diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..ad44091
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,21 @@
+# 构建产物
+/target/
+debug/
+release/
+
+# Cargo
+Cargo.lock
+
+# IDE
+.idea/
+.vscode/
+*.swp
+*.swo
+
+# 系统文件
+.DS_Store
+Thumbs.db
+
+# 临时文件
+*.tmp
+*.log
\ No newline at end of file
diff --git a/Cargo.toml b/Cargo.toml
index 19d9f03..06791cb 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -35,7 +35,7 @@ serde_json = "1.0"
 config = "0.14"
 anyhow = "1.0"
 tracing = "0.1"
-tracing-subscriber = "0.3"
+tracing-subscriber = { version = "0.3", features = ["env-filter"] }
 
 # 工具
 rayon = "1.8"  # 并行计算
diff --git a/assets/style.css b/assets/style.css
new file mode 100644
index 0000000..2837547
--- /dev/null
+++ b/assets/style.css
@@ -0,0 +1,177 @@
+/* ReadFlow 基础样式 */
+
+:root {
+    /* 浅色主题 */
+    --bg-primary: #ffffff;
+    --bg-secondary: #f5f5f5;
+    --bg-tertiary: #e8e8e8;
+    --text-primary: #333333;
+    --text-secondary: #666666;
+    --text-muted: #999999;
+    --border-color: #e0e0e0;
+    --accent-color: #4a90d9;
+    --accent-hover: #3a7bc8;
+    --shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
+}
+
+[data-theme="dark"] {
+    /* 深色主题 */
+    --bg-primary: #1a1a1a;
+    --bg-secondary: #2a2a2a;
+    --bg-tertiary: #3a3a3a;
+    --text-primary: #e0e0e0;
+    --text-secondary: #b0b0b0;
+    --text-muted: #808080;
+    --border-color: #404040;
+    --accent-color: #5a9fe0;
+    --accent-hover: #6aafef;
+    --shadow: 0 2px 8px rgba(0, 0, 0, 0.3);
+}
+
+* {
+    margin: 0;
+    padding: 0;
+    box-sizing: border-box;
+}
+
+body {
+    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
+    font-size: 16px;
+    line-height: 1.6;
+    color: var(--text-primary);
+    background-color: var(--bg-primary);
+}
+
+/* 文档容器 */
+.document {
+    max-width: 800px;
+    margin: 0 auto;
+    padding: 20px;
+}
+
+/* 页面样式 */
+.page {
+    background: var(--bg-primary);
+    border: 1px solid var(--border-color);
+    margin-bottom: 20px;
+    padding: 40px;
+    box-shadow: var(--shadow);
+    min-height: 300px;
+}
+
+.pdf-page {
+    aspect-ratio: 8.5 / 11;
+}
+
+/* 文本内容 */
+.text-page {
+    white-space: pre-wrap;
+    word-wrap: break-word;
+}
+
+/* 代码块 */
+pre, code {
+    font-family: "SF Mono", Monaco, "Courier New", monospace;
+    font-size: 14px;
+    background: var(--bg-secondary);
+    border-radius: 4px;
+}
+
+pre {
+    padding: 16px;
+    overflow-x: auto;
+}
+
+code {
+    padding: 2px 6px;
+}
+
+/* 搜索结果高亮 */
+.highlight {
+    background-color: #ffeb3b;
+    padding: 2px 4px;
+    border-radius: 2px;
+}
+
+[data-theme="dark"] .highlight {
+    background-color: #ffc107;
+}
+
+/* 目录 */
+.toc {
+    background: var(--bg-secondary);
+    padding: 16px;
+    border-radius: 8px;
+    margin-bottom: 20px;
+}
+
+.toc-entry {
+    padding: 8px 0;
+    cursor: pointer;
+    transition: color 0.2s;
+}
+
+.toc-entry:hover {
+    color: var(--accent-color);
+}
+
+.toc-entry.level-1 {
+    font-weight: bold;
+}
+
+.toc-entry.level-2 {
+    padding-left: 20px;
+}
+
+.toc-entry.level-3 {
+    padding-left: 40px;
+}
+
+/* 滚动条 */
+::-webkit-scrollbar {
+    width: 8px;
+    height: 8px;
+}
+
+::-webkit-scrollbar-track {
+    background: var(--bg-secondary);
+}
+
+::-webkit-scrollbar-thumb {
+    background: var(--text-muted);
+    border-radius: 4px;
+}
+
+::-webkit-scrollbar-thumb:hover {
+    background: var(--text-secondary);
+}
+
+/* 主题切换按钮 */
+.theme-toggle {
+    position: fixed;
+    top: 20px;
+    right: 20px;
+    padding: 8px 16px;
+    background: var(--bg-secondary);
+    border: 1px solid var(--border-color);
+    border-radius: 20px;
+    cursor: pointer;
+    font-size: 14px;
+    transition: all 0.2s;
+}
+
+.theme-toggle:hover {
+    background: var(--accent-color);
+    color: white;
+}
+
+/* 响应式 */
+@media (max-width: 768px) {
+    .document {
+        padding: 10px;
+    }
+    
+    .page {
+        padding: 20px;
+    }
+}
\ No newline at end of file
diff --git a/src/core/document.rs b/src/core/document.rs
index 6d13ed0..237d967 100644
--- a/src/core/document.rs
+++ b/src/core/document.rs
@@ -1,22 +1,51 @@
 //! 文档处理引擎
+//! 
+//! 支持 PDF、EPUB、MOBI、TXT、Markdown 等格式
 
-use anyhow::Result;
+use anyhow::{Context, Result};
+use std::path::Path;
 
+#[derive(Debug)]
 pub enum DocumentFormat {
     Pdf,
     Epub,
     Mobi,
     Azw3,
-   Txt,
+    Txt,
     Markdown,
-    Code,
+    Code(String), // 代码语言
 }
 
 pub struct Document {
     pub format: DocumentFormat,
     pub title: String,
     pub path: String,
-    pub content: Vec<u8>,
+    pub metadata: DocumentMetadata,
+    pub pages: Vec<Page>,
+}
+
+#[derive(Debug, Default)]
+pub struct DocumentMetadata {
+    pub author: Option<String>,
+    pub page_count: usize,
+    pub file_size: u64,
+    pub creation_date: Option<String>,
+    pub modification_date: Option<String>,
+}
+
+#[derive(Debug, Clone)]
+pub struct Page {
+    pub number: usize,
+    pub width: f32,
+    pub height: f32,
+    pub content: PageContent,
+}
+
+#[derive(Debug, Clone)]
+pub enum PageContent {
+    Pdf(Vec<u8>),           // PDF 渲染数据
+    Text(String),           // 纯文本内容
+    Html(String),           // HTML 渲染内容
 }
 
 pub struct DocumentEngine;
@@ -26,18 +55,271 @@ impl DocumentEngine {
         Self
     }
     
+    /// 根据文件扩展名判断文档格式
+    fn detect_format(path: &str) -> Option<DocumentFormat> {
+        let path = Path::new(path);
+        let ext = path.extension()?.to_str()?.to_lowercase();
+        
+        match ext.as_str() {
+            "pdf" => Some(DocumentFormat::Pdf),
+            "epub" => Some(DocumentFormat::Epub),
+            "mobi" => Some(DocumentFormat::Mobi),
+            "azw" | "azw3" => Some(DocumentFormat::Azw3),
+            "txt" | "text" => Some(DocumentFormat::Txt),
+            "md" | "markdown" => Some(DocumentFormat::Markdown),
+            "js" | "ts" | "py" | "rs" | "go" | "java" | "c" | "cpp" | "h" | "css" | "html" | "json" | "xml" | "yaml" | "yml" | "toml" | "sql" | "sh" | "bash" | "zsh" => {
+                Some(DocumentFormat::Code(ext))
+            }
+            _ => None,
+        }
+    }
+    
+    /// 打开文档
     pub fn open(&self, path: &str) -> Result<Document> {
-        // 后续实现：基于文件扩展名判断格式并解析
-        todo!("Implement document opening for: {}", path)
+        let format = Self::detect_format(path)
+            .context("Unsupported document format")?;
+        
+        let path_obj = Path::new(path);
+        let title = path_obj
+            .file_stem()
+            .and_then(|s| s.to_str())
+            .unwrap_or("Untitled")
+            .to_string();
+        
+        let metadata = std::fs::metadata(path)
+            .map(|m| DocumentMetadata {
+                file_size: m.len(),
+                ..Default::default()
+            })
+            .unwrap_or_default();
+        
+        // 读取文件内容
+        let content = std::fs::read(path)?;
+        
+        // 根据格式解析文档
+        let pages = match format {
+            DocumentFormat::Pdf => self.parse_pdf(&content)?,
+            DocumentFormat::Epub => self.parse_epub(&content)?,
+            DocumentFormat::Mobi => self.parse_mobi(&content)?,
+            _ => vec![Page {
+                number: 1,
+                width: 612.0,
+                height: 792.0,
+                content: PageContent::Text(String::from_utf8_lossy(&content).to_string()),
+            }],
+        };
+        
+        Ok(Document {
+            format,
+            title,
+            path: path.to_string(),
+            metadata: DocumentMetadata {
+                page_count: pages.len(),
+                ..metadata
+            },
+            pages,
+        })
     }
     
+    /// 解析 PDF 文档
+    fn parse_pdf(&self, content: &[u8]) -> Result<Vec<Page>> {
+        // 使用 pdfium-render 库解析 PDF
+        // 这里简化实现，实际需要更复杂的处理
+        
+        // 创建一个简单的页面列表
+        // 实际实现中，pdfium 会返回每个页面的渲染数据
+        Ok(vec![Page {
+            number: 1,
+            width: 612.0,  // 美国信纸宽度 (8.5" * 72 dpi)
+            height: 792.0, // 美国信纸高度
+            content: PageContent::Pdf(content.to_vec()),
+        }])
+    }
+    
+    /// 解析 EPUB 文档
+    fn parse_epub(&self, content: &[u8]) -> Result<Vec<Page>> {
+        // 使用 epub 库解析
+        // 简化实现
+        Ok(vec![Page {
+            number: 1,
+            width: 612.0,
+            height: 792.0,
+            content: PageContent::Text(String::from_utf8_lossy(content).to_string()),
+        }])
+    }
+    
+    /// 解析 MOBI 文档
+    fn parse_mobi(&self, content: &[u8]) -> Result<Vec<Page>> {
+        // 使用 mobi 库解析
+        Ok(vec![Page {
+            number: 1,
+            width: 600.0,
+            height: 800.0,
+            content: PageContent::Text(String::from_utf8_lossy(content).to_string()),
+        }])
+    }
+    
+    /// 渲染文档为 HTML
     pub fn render(&self, doc: &Document) -> Result<String> {
-        // 后续实现：渲染文档内容
-        todo!("Implement document rendering")
+        let mut html = String::new();
+        
+        html.push_str("<!DOCTYPE html>\n<html>\n<head>\n");
+        html.push_str("<meta charset=\"UTF-8\">\n");
+        html.push_str(&format!("<title>{}</title>\n", doc.title));
+        html.push_str("<style>\n");
+        html.push_str(Self::get_default_css());
+        html.push_str("</style>\n</head>\n<body>\n");
+        html.push_str("<div class=\"document\">\n");
+        
+        for page in &doc.pages {
+            match &page.content {
+                PageContent::Pdf(data) => {
+                    html.push_str(&format!(
+                        "<div class=\"page pdf-page\" data-page=\"{}\">\n",
+                        page.number
+                    ));
+                    // 后续：Base64 编码的 PDF 数据用于嵌入
+                    html.push_str("</div>\n");
+                }
+                PageContent::Text(text) => {
+                    html.push_str(&format!(
+                        "<div class=\"page text-page\" data-page=\"{}\">\n",
+                        page.number
+                    ));
+                    html.push_str(&self.format_text_content(text));
+                    html.push_str("</div>\n");
+                }
+                PageContent::Html(html_content) => {
+                    html.push_str(html_content);
+                }
+            }
+        }
+        
+        html.push_str("</div>\n</body>\n</html>");
+        
+        Ok(html)
     }
     
-    pub fn search(&self, doc: &Document, query: &str) -> Result<Vec<usize>> {
-        // 后续实现：全文搜索
-        todo!("Implement search functionality")
+    /// 获取默认 CSS 样式
+    fn get_default_css() -> &'static str {
+        r#":root {
+    --bg-primary: #ffffff;
+    --bg-secondary: #f5f5f5;
+    --bg-tertiary: #e8e8e8;
+    --text-primary: #333333;
+    --text-secondary: #666666;
+    --text-muted: #999999;
+    --border-color: #e0e0e0;
+    --accent-color: #4a90d9;
+    --accent-hover: #3a7bc8;
+    --shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
+}
+[data-theme="dark"] {
+    --bg-primary: #1a1a1a;
+    --bg-secondary: #2a2a2a;
+    --bg-tertiary: #3a3a3a;
+    --text-primary: #e0e0e0;
+    --text-secondary: #b0b0b0;
+    --text-muted: #808080;
+    --border-color: #404040;
+    --accent-color: #5a9fe0;
+    --accent-hover: #6aafef;
+    --shadow: 0 2px 8px rgba(0, 0, 0, 0.3);
+}
+* { margin: 0; padding: 0; box-sizing: border-box; }
+body {
+    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
+    font-size: 16px;
+    line-height: 1.6;
+    color: var(--text-primary);
+    background-color: var(--bg-primary);
+}
+.document { max-width: 800px; margin: 0 auto; padding: 20px; }
+.page {
+    background: var(--bg-primary);
+    border: 1px solid var(--border-color);
+    margin-bottom: 20px;
+    padding: 40px;
+    box-shadow: var(--shadow);
+    min-height: 300px;
+}
+.text-page { white-space: pre-wrap; word-wrap: break-word; }
+pre, code {
+    font-family: "SF Mono", Monaco, monospace;
+    font-size: 14px;
+    background: var(--bg-secondary);
+    border-radius: 4px;
+}
+pre { padding: 16px; overflow-x: auto; }
+code { padding: 2px 6px; }
+::-webkit-scrollbar { width: 8px; height: 8px; }
+::-webkit-scrollbar-track { background: var(--bg-secondary); }
+::-webkit-scrollbar-thumb { background: var(--text-muted); border-radius: 4px; }
+"#
     }
+    
+    /// 格式化文本内容
+    fn format_text_content(&self, text: &str) -> String {
+        // 转义 HTML 特殊字符
+        let escaped = text
+            .replace('&', "&amp;")
+            .replace('<', "&lt;")
+            .replace('>', "&gt;")
+            .replace('"', "&quot;")
+            .replace('\'', "&#39;");
+        
+        // 保留换行
+        escaped.replace('\n', "<br>\n")
+    }
+    
+    /// 搜索文档内容
+    pub fn search(&self, doc: &Document, query: &str) -> Result<Vec<SearchResult>> {
+        let mut results = Vec::new();
+        let query_lower = query.to_lowercase();
+        
+        for page in &doc.pages {
+            if let PageContent::Text(text) = &page.content {
+                let text_lower = text.to_lowercase();
+                
+                // 简单实现：查找所有匹配位置
+                let mut start = 0;
+                while let Some(pos) = text_lower[start..].find(&query_lower) {
+                    let absolute_pos = start + pos;
+                    let context_start = absolute_pos.saturating_sub(50);
+                    let context_end = (absolute_pos + query.len() + 50).min(text.len());
+                    
+                    results.push(SearchResult {
+                        page: page.number,
+                        position: absolute_pos,
+                        context: text[context_start..context_end].to_string(),
+                    });
+                    
+                    start = absolute_pos + 1;
+                }
+            }
+        }
+        
+        Ok(results)
+    }
+    
+    /// 获取目录结构
+    pub fn get_toc(&self, doc: &Document) -> Result<Vec<TocEntry>> {
+        // 简化实现：返回空目录
+        // 后续可以从 PDF/EPUB 元数据中提取目录
+        Ok(vec![])
+    }
+}
+
+#[derive(Debug, Clone)]
+pub struct SearchResult {
+    pub page: usize,
+    pub position: usize,
+    pub context: String,
+}
+
+#[derive(Debug, Clone)]
+pub struct TocEntry {
+    pub title: String,
+    pub page: usize,
+    pub level: usize,
 }
\ No newline at end of file
diff --git a/src/ui/mod.rs b/src/ui/mod.rs
index 604e4fd..52caf1b 100644
--- a/src/ui/mod.rs
+++ b/src/ui/mod.rs
@@ -1,20 +1,182 @@
 //! UI 模块
 //! 
-//! 使用 Dioxus 构建跨平台 UI
+//! ReadFlow 用户界面
+//! 
+//! 当前版本使用 CLI/TUI 模式，后续可扩展为桌面 GUI
 
 use crate::config::Config;
+use crate::core::document::DocumentEngine;
 
 pub fn run(config: Config) {
-    println!("Starting UI with config: {:?}", config.theme);
+    println!("╔══════════════════════════════════════╗");
+    println!("║         ReadFlow v0.1.0              ║");
+    println!("║    面向开发者的文档阅读工具           ║");
+    println!("╚══════════════════════════════════════╝");
+    println!();
+    println!("主题: {}", config.theme.mode);
+    println!("默认格式: {}", config.reader.default_format);
+    println!("书库路径: {}", config.storage.library_path);
+    println!();
     
-    // 后续实现：Dioxus UI 启动
-    // 示例：
-    // dioxus::launch(App);
+    // 检查命令行参数
+    let args: Vec<String> = std::env::args().collect();
+    
+    if args.len() < 2 {
+        print_help();
+        return;
+    }
+    
+    let command = &args[1];
+    
+    match command.as_str() {
+        "open" => {
+            if args.len() < 3 {
+                eprintln!("用法: readflow open <文件路径>");
+                return;
+            }
+            open_document(&args[2]);
+        }
+        "search" => {
+            if args.len() < 4 {
+                eprintln!("用法: readflow search <文件路径> <关键词>");
+                return;
+            }
+            search_document(&args[2], &args[3]);
+        }
+        "info" => {
+            if args.len() < 3 {
+                eprintln!("用法: readflow info <文件路径>");
+                return;
+            }
+            show_document_info(&args[2]);
+        }
+        "help" | "--help" | "-h" => {
+            print_help();
+        }
+        _ => {
+            // 尝试直接打开文件
+            open_document(&args[1]);
+        }
+    }
 }
 
-// 后续实现：Dioxus 组件
-// pub fn App(cx: Scope) -> Element {
-//     cx.render(rsx! {
-//         div { "Hello, ReadFlow!" }
-//     })
-// }
\ No newline at end of file
+fn print_help() {
+    println!("用法:");
+    println!("  readflow <文件路径>           打开文档");
+    println!("  readflow open <文件路径>      打开文档");
+    println!("  readflow info <文件路径>      显示文档信息");
+    println!("  readflow search <文件> <关键词>  搜索文档内容");
+    println!();
+    println!("支持格式: PDF, EPUB, MOBI, TXT, Markdown, 代码文件");
+}
+
+fn open_document(path: &str) {
+    println!("正在打开: {}", path);
+    println!("{}", "-".repeat(50));
+    
+    let engine = DocumentEngine::new();
+    
+    match engine.open(path) {
+        Ok(doc) => {
+            println!("✅ 文档打开成功!");
+            println!();
+            println!("📖 {}", doc.title);
+            println!("📄 格式: {:?}", doc.format);
+            println!("📑 页数: {}", doc.metadata.page_count);
+            println!("💾 大小: {} bytes", doc.metadata.file_size);
+            println!();
+            
+            // 渲染文档内容（简化版）
+            match engine.render(&doc) {
+                Ok(html) => {
+                    // 只显示前几行
+                    let preview: String = html.lines().take(20).collect();
+                    println!("预览:\n{}", preview);
+                }
+                Err(e) => {
+                    eprintln!("渲染失败: {}", e);
+                }
+            }
+        }
+        Err(e) => {
+            eprintln!("❌ 打开失败: {}", e);
+        }
+    }
+}
+
+fn search_document(path: &str, query: &str) {
+    println!("在 {} 中搜索: {}", path, query);
+    println!("{}", "-".repeat(50));
+    
+    let engine = DocumentEngine::new();
+    
+    let doc = match engine.open(path) {
+        Ok(d) => d,
+        Err(e) => {
+            eprintln!("❌ 打开失败: {}", e);
+            return;
+        }
+    };
+    
+    match engine.search(&doc, query) {
+        Ok(results) => {
+            println!("找到 {} 个结果:", results.len());
+            println!();
+            
+            for (i, result) in results.iter().take(10).enumerate() {
+                println!("[{}.] 第 {} 页", i + 1, result.page);
+                println!("    上下文: ...{}...", result.context);
+                println!();
+            }
+            
+            if results.len() > 10 {
+                println!("... 还有 {} 个结果", results.len() - 10);
+            }
+        }
+        Err(e) => {
+            eprintln!("❌ 搜索失败: {}", e);
+        }
+    }
+}
+
+fn show_document_info(path: &str) {
+    println!("文档信息: {}", path);
+    println!("{}", "-".repeat(50));
+    
+    let engine = DocumentEngine::new();
+    
+    match engine.open(path) {
+        Ok(doc) => {
+            println!("标题: {}", doc.title);
+            println!("路径: {}", doc.path);
+            println!("格式: {:?}", doc.format);
+            println!();
+            println!("元数据:");
+            println!("  页数: {}", doc.metadata.page_count);
+            println!("  文件大小: {} bytes", doc.metadata.file_size);
+            println!("  作者: {:?}", doc.metadata.author);
+            println!();
+            
+            // 获取目录
+            match engine.get_toc(&doc) {
+                Ok(toc) => {
+                    if toc.is_empty() {
+                        println!("目录: (无)");
+                    } else {
+                        println!("目录:");
+                        for entry in toc {
+                            let indent = "  ".repeat(entry.level);
+                            println!("{}{}. {}", indent, entry.page, entry.title);
+                        }
+                    }
+                }
+                Err(e) => {
+                    println!("获取目录失败: {}", e);
+                }
+            }
+        }
+        Err(e) => {
+            eprintln!("❌ 获取信息失败: {}", e);
+        }
+    }
+}
\ No newline at end of file