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

body {
    font-family: Arial, sans-serif;
    background: linear-gradient(135deg, #1a1a2e, #16213e);
    color: #fff;
    min-height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
}

.container {
    text-align: center;
}

h1 {
    margin-bottom: 2rem;
    font-size: 3rem;
    text-shadow: 0 0 10px rgba(255, 255, 255, 0.5);
}

.status {
    font-size: 1.5rem;
    margin-bottom: 2rem;
    opacity: 0.9;
}

.board {
    display: grid;
    grid-template-columns: repeat(3, 100px);
    gap: 10px;
    margin: 0 auto;
    max-width: 320px;
}

.cell {
    background: rgba(255, 255, 255, 0.1);
    border-radius: 10px;
    height: 100px;
    cursor: pointer;
    display: flex;
    justify-content: center;
    align-items: center;
    font-size: 3rem;
    transition: all 0.3s ease;
}

.cell:hover {
    background: rgba(255, 255, 255, 0.2);
    transform: scale(1.05);
}

.cell.x::before {
    content: "X";
    color: #00ff88;
    animation: popIn 0.4s cubic-bezier(0.68, -0.55, 0.265, 1.55);
}

.cell.o::before {
    content: "O";
    color: #ff3366;
    animation: popIn 0.4s cubic-bezier(0.68, -0.55, 0.265, 1.55);
}

@keyframes popIn {
    0% {
        transform: scale(0);
        opacity: 0;
    }
    100% {
        transform: scale(1);
        opacity: 1;
    }
}

.cell.win {
    background: rgba(0, 255, 136, 0.3);
    animation: pulse 1s infinite;
}

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

#restartButton {
    margin-top: 2rem;
    padding: 1rem 2rem;
    font-size: 1.2rem;
    background: rgba(255, 255, 255, 0.1);
    border: none;
    color: white;
    border-radius: 5px;
    cursor: pointer;
    transition: all 0.3s ease;
}

#restartButton:hover {
    background: rgba(255, 255, 255, 0.2);
    transform: scale(1.05);
}

.sound-controls {
    margin-top: 1rem;
    font-size: 1rem;
    opacity: 0.8;
}

.sound-controls label {
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
}

.sound-controls input[type="checkbox"] {
    width: 16px;
    height: 16px;
    cursor: pointer;
}

.footer {
    margin-top: 2rem;
    font-size: 1rem;
    opacity: 0.8;
    text-align: center;
}

.author {
    font-weight: bold;
    background: linear-gradient(45deg, #0022ff, #bc103b);
    -webkit-background-clip: text;
    background-clip: text;
    color: transparent;
    animation: gradient 3s ease infinite;
}

@keyframes gradient {
    0% {
        background-position: 0% 50%;
    }
    50% {
        background-position: 100% 50%;
    }
    100% {
        background-position: 0% 50%;
    }
}