* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --primary: #6366F1;
    --secondary: #8B5CF6;
    --bg-light: #FFFFFF;
    --bg-card: #F9FAFB;
    --bg-card-hover: #F3F4F6;
    --text-primary: #111827;
    --text-secondary: #6B7280;
    --border: #E5E7EB;
    --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
}

body {
    font-family: 'Noto Sans SC', -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', sans-serif;
    line-height: 1.8;
    color: var(--text-primary);
    background-color: var(--bg-card);
    padding: 0;
    min-height: 100vh;
}

/* 返回按钮 */
.back-btn {
    position: fixed;
    top: 20px;
    left: 20px;
    z-index: 1000;
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 12px 20px;
    background: var(--bg-light);
    color: var(--text-primary);
    text-decoration: none;
    border-radius: 12px;
    font-weight: 500;
    font-size: 0.95rem;
    border: 1px solid var(--border);
    box-shadow: var(--shadow);
    transition: all 0.3s ease;
}

.back-btn:hover {
    background: var(--bg-card-hover);
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

.back-btn svg {
    width: 20px;
    height: 20px;
}

/* 头部 */
header {
    text-align: center;
    margin: 0;
    padding: 80px 20px 60px;
    background: var(--primary);
    color: white;
}

header h1 {
    font-size: clamp(1.8rem, 5vw, 2.5rem);
    margin-bottom: 16px;
    font-weight: 700;
    line-height: 1.3;
}

header time {
    font-size: 0.95rem;
    opacity: 0.9;
}

/* 主要内容 */
main {
    max-width: 800px;
    margin: -40px auto 0;
    padding: 0 20px 40px;
    position: relative;
    z-index: 1;
}

article {
    background: var(--bg-light);
    padding: 48px 40px;
    border-radius: 16px;
    box-shadow: var(--shadow-lg);
    border: 1px solid var(--border);
}

section {
    margin-bottom: 36px;
}

section:last-child {
    margin-bottom: 0;
}

section h2 {
    font-size: 1.5rem;
    color: var(--primary);
    margin-bottom: 16px;
    padding-bottom: 12px;
    border-bottom: 2px solid var(--border);
    font-weight: 600;
}

section p {
    margin-bottom: 16px;
    text-align: justify;
    text-indent: 2em;
    color: var(--text-primary);
    line-height: 1.9;
}

section p:last-child {
    margin-bottom: 0;
}

/* 作者介绍 */
.author-intro {
    background: var(--bg-card);
    padding: 32px;
    border-radius: 12px;
    margin-top: 48px;
    border: 1px solid var(--border);
}

.author-intro h2 {
    color: var(--text-primary);
    border-bottom-color: var(--border);
}

.author-intro p {
    text-indent: 2em;
    margin-bottom: 12px;
}

.author-intro p:last-child {
    margin-bottom: 0;
}

.qrcode {
    display: block;
    margin: 24px auto 0;
    max-width: 180px;
    border-radius: 12px;
    box-shadow: var(--shadow);
}

/* 页脚 */
footer {
    text-align: center;
    margin-top: 40px;
    padding: 24px 20px;
    color: var(--text-secondary);
    font-size: 0.9rem;
}

/* 响应式设计 */
@media (max-width: 768px) {
    .back-btn {
        top: 10px;
        left: 10px;
        padding: 10px 16px;
        font-size: 0.9rem;
    }
    
    header {
        padding: 70px 16px 50px;
    }
    
    main {
        padding: 0 16px 32px;
    }
    
    article {
        padding: 32px 24px;
    }
    
    section h2 {
        font-size: 1.3rem;
    }
    
    .author-intro {
        padding: 24px;
    }
}