:root {
    --bg-color: #fff;
    --text-color: #000;
    --card-bg: #ccc;
}

body {
    background-color: var(--bg-color);
    color: var(--text-color);
    font-family: Arial, sans-serif;
}

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

.game-grid {
    display: grid;
    gap: 10px;
    margin-top: 20px;
}

.card {
    background-color: var(--card-bg);
    border-radius: 10px;
    cursor: pointer;
    background-size: cover;
    background-position: center;
    width: 100px;
    height: 100px;
}

#timer {
    margin-top: 20px;
    font-size: 1.2em;
}

#dark-mode-toggle {
    margin-top: 20px;
}

.dark-mode {
    --bg-color: #333;
    --text-color: #fff;
    --card-bg: #555;
}