body {
    font-family: 'MS PMincho', 'MS Mincho', serif;
    background-color: #e8e6e1;
    color: #3a3a3a;
    line-height: 2.0;
}
.container {
    max-width: 800px;
    margin: 20px auto;
    background-color: #fdfdfa; /* 少し明るい紙の色に */
    border: 1px solid #ccc;
    box-shadow: 0 0 15px rgba(0,0,0,0.1);
    padding: 20px 40px;
}
header {
    text-align: center;
    border-bottom: 2px dashed #8b7d6b;
    margin-bottom: 30px;
    padding-bottom: 20px;
}
header h1 {
    font-size: 2.5em;
    color: #4a4339;
}
.subtitle {
    font-size: 1.1em;
    color: #6c6155;
    font-style: italic; /* サブタイトルをイタリックに */
}
section {
    margin-bottom: 40px;
}
h2 {
    font-size: 1.8em;
    color: #fff;
    background-color: #8b7d6b;
    padding: 10px 20px;
    border-radius: 5px;
    text-align: center;
    box-shadow: 2px 2px 5px rgba(0,0,0,0.2);
}
p {
    font-size: 1.1em;
}
/* 強調表示ブロック */
.emphasis {
    font-weight: bold;
    text-align: center;
    background-color: #fffacd;
    padding: 15px;
    border: 1px solid #f0e68c;
    margin: 20px 0;
}
/* マニュアル表示用のスタイル */
.manual {
    background-color: #f5f5f5;
    border: 1px solid #ddd;
    padding: 5px 20px;
    margin: 20px 0;
    border-left: 5px solid #a09a8d;
}
.manual h4 {
    margin-bottom: 10px;
    text-decoration: underline;
}
.manual ol li {
    margin-bottom: 10px;
}

.image-container {
    text-align: center;
    margin-top: 20px;
}
.image-container img {
    max-width: 100%;
    height: auto;
    border: 5px solid #c3b8a5;
}
.caption {
    font-style: italic;
    color: #555;
    margin-top: 10px;
}
#action-area {
    background-color: #f5f2ed;
    border: 1px solid #ddd;
    padding: 20px;
    text-align: center;
}
#action-area h3 {
    font-size: 1.5em;
    margin-top: 0;
}
#password {
    padding: 10px;
    font-size: 1.2em;
    width: 150px;
    text-align: center;
}
button {
    padding: 10px 20px;
    font-size: 1.2em;
    background-color: #607d8b;
    color: #fff;
    border: none;
    cursor: pointer;
    transition: background-color 0.3s;
}
button:hover {
    background-color: #455a64;
}
#message {
    color: #d32f2f;
    font-weight: bold;
}
#result p {
    font-size: 1.2em;
}
.next-stage {
    display: inline-block;
    margin-top: 15px;
    padding: 10px 20px;
    font-size: 1.5em;
    font-weight: bold;
    color: #fff;
    background-color: #333;
    text-decoration: none;
}
footer {
    text-align: center;
    margin-top: 30px;
    padding-top: 20px;
    border-top: 1px solid #ddd;
    font-size: 0.9em;
    color: #777;
}