body {
    margin: 0;
    font-family: Arial, Helvetica, sans-serif;
    background: #fff;
    color: #111;
    display: flex;
    font-weight: bold;
    justify-content: center;
    align-items: center;
    height: 100vh;
}

.container {
    text-align: center;
}

.box {
    width: 200px;
    height: 200px;
    margin: 30px auto;
    background: gray;
    display: none;
}

.info {
    font-size: 18px;
    margin-top: 10px;
}

.result {
    margin-top: 15px;
    font-weight: bold;
}