {
  border-color: var(--accent);
  background: #dff7f1;
}

@media (max-width: 520px) {
  .game {
    padding: 14px;
  }

  .panel {
    padding: 20px;
  }

  .header {
    align-items: stretch;
    flex-direction: column;
  }

  .reset-button {
    width: 100%;
  }

  .scoreboard {
    gap: 8px;
  }

  .scoreboard div {
    padding: 10px 6px;
  }
}