:root {
    --markdown-bg: #e9fcf2;
    --text-color: #333333;
    --heading-color: #1a1a1a;
    --accent-color: #007acc;
    --border-color: #e0e0e0;
    --code-bg: #f5f5f5;
    --blockquote-bg: #f9f9f9;
    --blockquote-border: #ccc;
}

/* --- 主内容区基础样式 --- */
.markdown-body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Helvetica, Arial, sans-serif, "Apple Color Emoji", "Segoe UI Emoji";
    font-size: 16px;
    line-height: 1.7;
    color: var(--text-color);
    background-color: var(--markdown-bg);
    padding: 40px;
    border-radius: 8px;
    max-width: 95vw;
}

/* --- 标题排版 --- */
.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: 1.25;
    color: var(--heading-color);
    border-bottom: 1px solid var(--border-color);
    padding-bottom: 0.3em;
}

.markdown-body h1 { font-size: 2.25em; }
.markdown-body h2 { font-size: 1.75em; }
.markdown-body h3 { font-size: 1.5em; }
.markdown-body h4 { font-size: 1.25em; }

/* --- 段落与链接 --- */
.markdown-body p {
    margin-top: 0;
    margin-bottom: 16px;
}

.markdown-body a {
    color: var(--accent-color);
    text-decoration: none;
    transition: color 0.2s ease-in-out;
}

.markdown-body a:hover {
    text-decoration: underline;
}

/* --- 列表 --- */
.markdown-body ul,
.markdown-body ol {
    padding-left: 2em;
    margin-bottom: 16px;
}

/* --- 引用块 --- */
.markdown-body blockquote {
    margin: 0 0 16px 0;
    padding: 10px 20px;
    font-size: 1em;
    color: #b0b0b0;
    border-left: 0.25em solid var(--blockquote-border);
    background-color: var(--blockquote-bg);
}

/* --- 代码 --- */
/* 行内代码 */
.markdown-body :not(pre) > code {
    font-family: "SFMono-Regular", Consolas, "Liberation Mono", Menlo, monospace;
    font-size: 0.875em;
    background-color: var(--code-bg);
    color: var(--text-color);
    padding: 0.2em 0.4em;
    border-radius: 6px;
}

/* 代码块 */
.markdown-body pre {
    padding: 16px;
    overflow: auto;
    font-size: 0.9em;
    line-height: 1.45;
    background-color: #1c2128; /* 配合 highlight.js github-dark 主题 */
    border-radius: 6px;
    margin-bottom: 16px;
    max-width: 70vw;
}

.markdown-body pre code {
    padding: 0;
    margin: 0;
    background-color: transparent;
    border: 0;
}

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

.markdown-body pre::-webkit-scrollbar-track {
    background: rgba(0,0,0,0.1);
    border-radius: 4px;
}

.markdown-body pre::-webkit-scrollbar-thumb {
    background: #4a5568;
    border-radius: 4px;
    border: 2px solid transparent;
    background-clip: content-box;
}

.markdown-body pre::-webkit-scrollbar-thumb:hover {
    background: #2d3748;
}

.markdown-body pre {
    scrollbar-width: thin;
    scrollbar-color: #4a5568 rgba(0,0,0,0.1);
}

/* --- 表格 --- */
.markdown-body table {
    width: 100%;
    border-collapse: collapse;
    margin-bottom: 16px;
    display: block;
    overflow: auto;
}

.markdown-body th,
.markdown-body td {
    padding: 12px 15px;
    border: 1px solid var(--border-color);
}

.markdown-body th {
    background-color: var(--code-bg);
    font-weight: 600;
}

.markdown-body tr:nth-child(2n) {
    background-color: var(--blockquote-bg);
}

/* --- 图片 --- */
.markdown-body img {
    max-width: 100%;
    height: auto;
    display: block;
    margin: 16px auto;
    border-radius: 8px;
    box-shadow: 0 4px 12px rgba(0,0,0,0.1);
}


/* --- 数学公式 (KaTeX) --- */
.markdown-body .katex-display {
    overflow-x: auto;
    overflow-y: hidden;
    padding: 8px 0;
}
.markdown-body .katex {
    font-size: 1.1em; /* 使公式字体比正文稍大，更清晰 */
}


/* --- TOC (Table of Contents) 动态目录样式 --- */

/* 1. 外层悬停触发区域 */
#toc-wrapper {
    position: fixed;
    top: 0;
    right: 0;
    height: 100%;
    width: 280px; /* 容器宽度 = TOC宽度 + 触发区宽度 */
    z-index: 1000;
    /* 通过 transform 将实际内容区移出屏幕，仅留出一小部分触发区 */
    transform: translateX(260px); 
    transition: transform 0.4s ease;
}

/* 2. TOC 实际内容容器 */
#toc-container {
    width: 260px; /* TOC 宽度 */
    height: 100%;
    padding: 20px;
    padding-top: 80px; /* 留出顶部空间 */
    background-color: var(--markdown-bg);
    border-left: 1px solid var(--border-color);
    box-shadow: -5px 0 15px rgba(0,0,0,0.1);
    overflow-y: auto;
}

/* 3. 核心：当鼠标悬停在外层容器上时，将其移回屏幕内 */
#toc-wrapper:hover {
    transform: translateX(0);
}


/* TOC 内部样式 (与之前类似，稍作调整) */
.toc-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 15px;
}

.toc-header h3 {
    margin: 0;
    font-size: 1.2em;
    color: var(--heading-color);
}

#toc-container ul {
    list-style: none;
    padding: 0;
    margin: 0;
}

/* h2 级别的列表项 */
#toc-container .toc-h2 > a {
    font-weight: bold;
}

#toc-container .toc-h2 .toggle-icon {
    cursor: pointer;
    display: inline-block;
    padding: 0 8px;
    font-style: normal;
    transition: transform 0.2s;
    user-select: none; /* 防止双击选中文本 */
}

#toc-container .toc-h2 .toggle-icon.collapsed {
    transform: rotate(-90deg);
}

/* h3 级别的子列表 */
#toc-container .toc-h2 ul {
    padding-left: 20px;
    display: block;
}

#toc-container .toc-h2 ul.collapsed {
    display: none;
}

#toc-container li a {
    display: inline-block;
    padding: 6px 0;
    font-size: 0.9em;
    color: var(--text-color);
    text-decoration: none;
    transition: color 0.2s;
}

#toc-container li a:hover {
    color: var(--accent-color);
}

#toc-container li a.active {
    color: var(--accent-color);
    font-weight: bold;
}