body {
    font-family: Arial, sans-serif;
    text-align: center;
    margin-top: 30px;
}
#game-area {
    width: 80vw;
    height: 60vh;
    border: 2px solid #ccc;
    margin: 20px auto;
    position: relative;
    background-color: #f9f9f9;
}
.circle {
    width: 50px;
    height: 50px;
    background-color: red;
    border-radius: 50%;
    position: absolute;
    cursor: pointer;
    box-shadow: 0 0 10px rgba(0,0,0,0.3);
}