body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    background-color: #f0f8ff; /* AliceBlue */
    color: #333;
    margin: 0;
}

.game-container {
    text-align: center;
    background-color: #ffffff;
    padding: 30px;
    border-radius: 15px;
    box-shadow: 0 10px 25px rgba(0, 0, 0, 0.1);
    width: 90%;
    max-width: 700px;
}

h1 {
    color: #0056b3; /* Darker Blue */
    margin-bottom: 20px;
}

#instructions p, #gameInfo p, #winScreen p {
    font-size: 1.1em;
    margin-bottom: 15px;
}

button {
    padding: 12px 25px;
    font-size: 1em;
    color: white;
    background-color: #28a745; /* Green */
    border: none;
    border-radius: 8px;
    cursor: pointer;
    transition: background-color 0.3s ease, transform 0.2s ease;
    margin: 5px;
}

button:hover {
    background-color: #218838; /* Darker Green */
    transform: translateY(-2px);
}

#startButton {
    background-color: #007bff; /* Blue */
}

#startButton:hover {
    background-color: #0056b3; /* Darker Blue */
}

#restartButton {
    background-color: #ffc107; /* Yellow */
    color: #333;
}

#restartButton:hover {
    background-color: #e0a800; /* Darker Yellow */
}

.hidden {
    display: none;
}

#gameArea {
    margin-top: 20px;
}

#cardGrid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(100px, 1fr));
    gap: 15px;
    margin-top: 20px;
    justify-items: center;
    align-items: center;
}

.card {
    width: 100px;
    height: 130px;
    perspective: 1000px;
    cursor: pointer;
    border-radius: 8px;
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.1);
    transition: transform 0.6s;
    transform-style: preserve-3d;
    background-color: #e0e0e0; /* Light Gray for back */
    display: flex;
    justify-content: center;
    align-items: center;
    font-size: 1.5em; /* For emoji */
    font-weight: bold;
    position: relative;
}

.card.flipped {
    transform: rotateY(180deg);
}

.card .face {
    position: absolute;
    width: 100%;
    height: 100%;
    backface-visibility: hidden;
    display: flex;
    justify-content: center;
    align-items: center;
    border-radius: 8px;
    box-shadow: inset 0 0 10px rgba(0, 0, 0, 0.2);
}

.card .front {
    background-color: #ffffff; /* White for front */
    color: #333;
    transform: rotateY(180deg);
    font-size: 0.8em;
    padding: 10px;
    box-sizing: border-box;
    overflow: hidden;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
}

.card .back {
    background-color: #007bff; /* Blue for back */
    color: white;
    transform: rotateY(0deg);
    font-size: 2em; /* Larger for emoji */
}

.card.matched {
    opacity: 0.7;
    box-shadow: 0 0 15px rgba(40, 167, 69, 0.7); /* Green glow */
    background-color: #d4edda; /* Light Green */
}

.card.matched .front {
    background-color: #d4edda;
}

.card.matched .back {
    background-color: #28a745; /* Green */
}

#winScreen {
    margin-top: 30px;
    padding: 20px;
    background-color: #d4edda; /* Light Green */
    border: 2px solid #28a745; /* Green */
    border-radius: 10px;
}

#winScreen h2 {
    color: #28a745;
    margin-bottom: 10px;
}

@media (max-width: 600px) {
    .game-container {
        padding: 20px;
    }
    #cardGrid {
        grid-template-columns: repeat(auto-fill, minmax(80px, 1fr));
        gap: 10px;
    }
    .card {
        width: 80px;
        height: 110px;
    }
    h1 {
        font-size: 1.8em;
    }
    button {
        padding: 10px 20px;
        font-size: 0.9em;
    }
}