body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Oxygen;
  background: #ffffff;
  color: #333;
  display: flex;
  align-items: center;
  justify-content: center;
  height: 100vh;
  flex-direction: column;
  padding: 20px;
}

.container {
  text-align: center;
}

.board {
  display: grid;
  grid-template-columns: repeat(3, 100px);
  grid-template-rows: repeat(3, 100px);
  gap: 10px;
  margin: 20px auto;
}

.about-button {
  background-color: #007aff;
  color: white;
  border: none;
  padding: 10px 18px;
  font-size: 16px;
  border-radius: 8px;
  cursor: pointer;
  transition: background-color 0.2s ease;
}

.about-button:hover {
  background-color: #005bb5;
}


.cell {
  width: 100px;
  height: 100px;
  background-color: #f0f0f0;
  display: flex;
  justify-content: center;
  align-items: center;
  font-size: 3rem;
  border-radius: 12px;
  cursor: pointer;
  position: relative;
  user-select: none;
}

.cell.x::before {
  content: "X";
  color: red;
  animation: fire 0.6s ease-out;
}

.cell.o::before {
  content: "O";
  color: blue;
  animation: fire 0.6s ease-out;
}

@keyframes fire {
  0% {
    transform: scale(0.5);
    opacity: 0.2;
  }

  100% {
    transform: scale(1);
    opacity: 1;
  }
}

button {
  padding: 10px 20px;
  font-size: 16px;
  background-color: #333;
  color: white;
  border: none;
  border-radius: 8px;
  cursor: pointer;
}

button:hover {
  background-color: #555;
}

.status {
  margin: 15px 0;
  font-size: 1.2rem;
}

.spacer {
  height: 20px;
}

footer {
  margin-top: 30px;
  font-size: 0.9rem;
  color: #777;
}

footer a {
  color: #007aff;
  text-decoration: none;
}

.cell.fire {
  background-image: radial-gradient(circle at center, #ff4d4d 0%, #ff0000 40%, transparent 70%);
  animation: fireGlow 0.8s infinite alternate;
}

@keyframes fireGlow {
  0% {
    box-shadow: 0 0 10px 5px rgba(255, 69, 0, 0.5);
  }

  100% {
    box-shadow: 0 0 20px 10px rgba(255, 0, 0, 0.7);
  }
}