body {
    font-family: Arial, sans-serif;
    text-align: center;
    background-color: #d3f0ff;
}

a {text-decoration: none;}

h1 {
    color: #333;
}

.start {
	height: 30px;
	border-radius: 16px;
	background-color: white;
	border: ;
	font-family: 'Trebuchet MS', sans-serif;
}

#game-board {
    display: grid;
    gap: 10px;
    justify-content: center;
    margin: 20px auto;
    perspective: 1000px;
}

.card {
    width: 80px;
    height: 80px;
    background-color: #2a9d8f;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 2rem;
    color: white;
    cursor: pointer;
    border-radius: 10px;
    user-select: none;
    transform-style: preserve-3d;
    transition: transform 0.5s;
}

.card .front, .card .back {
    position: absolute;
    width: 100%;
    height: 100%;
    backface-visibility: hidden;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 10px;
}

.card .front {
    background-color: #ffffff;
    transform: rotateY(180deg);
}

.card .back {
    background-color: #00ffaa;
}

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