:root {
  --color-background: #fafafa;
  --color-surface: #ffffff;
  --color-text-primary: #1a1a2e;
  --color-text-secondary: #6b7280;
  --color-cell-background: #ffffff;
  --color-cell-border: #e5e7eb;
  --color-cell-hover: #f3f4f6;
  --color-x: #6366f1;
  --color-o: #f43f5e;
  --color-button-background: #6366f1;
  --color-button-hover: #4f46e5;
  --color-winning-cell: #ecfdf5;
  --color-shadow: rgba(0, 0, 0, 0.06);
}

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  font-family: 'Inter', 'Segoe UI', system-ui, -apple-system, sans-serif;
  display: flex;
  justify-content: center;
  align-items: center;
  min-height: 100vh;
  background-color: var(--color-background);
  background-image:
    radial-gradient(ellipse at 20% 50%, rgba(99, 102, 241, 0.04) 0%, transparent 50%),
    radial-gradient(ellipse at 80% 50%, rgba(244, 63, 94, 0.04) 0%, transparent 50%);
}

.game-container {
  text-align: center;
  background-color: var(--color-surface);
  padding: 48px 56px;
  border-radius: 24px;
  box-shadow:
    0 1px 3px var(--color-shadow),
    0 8px 32px var(--color-shadow);
}

h1 {
  color: var(--color-text-primary);
  margin-bottom: 12px;
  font-size: 2em;
  font-weight: 700;
  letter-spacing: -0.5px;
}

.status {
  font-size: 1.1em;
  font-weight: 500;
  margin-bottom: 32px;
  color: var(--color-text-secondary);
  min-height: 1.6em;
}

.board {
  display: grid;
  grid-template-columns: repeat(3, 140px);
  grid-gap: 14px;
  margin: 0 auto 36px;
}

.cell {
  width: 140px;
  height: 140px;
  background-color: var(--color-cell-background);
  border: 2px solid var(--color-cell-border);
  border-radius: 16px;
  display: flex;
  justify-content: center;
  align-items: center;
  cursor: pointer;
  transition: background-color 0.2s, border-color 0.2s, transform 0.15s;
  user-select: none;
  overflow: hidden;
}

.cell:hover {
  background-color: var(--color-cell-hover);
  border-color: #d1d5db;
  transform: scale(1.03);
}

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

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

.player-icon {
  width: 70%;
  height: 70%;
}

.winning-cell {
  background-color: var(--color-winning-cell);
  border-color: #6ee7b7;
}

button {
  padding: 14px 32px;
  font-size: 1em;
  font-weight: 600;
  font-family: inherit;
  background-color: var(--color-button-background);
  color: var(--color-surface);
  border: none;
  border-radius: 12px;
  cursor: pointer;
  transition: background-color 0.2s, transform 0.15s;
}

button:hover {
  background-color: var(--color-button-hover);
  transform: translateY(-1px);
}

button:active {
  transform: translateY(0);
}