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

body {
    font-family: Arial, sans-serif;
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    background-color: #f0f0f0;
}

.container {
    text-align: center;
    padding: 20px;
    background-color: white;
    border-radius: 10px;
    box-shadow: 0 0 10px rgba(0,0,0,0.1);
}

h1 {
    color: #333;
    margin-bottom: 20px;
}

h2 {
    color: #444;
    margin-bottom: 20px;
}

.selection-screen {
    margin: 20px 0;
}

.symbol-buttons {
    display: flex;
    gap: 20px;
    justify-content: center;
    margin-bottom: 20px;
}

.symbol-btn {
    padding: 15px 30px;
    font-size: 1.2em;
    background-color: #4CAF50;
    color: white;
    border: none;
    border-radius: 5px;
    cursor: pointer;
    transition: all 0.3s ease;
}

.symbol-btn:hover {
    background-color: #45a049;
    transform: scale(1.05);
}

.status {
    margin-bottom: 20px;
    font-size: 1.2em;
    color: #666;
}

.game-board {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 10px;
    margin-bottom: 20px;
    max-width: 300px;
    margin-left: auto;
    margin-right: auto;
}

.cell {
    background-color: white;
    border: 2px solid #333;
    aspect-ratio: 1;
    display: flex;
    justify-content: center;
    align-items: center;
    font-size: 2em;
    cursor: pointer;
    transition: background-color 0.3s;
}

.cell:hover {
    background-color: #f5f5f5;
}

.controls {
    display: flex;
    gap: 10px;
    justify-content: center;
}

button {
    padding: 10px 20px;
    font-size: 1em;
    background-color: #4CAF50;
    color: white;
    border: none;
    border-radius: 5px;
    cursor: pointer;
    transition: background-color 0.3s;
}

button:hover {
    background-color: #45a049;
}

.cell.x {
    color: #e74c3c;
}

.cell.o {
    color: #3498db;
}

.hidden {
    display: none;
}

#changeSymbolBtn {
    background-color: #3498db;
}

#changeSymbolBtn:hover {
    background-color: #2980b9;
}

.thinking {
    opacity: 0.7;
    pointer-events: none;
}