.letter {
    border-top: #c0c0c0 1px solid;
    font-size: 18px;
    line-height: 1.8;
    color: #333;
    font-family: cursive, sans-serif;
    max-width: 1200px;
    margin: 0 auto;
    padding: 2rem;
    text-align: left;
    background-color: #fff;
}

.letter-header {
    text-align: center;
    margin-bottom: 2rem;
}

.letter-header .updated {
    color: #666;
    font-size: 12px;
}

.letter-date {
    color: #666;
    margin-top: 1rem;
}

.letter-content {
    line-height: 1.6;
}

.letter-content p {
    text-indent: 2em;
}

.letter-content p.greeting {
    text-indent: 0em;
}

.greeting {
    margin-bottom: 1.5rem;
}

.salutation {
    margin-bottom: 2rem;
}

h3 {
    color: #108775;
    margin-top: 2rem;
    margin-bottom: 1rem;
}

.closing {
    margin-top: 2rem;
    font-style: italic;
}

.signature {
    margin-top: 3rem;
    text-align: center;
}

.signature p {
    margin: 0;
    text-indent: 0em;
}

.signature .bob-head {
    width: 80px;
    height: 80px;
    margin: 0 auto;
    margin-bottom: 1rem;
}

p {
    margin-block-start: 0.5em;
    margin-block-end: 0.5em;
}

/* 页面特定的样式 */
h2 {
    color: #108775;
}

div.section {
    margin-bottom: 3rem;
}

div.intro {
    font-weight: bold;
    text-align: center;
}

.group-qrcode {
    display: block;
    width: 360px;
    height: auto;
    margin: 2rem auto;
    border-radius: 8px;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
}