body {
    font-family: Arial, sans-serif;
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    background-color: #f4f4f9;
    margin: 0;
}

.container {
    background-color: white;
    padding: 30px;
    border-radius: 8px;
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.1);
    text-align: center;
    width: 350px;
}

h1 {
    color: #333;
}

.input-group {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 15px;
}

.input-group label {
    font-size: 16px;
    color: #555;
    flex-basis: 30%;
    text-align: left;
}

.input-group input[type="number"] {
    flex-basis: 65%;
    padding: 8px;
    border: 1px solid #ddd;
    border-radius: 4px;
    font-size: 16px;
    text-align: right;
}

.option-group {
    display: flex;
    align-items: center;
    margin-bottom: 15px;
}

.option-group input[type="checkbox"] {
    width: 20px;
    height: 20px;
    margin-right: 10px;
}

.option-group label {
    font-size: 16px;
    color: #555;
    user-select: none;
}

#generateButton {
    width: 100%;
    padding: 12px;
    border: none;
    border-radius: 4px;
    background-color: #007bff;
    color: white;
    font-size: 18px;
    cursor: pointer;
    margin-top: 10px;
}

#generateButton:hover {
    background-color: #0056b3;
}

.result-container {
    margin-top: 30px;
    text-align: left;
}

#resultArea {
    padding: 10px;
    background-color: #eee;
    border: 1px solid #ccc;
    border-radius: 4px;
    min-height: 50px;
    white-space: pre-wrap;
    font-size: 16px;
    line-height: 1.5;
}

/* TOPに戻るボタンのスタイル */
.return-top-group {
    margin-top: 20px;
    text-align: center;
}

.return-button {
    display: block; /* ブロック要素にして幅を100%にする */
    width: 100%; /* 親要素の幅いっぱいに広げる */
    padding: 12px;
    background-color: #6c757d; /* 読み込みボタンと同じ色に */
    color: white;
    text-decoration: none;
    border-radius: 4px;
    font-size: 18px;
    transition: background-color 0.2s;
    box-sizing: border-box; /* paddingを含めて幅を計算する */
}

.return-button:hover {
    background-color: #5a6268;
}