body {
  font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
  background: linear-gradient(135deg, #0f2027, #203a43, #2c5364);
  color: #fff;
  text-align: center;
  margin: 0;
  padding: 0;
}

h1 {
  margin-top: 30px;
  font-size: 2.5rem;
  color: #00d8ff;
  text-shadow: 1px 1px 3px rgba(0,0,0,0.7);
}

#info {
  font-size: 1.2rem;
  margin: 10px 0 20px;
  color: #ffd700;
}

#board {
  display: grid;
  grid-template-columns: repeat(20, 35px);
  grid-template-rows: repeat(20, 35px);
  gap: 2px;
  margin: 0 auto 30px;
  width: max-content;
  background: rgba(255, 255, 255, 0.1);
  border: 3px solid #00d8ff;
  box-shadow: 0 0 20px rgba(0,0,0,0.5);
  border-radius: 12px;
  padding: 5px;
}

#board div {
  width: 35px;
  height: 35px;
  background: #1a1a1a;
  border: 1px solid #333;
  font-size: 22px;
  font-weight: bold;
  line-height: 35px;
  text-align: center;
  cursor: pointer;
  color: white;
  transition: 0.2s;
  user-select: none;
  border-radius: 5px;
}

#board div:hover {
  background: #2a2a2a;
  transform: scale(1.05);
}

#board div.X {
  color: #00d8ff;
  text-shadow: 0 0 5px #00d8ff;
}

#board div.O {
  color: #ff2f7f;
  text-shadow: 0 0 5px #ff2f7f;
}

footer {
  padding: 20px;
  font-size: 0.9rem;
  color: #bbb;
}