body {
    font-family: Arial, sans-serif;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    height: 100vh;
    margin: 10;
    background-color: #f0f0f0;
    position: relative;
}

.radio-buttons {
    position: absolute;
    top: 10px;
    left: 10px;
    display: flex;
    flex-direction: column;
}

.periodic-table {
    display: grid;
    grid-template-columns: repeat(8, 50px);
    grid-template-rows: repeat(7, 50px);
    gap: 50px;
}

.element {
    width: 100px;
    height: 100px;
    background-color: #fff;
    border: 1px solid #ccc;
    display: flex;
    justify-content: center;
    align-items: center;
    text-align: center;
    font-size: 44px;
    cursor: pointer;
}

.element:hover {
    background-color: #e0e0e0;
}

.target-element {
    font-size: 80px;
    margin-bottom: 20px;
    color: white;
    text-shadow: -2px -2px 0 #000, 2px -2px 0 #000, -2px 2px 0 #000, 2px 2px 0 #000;
    cursor: pointer;
}

.good-job {
    font-size: 44px;
    color: green;
}

.correct {
    color: blue;
}

.incorrect {
    color: red;
}

.radio-group {
    margin-bottom: 20px;
}

.start-button {
    padding: 10px 20px;
    font-size: 16px;
    cursor: pointer;
    background-color: #4CAF50;
    color: white;
    border: none;
    border-radius: 5px;
}

.start-button:hover {
    background-color: #45a049;
}

#timer {
    font-size: 44px;
    margin-bottom: 20px;
}

/* スマホなどの小さい画面向けのスタイル */
@media (max-width: 600px) {
    .periodic-table {
        grid-template-columns: repeat(4, 40px);
        grid-template-rows: repeat(5, 40px);
        gap: 10px;
    }

    .element {
        width: 40px;
        height: 40px;
        font-size: 20px;
    }

    .target-element {
        font-size: 24px;
    }

    .good-job {
        font-size: 24px;
    }

    .start-button {
        font-size: 14px;
    }
}