/**
 * Markdown Renderer v2.0 - Unified Stylesheet
 * 全站统一的 Markdown 渲染样式
 * 强制 HTML 结构规范、类名统一、CSS 变量驱动
 * 适用于：文章、评论、文档、通知、AI 回复等所有场景
 */

/* =====================================================
 * 根容器 - 所有 Markdown 内容必须包裹在此类下
 * ===================================================== */

.markdown-body {
    font-family: var(--md-font-sans, -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif);
    font-size: var(--md-font-size, 15px);
    line-height: var(--md-line-height, 1.7);
    color: var(--md-text-primary, #1f2937);
    word-wrap: break-word;
    overflow-wrap: break-word;
    max-width: 100%;
}

.markdown-body * {
    box-sizing: border-box;
}

/* =====================================================
 * 标题样式 - H1-H6 层级清晰、间距合理
 * ===================================================== */

.markdown-body h1,
.markdown-body h2,
.markdown-body h3,
.markdown-body h4,
.markdown-body h5,
.markdown-body h6 {
    margin-top: 24px;
    margin-bottom: 16px;
    font-weight: 600;
    line-height: 1.4;
    position: relative;
    scroll-margin-top: 80px;
}

.markdown-body h1 {
    font-size: 2em;
    padding-bottom: 0.3em;
    border-bottom: 1px solid var(--md-border, #e5e7eb);
    color: var(--md-text-primary);
}

.markdown-body h2 {
    font-size: 1.5em;
    padding-bottom: 0.3em;
    border-bottom: 1px solid var(--md-border-light, #f3f4f6);
}

.markdown-body h3 {
    font-size: 1.25em;
}

.markdown-body h4 {
    font-size: 1em;
}

.markdown-body h5 {
    font-size: 0.875em;
}

.markdown-body h6 {
    font-size: 0.85em;
    color: var(--md-text-secondary);
}

/* 标题锚点链接 */
.markdown-body .heading-anchor {
    display: none;
    position: absolute;
    left: -1.2em;
    top: 50%;
    transform: translateY(-50%);
    width: 20px;
    height: 20px;
    color: var(--md-text-muted);
    text-decoration: none;
    font-weight: normal;
    opacity: 0;
    transition: opacity 0.2s, color 0.2s;
    text-align: center;
    line-height: 20px;
}

.markdown-body h1:hover .heading-anchor,
.markdown-body h2:hover .heading-anchor,
.markdown-body h3:hover .heading-anchor,
.markdown-body h4:hover .heading-anchor,
.markdown-body h5:hover .heading-anchor,
.markdown-body h6:hover .heading-anchor {
    display: inline-block;
    opacity: 1;
}

.markdown-body .heading-anchor:hover {
    color: var(--md-primary);
}

/* =====================================================
 * 段落样式 - 行高舒适、段间距合理
 * ===================================================== */

.markdown-body p {
    margin-top: 0;
    margin-bottom: 16px;
    line-height: 1.7;
}

/* =====================================================
 * 列表样式 - 缩进一致、符号规范、嵌套清晰
 * ===================================================== */

.markdown-body ul,
.markdown-body ol {
    margin-top: 0;
    margin-bottom: 16px;
    padding-left: 2em;
}

.markdown-body li {
    margin-top: 0.25em;
    list-style-position: outside;
}

.markdown-body ul ul,
.markdown-body ul ol,
.markdown-body ol ol,
.markdown-body ol ul {
    margin-top: 4px;
    margin-bottom: 0;
}

.markdown-body li > p {
    margin-top: 16px;
}

.markdown-body li + li {
    margin-top: 0.25em;
}

/* 任务列表 */
.markdown-body .task-list-item {
    list-style-type: none;
    display: flex;
    align-items: flex-start;
    gap: 8px;
    margin-left: -1.5em;
}

.markdown-body .task-list-item input[type="checkbox"] {
    margin-top: 0.35em;
    width: 16px;
    height: 16px;
    cursor: pointer;
    accent-color: var(--md-primary, #1677ff);
    flex-shrink: 0;
}

.markdown-body .task-list-item label {
    flex: 1;
    cursor: pointer;
}

/* =====================================================
 * 引用样式 - 左侧竖线、背景浅色、可嵌套
 * ===================================================== */

.markdown-body blockquote {
    margin: 0 0 16px 0;
    padding: 12px 16px;
    border-left: 4px solid var(--md-blockquote-border, #1677ff);
    background: var(--md-blockquote-bg, #f9fafb);
    border-radius: 0 var(--md-radius-sm) var(--md-radius-sm) 0;
    color: var(--md-text-secondary);
}

.markdown-body blockquote > :first-child {
    margin-top: 0;
}

.markdown-body blockquote > :last-child {
    margin-bottom: 0;
}

.markdown-body blockquote blockquote {
    margin-top: 8px;
    background: transparent;
}

/* =====================================================
 * 分割线样式
 * ===================================================== */

.markdown-body hr.md-hr,
.markdown-body hr {
    height: 1px;
    margin: 24px 0;
    background-color: var(--md-hr-color, #e5e7eb);
    border: none;
}

/* =====================================================
 * 代码块样式 - 深色背景、语法高亮、复制按钮
 * ===================================================== */

.markdown-body pre {
    margin: 16px 0;
    padding: 0;
    background: var(--md-code-bg, #1e1e1e);
    border-radius: var(--md-radius, 8px);
    overflow-x: auto;
    position: relative;
    font-size: 13px;
    line-height: 1.6;
}

.markdown-body pre.md-code {
    padding: 0;
}

.code-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 8px 16px;
    background: rgba(255, 255, 255, 0.05);
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: var(--md-radius) var(--md-radius) 0 0;
}

.code-lang {
    font-size: 12px;
    color: rgba(255, 255, 255, 0.6);
    text-transform: uppercase;
    font-weight: 500;
}

.code-copy-btn {
    padding: 4px 10px;
    font-size: 12px;
    color: rgba(255, 255, 255, 0.7);
    background: rgba(255, 255, 255, 0.1);
    border: 1px solid rgba(255, 255, 255, 0.15);
    border-radius: var(--md-radius-sm);
    cursor: pointer;
    transition: all 0.2s;
    display: flex;
    align-items: center;
    gap: 4px;
}

.code-copy-btn:hover {
    background: rgba(255, 255, 255, 0.2);
    color: #fff;
}

.code-copy-btn.copied {
    background: var(--md-success, #52c41a);
    color: #fff;
    border-color: var(--md-success);
}

.markdown-body pre code {
    display: block;
    padding: 16px;
    margin: 0;
    font-family: var(--md-font-mono, 'Consolas', monospace);
    font-size: 13px;
    line-height: 1.6;
    color: var(--md-code-text, #d4d4d4);
    background: transparent;
    overflow-x: auto;
    white-space: pre;
    tab-size: 4;
}

/* 行内代码样式 */
.markdown-body code.inline-code,
.markdown-body :not(pre) > code {
    padding: 2px 6px;
    margin: 0 2px;
    font-family: var(--md-font-mono, 'Consolas', monospace);
    font-size: 0.9em;
    background: var(--md-inline-code-bg, #f3f4f6);
    border: 1px solid var(--md-inline-code-border, #e5e7eb);
    border-radius: var(--md-radius-sm);
    color: var(--md-danger, #eb5757);
    word-break: break-word;
}

/* =====================================================
 * 表格样式 - 边框清晰、表头深色、斑马纹、可滚动
 * ===================================================== */

.markdown-body table.md-table,
.markdown-body table {
    width: 100%;
    margin: 16px 0;
    border-collapse: collapse;
    border-spacing: 0;
    overflow: auto;
    display: block;
    max-width: 100%;
    border: 1px solid var(--md-table-border, #e5e7eb);
    border-radius: var(--md-radius);
}

.markdown-body table thead {
    background: var(--md-table-header-bg, #f9fafb);
}

.markdown-body table th,
.markdown-body table td {
    padding: 10px 14px;
    border: 1px solid var(--md-table-border, #e5e7eb);
    text-align: left;
    font-size: 14px;
}

.markdown-body table th {
    font-weight: 600;
    color: var(--md-text-primary);
    background: var(--md-table-header-bg, #f9fafb);
}

.markdown-body table tbody tr:nth-child(2n) {
    background: var(--md-table-stripe, #f9fafb);
}

.markdown-body table tbody tr:hover {
    background: var(--md-primary-light, rgba(22, 119, 255, 0.04));
}

/* =====================================================
 * 链接样式 - 颜色区分、hover 效果、外链图标
 * ===================================================== */

.markdown-body a.md-link,
.markdown-body a {
    color: var(--md-primary, #1677ff);
    text-decoration: none;
    transition: color 0.2s, border-bottom-color 0.2s;
    border-bottom: 1px solid transparent;
}

.markdown-body a:hover {
    color: var(--md-primary-hover, #0958d9);
    border-bottom-color: currentColor;
}

.markdown-body a.external {
    padding-right: 18px;
    position: relative;
}

.markdown-body .external-icon {
    position: absolute;
    right: 0;
    top: 50%;
    transform: translateY(-50%);
    opacity: 0.6;
    transition: opacity 0.2s;
}

.markdown-body a.external:hover .external-icon {
    opacity: 1;
}

/* =====================================================
 * 图片样式 - 自适应、居中、加载占位、点击放大
 * ===================================================== */

.markdown-body img {
    max-width: 100%;
    height: auto;
    box-sizing: content-box;
    background: var(--md-surface, #fafafa);
    border-radius: var(--md-radius-sm);
    border: 1px solid var(--md-border-light, #f3f4f6);
    padding: 4px;
    cursor: pointer;
    transition: transform 0.2s, box-shadow 0.2s;
}

.markdown-body img:hover {
    transform: scale(1.02);
    box-shadow: var(--md-shadow-lg);
}

/* 图片预览遮罩 */
.image-preview-overlay {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.92);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 10000;
    cursor: pointer;
    animation: fadeIn 0.2s ease;
}

.image-preview-container {
    position: relative;
    max-width: 90vw;
    max-height: 90vh;
}

.image-preview-container img {
    max-width: 100%;
    max-height: 90vh;
    object-fit: contain;
    border: none;
    padding: 0;
    border-radius: var(--md-radius);
}

.image-preview-close {
    position: absolute;
    top: -40px;
    right: 0;
    width: 32px;
    height: 32px;
    border: none;
    background: rgba(255, 255, 255, 0.2);
    color: #fff;
    font-size: 28px;
    line-height: 1;
    border-radius: 50%;
    cursor: pointer;
    transition: background 0.2s;
}

.image-preview-close:hover {
    background: rgba(255, 255, 255, 0.3);
}

@keyframes fadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}

/* =====================================================
 * 数学公式样式（KaTeX）
 * ===================================================== */

.markdown-body .md-math.block {
    display: block;
    margin: 24px 0;
    padding: 16px;
    text-align: center;
    overflow-x: auto;
    overflow-y: hidden;
}

.markdown-body .md-math.inline {
    display: inline;
    padding: 0 2px;
}

.markdown-body .md-math.error {
    background: rgba(255, 77, 79, 0.1);
    border: 1px dashed var(--md-danger);
    border-radius: var(--md-radius-sm);
    padding: 4px 8px;
    color: var(--md-danger);
}

/* =====================================================
 * Mermaid 图表样式
 * ===================================================== */

.markdown-body .md-mermaid {
    margin: 24px 0;
    padding: 16px;
    text-align: center;
    background: var(--md-surface, #fafafa);
    border: 1px solid var(--md-border-light, #f3f4f6);
    border-radius: var(--md-radius);
    overflow-x: auto;
}

.markdown-body .md-mermaid svg {
    max-width: 100%;
    height: auto;
}

/* =====================================================
 * 文本格式化样式
 * ===================================================== */

.markdown-body strong {
    font-weight: 600;
    color: var(--md-text-primary);
}

.markdown-body em {
    font-style: italic;
}

.markdown-body del {
    text-decoration: line-through;
    color: var(--md-text-muted);
}

/* =====================================================
 * 错误提示样式
 * ===================================================== */

.markdown-body .parse-error {
    padding: 12px 16px;
    margin: 16px 0;
    background: rgba(255, 77, 79, 0.08);
    border: 1px solid rgba(255, 77, 79, 0.2);
    border-radius: var(--md-radius);
    color: var(--md-danger);
    font-size: 13px;
}

/* =====================================================
 * 滚动条美化
 * ===================================================== */

.markdown-body ::-webkit-scrollbar {
    width: 8px;
    height: 8px;
}

.markdown-body ::-webkit-scrollbar-track {
    background: var(--md-scrollbar-track, #f3f4f6);
    border-radius: 4px;
}

.markdown-body ::-webkit-scrollbar-thumb {
    background: var(--md-scrollbar-thumb, #c4c4c4);
    border-radius: 4px;
    border: 2px solid var(--md-scrollbar-track, #f3f4f6);
}

.markdown-body ::-webkit-scrollbar-thumb:hover {
    background: var(--md-scrollbar-thumb-hover, #a8a8a8);
}

/* =====================================================
 * 响应式适配
 * ===================================================== */

@media (max-width: 768px) {
    .markdown-body {
        font-size: 14px;
        padding: 12px;
    }
    
    .markdown-body h1 {
        font-size: 1.6em;
    }
    
    .markdown-body h2 {
        font-size: 1.35em;
    }
    
    .markdown-body h3 {
        font-size: 1.15em;
    }
    
    .markdown-body pre {
        margin: 12px -12px;
        border-radius: 0;
        font-size: 12px;
    }
    
    .markdown-body pre code {
        padding: 12px;
        font-size: 12px;
    }
    
    .markdown-body table {
        display: block;
        overflow-x: auto;
        white-space: nowrap;
    }
    
    .markdown-body table th,
    .markdown-body table td {
        padding: 8px 10px;
        font-size: 13px;
    }
    
    .markdown-body blockquote {
        margin-left: -12px;
        margin-right: -12px;
        border-radius: 0;
    }
    
    .markdown-body img {
        border-radius: 0;
    }
}

@media (max-width: 480px) {
    .markdown-body {
        font-size: 13px;
        padding: 8px;
    }
    
    .markdown-body ul,
    .markdown-body ol {
        padding-left: 1.5em;
    }
    
    .markdown-body .task-list-item {
        margin-left: -1em;
    }
}