body {
  background: #f7f7f7;
  font-family: 'Segoe UI', 'Arial', sans-serif;
  display: flex;
  justify-content: center;
  align-items: center;
  height: 100vh;
  margin: 0;
}
.container {
  background: #fff;
  padding: 2rem 2.5rem;
  border-radius: 16px;
  box-shadow: 0 4px 24px rgba(0,0,0,0.08);
  text-align: center;
}
h1 {
  margin-bottom: 1.5rem;
  color: #333;
}
.board {
  display: grid;
  grid-template-columns: repeat(3, 80px);
  grid-template-rows: repeat(3, 80px);
  gap: 10px;
  margin-bottom: 1.2rem;
}
.cell {
  width: 80px;
  height: 80px;
  background: #e9ecef;
  border-radius: 10px;
  font-size: 2.5rem;
  color: #222;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: background 0.2s;
}
.cell:hover {
  background: #d0ebff;
}
.status {
  min-height: 2rem;
  font-size: 1.1rem;
  color: #555;
  margin-bottom: 1rem;
}
button#restart {
  padding: 0.5rem 1.5rem;
  font-size: 1rem;
  border: none;
  border-radius: 8px;
  background: #339af0;
  color: #fff;
  cursor: pointer;
  transition: background 0.2s;
}
button#restart:hover {
  background: #1971c2;
}