/* Base styles and variables */
:root {
  --primary-color: #3498db;
  --secondary-color: #e74c3c;
  --background-color: #f9f9f9;
  --cell-bg-color: #ffffff;
  --text-color: #333333;
  --border-color: #e0e0e0;
  --shadow-color: rgba(0, 0, 0, 0.1);
  --hover-color: #f0f0f0;
  --x-color: #3498db;
  --o-color: #e74c3c;
}

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

body {
  font-family: "Segoe UI", Tahoma, Geneva, Verdana, sans-serif;
  background-color: var(--background-color);
  color: var(--text-color);
  line-height: 1.6;
}

.container {
  max-width: 800px;
  margin: 0 auto;
  padding: 20px;
}

/* Header styles */
header {
  text-align: center;
  margin-bottom: 30px;
}

h1 {
  font-size: 2.5rem;
  color: var(--primary-color);
  margin-bottom: 5px;
}

.subtitle {
  font-size: 1.1rem;
  color: #666;
}

/* Game container */
.game-container {
  background-color: var(--cell-bg-color);
  border-radius: 10px;
  padding: 20px;
  box-shadow: 0 4px 15px var(--shadow-color);
  margin-bottom: 30px;
}

.status-message {
  text-align: center;
  font-size: 1.2rem;
  font-weight: 600;
  margin-bottom: 20px;
  height: 30px;
  color: var(--text-color);
}

/* Game board */
.game-board {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  grid-gap: 10px;
  margin-bottom: 20px;
}

.cell-form {
  width: 100%;
  aspect-ratio: 1 / 1;
}

.cell {
  width: 100%;
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 2.5rem;
  font-weight: bold;
  background-color: var(--cell-bg-color);
  border: 2px solid var(--border-color);
  border-radius: 8px;
  cursor: pointer;
  transition: all 0.2s ease;
}

.cell:hover:not([disabled]) {
  background-color: var(--hover-color);
  transform: scale(1.02);
}

.cell:focus {
  outline: none;
  box-shadow: 0 0 0 3px rgba(52, 152, 219, 0.3);
}

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

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

/* Controls */
.controls {
  display: flex;
  justify-content: center;
  margin-top: 20px;
}

.reset-button {
  background-color: var(--primary-color);
  color: white;
  border: none;
  padding: 10px 20px;
  font-size: 1rem;
  border-radius: 5px;
  cursor: pointer;
  transition: background-color 0.2s ease;
}

.reset-button:hover {
  background-color: #2980b9;
}

/* Game info section */
.game-info {
  background-color: var(--cell-bg-color);
  border-radius: 10px;
  padding: 20px;
  box-shadow: 0 4px 15px var(--shadow-color);
}

.game-info h2 {
  color: var(--primary-color);
  margin-bottom: 15px;
}

.game-info ol {
  padding-left: 20px;
}

.game-info li {
  margin-bottom: 10px;
}

/* Footer */
footer {
  text-align: center;
  margin-top: 30px;
  padding-top: 20px;
  border-top: 1px solid var(--border-color);
  color: #666;
}

/* Responsive design */
@media (max-width: 600px) {
  .container {
    padding: 10px;
  }

  h1 {
    font-size: 2rem;
  }

  .cell {
    font-size: 2rem;
  }

  .game-info {
    font-size: 0.9rem;
  }
}

/* Animations */
@keyframes pulse {
  0% {
    transform: scale(1);
  }
  50% {
    transform: scale(1.05);
  }
  100% {
    transform: scale(1);
  }
}

.game-board .cell:active {
  transform: scale(0.95);
}