diff --git a/cli/src/main.rs b/cli/src/main.rs
index 638c8f1..c20a17b 100644
--- a/cli/src/main.rs
+++ b/cli/src/main.rs
@@ -74,7 +74,7 @@ fn main() -> anyhow::Result<()> {
 
             match ext.as_str() {
                 "png" => {
-                    let bytes = qr.to_png_bytes(args.size);
+                    let bytes = qr.to_png_bytes(args.size)?;
                     std::fs::write(&path, bytes)?;
                     println!(
                         "已生成: {} (版本 {}, {}×{} 模块, {} 级纠错)",
diff --git a/core/src/ecc/galois.rs b/core/src/ecc/galois.rs
index 33fa720..c28d807 100644
--- a/core/src/ecc/galois.rs
+++ b/core/src/ecc/galois.rs
@@ -1,46 +1,40 @@
 /// GF(2⁸) Galois 域运算
 /// 本原多项式: x⁸ + x⁴ + x³ + x² + 1 = 0x11D
 /// 生成元 α = 0x02
-use std::sync::OnceLock;
+use std::sync::LazyLock;
 
-fn exp_table() -> &'static [u8; 512] {
-    static TABLE: OnceLock<[u8; 512]> = OnceLock::new();
-    TABLE.get_or_init(|| {
-        let mut table = [0u8; 512];
-        let mut x = 1u8;
-        for i in 0..255 {
-            table[i] = x;
-            table[i + 255] = x; // 双倍长度避免 % 255
-            let next = (x as u16) << 1;
-            x = if next >= 0x100 {
-                (next ^ 0x1D) as u8
-            } else {
-                next as u8
-            };
-        }
-        table[510] = table[255];
-        table[511] = table[256];
-        table
-    })
-}
+static EXP_TABLE: LazyLock<[u8; 512]> = LazyLock::new(|| {
+    let mut table = [0u8; 512];
+    let mut x = 1u8;
+    for i in 0..255 {
+        table[i] = x;
+        table[i + 255] = x; // 双倍长度避免 % 255
+        let next = (x as u16) << 1;
+        x = if next >= 0x100 {
+            (next ^ 0x1D) as u8
+        } else {
+            next as u8
+        };
+    }
+    table[510] = table[255];
+    table[511] = table[256];
+    table
+});
 
-fn log_table() -> &'static [u8; 256] {
-    static TABLE: OnceLock<[u8; 256]> = OnceLock::new();
-    TABLE.get_or_init(|| {
-        let mut table = [0u8; 256];
-        let mut x = 1u8;
-        for i in 0..255 {
-            table[x as usize] = i;
-            let next = (x as u16) << 1;
-            x = if next >= 0x100 {
-                (next ^ 0x1D) as u8
-            } else {
-                next as u8
-            };
-        }
-        table
-    })
-}
+static LOG_TABLE: LazyLock<[u8; 256]> = LazyLock::new(|| {
+    let mut table = [0u8; 256];
+    let mut x = 1u8;
+    for i in 0..255 {
+        table[x as usize] = i;
+        let next = (x as u16) << 1;
+        x = if next >= 0x100 {
+            (next ^ 0x1D) as u8
+        } else {
+            next as u8
+        };
+    }
+    table
+});
 
 /// GF(2⁸) 加法 = 异或
 #[inline]
@@ -60,9 +54,9 @@ pub fn mul(a: u8, b: u8) -> u8 {
     if a == 0 || b == 0 {
         return 0;
     }
-    let log_a = log_table()[a as usize] as usize;
-    let log_b = log_table()[b as usize] as usize;
-    exp_table()[log_a + log_b]
+    let log_a = LOG_TABLE[a as usize] as usize;
+    let log_b = LOG_TABLE[b as usize] as usize;
+    EXP_TABLE[log_a + log_b]
 }
 
 /// GF(2⁸) 除法：a / b，b == 0 时返回 None
@@ -74,10 +68,10 @@ pub fn div(a: u8, b: u8) -> Option<u8> {
     if b == 0 {
         return None;
     }
-    let log_a = log_table()[a as usize] as usize;
-    let log_b = log_table()[b as usize] as usize;
+    let log_a = LOG_TABLE[a as usize] as usize;
+    let log_b = LOG_TABLE[b as usize] as usize;
     let diff = (log_a + 255 - log_b) % 255;
-    Some(exp_table()[diff])
+    Some(EXP_TABLE[diff])
 }
 
 /// GF(2⁸) 幂运算：base^exp
@@ -89,8 +83,8 @@ pub fn pow(base: u8, exp: usize) -> u8 {
     if base == 0 {
         return 0;
     }
-    let log_b = log_table()[base as usize] as usize;
-    exp_table()[(log_b * exp) % 255]
+    let log_b = LOG_TABLE[base as usize] as usize;
+    EXP_TABLE[(log_b * exp) % 255]
 }
 
 #[cfg(test)]
diff --git a/core/src/encoder/mode.rs b/core/src/encoder/mode.rs
index 92ed5dd..6e7c82a 100644
--- a/core/src/encoder/mode.rs
+++ b/core/src/encoder/mode.rs
@@ -163,8 +163,8 @@ fn unicode_to_shift_jis(c: char) -> Option<u16> {
         let sjis = ((hi << 8) | lo) as u16;
         // 映射到 13-bit 码字（内层 if/else 已区分两个 Shift-JIS 区间）
         let val = {
-            let h = (sjis >> 8);
-            let l = (sjis & 0xFF);
+            let h = sjis >> 8;
+            let l = sjis & 0xFF;
             if (0x81..=0x9F).contains(&h) {
                 (h - 0x81) * 0xBC + (l - 0x40)
             } else {
@@ -277,6 +277,37 @@ mod tests {
         assert!(!is_kanji('A'));
     }
 
+    #[test]
+    fn test_kanji_encode_basic() {
+        // 常用汉字 "中文" 应能编码且长度正确
+        let bits = encode_kanji("中文");
+        // 2 个汉字，每个 13 bit = 26 bit
+        assert_eq!(bits.len(), 26);
+    }
+
+    #[test]
+    fn test_unicode_to_shift_jis_known() {
+        // 基本汉字应返回 Some
+        assert!(unicode_to_shift_jis('中').is_some());
+        assert!(unicode_to_shift_jis('文').is_some());
+        assert!(unicode_to_shift_jis('你').is_some());
+    }
+
+    #[test]
+    fn test_unicode_to_shift_jis_ascii_returns_none() {
+        // ASCII 字符不是汉字
+        assert!(unicode_to_shift_jis('A').is_none());
+        assert!(unicode_to_shift_jis('1').is_none());
+    }
+
+    #[test]
+    fn test_kanji_mode_fallback() {
+        // 非 CJK 字符会被降级为 UTF-8 字节编码
+        let bits = encode_kanji("A");
+        // 1 个 ASCII 字符 = 8 bit
+        assert_eq!(bits.len(), 8);
+    }
+
     fn bits_to_u16(bits: &[bool]) -> u16 {
         bits.iter().fold(0, |acc, &b| (acc << 1) | (b as u16))
     }
diff --git a/core/src/matrix/mask.rs b/core/src/matrix/mask.rs
index eba6b70..9fce37c 100644
--- a/core/src/matrix/mask.rs
+++ b/core/src/matrix/mask.rs
@@ -185,19 +185,19 @@ fn score_rule4(matrix: &Matrix) -> u32 {
 pub fn best_mask(matrix: &Matrix) -> (u8, Matrix) {
     let mut best_idx = 0u8;
     let mut best_score = u32::MAX;
-    let mut best_matrix = matrix.clone();
+    let mut best_matrix: Option<Matrix> = None;
 
     for i in 0..8u8 {
         let masked = apply_mask(matrix, i);
         let s = score(&masked);
-        if s < best_score {
+        if best_matrix.is_none() || s < best_score {
             best_score = s;
             best_idx = i;
-            best_matrix = masked;
+            best_matrix = Some(masked);
         }
     }
 
-    (best_idx, best_matrix)
+    (best_idx, best_matrix.unwrap())
 }
 
 #[cfg(test)]
diff --git a/core/src/matrix/patterns.rs b/core/src/matrix/patterns.rs
index c50f4ef..0d77a06 100644
--- a/core/src/matrix/patterns.rs
+++ b/core/src/matrix/patterns.rs
@@ -24,6 +24,15 @@ pub fn place_finder_patterns(matrix: &mut Matrix) {
                 matrix.reserve(x, y);
             }
         }
+        // 定位图案分隔符（1 模块宽的白色边框，在 finder 周围）
+        for i in 0..8u8 {
+            if fx + 7 < matrix.size {
+                matrix.reserve(fx + 7, fy + i); // 右侧分隔列
+            }
+            if fy + 7 < matrix.size {
+                matrix.reserve(fx + i, fy + 7); // 底部隔行
+            }
+        }
     }
 }
 
@@ -59,11 +68,7 @@ fn place_single_alignment(matrix: &mut Matrix, cx: u8, cy: u8) {
     let y0 = cy - 2;
     for dy in 0..5u8 {
         for dx in 0..5u8 {
-            let is_dark = match (dx, dy) {
-                (0, _) | (4, _) | (_, 0) | (_, 4) => true,
-                (2, 2) => true,
-                _ => false,
-            };
+            let is_dark = matches!((dx, dy), (0, _) | (4, _) | (_, 0) | (_, 4) | (2, 2));
             let x = x0 + dx;
             let y = y0 + dy;
             matrix.set(x, y, is_dark);
diff --git a/core/src/qr.rs b/core/src/qr.rs
index bc9b257..dbd1867 100644
--- a/core/src/qr.rs
+++ b/core/src/qr.rs
@@ -143,7 +143,7 @@ impl QrCode {
         crate::render::ascii::render_ascii(self, invert)
     }
 
-    pub fn to_png_bytes(&self, module_size: u8) -> Vec<u8> {
+    pub fn to_png_bytes(&self, module_size: u8) -> Result<Vec<u8>, image::ImageError> {
         crate::render::png::render_png(self, module_size)
     }
 }
diff --git a/core/src/render/png.rs b/core/src/render/png.rs
index 3da61b3..c538075 100644
--- a/core/src/render/png.rs
+++ b/core/src/render/png.rs
@@ -1,7 +1,7 @@
 use crate::qr::QrCode;
 use image::{ImageBuffer, Luma};
 
-pub fn render_png(qr: &QrCode, module_size: u8) -> Vec<u8> {
+pub fn render_png(qr: &QrCode, module_size: u8) -> Result<Vec<u8>, image::ImageError> {
     let matrix_size = qr.size() as u32;
     let margin = qr.margin as u32;
     let total_size = matrix_size + 2 * margin;
@@ -34,7 +34,6 @@ pub fn render_png(qr: &QrCode, module_size: u8) -> Vec<u8> {
     }
 
     let mut buf = Vec::new();
-    img.write_to(&mut std::io::Cursor::new(&mut buf), image::ImageFormat::Png)
-        .expect("PNG 编码失败");
-    buf
+    img.write_to(&mut std::io::Cursor::new(&mut buf), image::ImageFormat::Png)?;
+    Ok(buf)
 }
diff --git a/core/tests/integration_test.rs b/core/tests/integration_test.rs
index be946f1..df8e9b1 100644
--- a/core/tests/integration_test.rs
+++ b/core/tests/integration_test.rs
@@ -83,7 +83,7 @@ fn test_ascii_output() {
 #[test]
 fn test_png_output() {
     let qr = QrCode::encode("TEST", QrConfig::default()).unwrap();
-    let png = qr.to_png_bytes(4);
+    let png = qr.to_png_bytes(4).unwrap();
     assert!(!png.is_empty());
     // PNG 文件应以 8 字节魔术签名开头
     assert_eq!(&png[..8], &[137, 80, 78, 71, 13, 10, 26, 10]);
diff --git a/gui/src-frontend/src/App.tsx b/gui/src-frontend/src/App.tsx
index f8c293b..fca0c31 100644
--- a/gui/src-frontend/src/App.tsx
+++ b/gui/src-frontend/src/App.tsx
@@ -1,4 +1,5 @@
 import { QrProvider, useQrState } from './store/qrContext';
+import ErrorBoundary from './components/ErrorBoundary';
 import ModePanel from './components/ModePanel';
 import QrPreview from './components/QrPreview';
 import ExportPanel from './components/ExportPanel';
@@ -60,8 +61,10 @@ function BottomInput() {
 
 export default function App() {
   return (
-    <QrProvider>
-      <AppLayout />
-    </QrProvider>
+    <ErrorBoundary>
+      <QrProvider>
+        <AppLayout />
+      </QrProvider>
+    </ErrorBoundary>
   );
 }
diff --git a/gui/src-frontend/src/components/ErrorBoundary.tsx b/gui/src-frontend/src/components/ErrorBoundary.tsx
new file mode 100644
index 0000000..2db1219
--- /dev/null
+++ b/gui/src-frontend/src/components/ErrorBoundary.tsx
@@ -0,0 +1,27 @@
+import React, { Component, type ReactNode } from 'react';
+
+interface Props { children: ReactNode; }
+interface State { hasError: boolean; error: Error | null; }
+
+export default class ErrorBoundary extends Component<Props, State> {
+  state: State = { hasError: false, error: null };
+
+  static getDerivedStateFromError(error: Error) { return { hasError: true, error }; }
+
+  render() {
+    if (this.state.hasError) {
+      return (
+        <div className="h-screen flex flex-col items-center justify-center gap-3 bg-gray-50 dark:bg-gray-950 text-gray-600 dark:text-gray-400">
+          <span className="text-4xl">⚠</span>
+          <h2 className="text-lg font-semibold">应用发生错误</h2>
+          <p className="text-sm max-w-md text-center">{this.state.error?.message}</p>
+          <button onClick={() => window.location.reload()}
+            className="px-4 py-2 rounded-lg bg-blue-500 text-white text-sm hover:bg-blue-600 transition-all">
+            重新加载
+          </button>
+        </div>
+      );
+    }
+    return this.props.children;
+  }
+}
diff --git a/gui/src-frontend/src/components/ExportPanel.tsx b/gui/src-frontend/src/components/ExportPanel.tsx
index a779a8f..43a6d67 100644
--- a/gui/src-frontend/src/components/ExportPanel.tsx
+++ b/gui/src-frontend/src/components/ExportPanel.tsx
@@ -45,7 +45,7 @@ export default function ExportPanel() {
       });
       await writeFile(filePath, new Uint8Array(bytes));
     } catch (e) {
-      console.error('导出 PNG 失败:', e);
+      console.warn('导出 PNG 失败:', e);
     }
     setExporting(false);
   };
@@ -60,7 +60,7 @@ export default function ExportPanel() {
       if (!filePath) return;
       await writeFile(filePath, new TextEncoder().encode(state.preview.svg));
     } catch (e) {
-      console.error('导出 SVG 失败:', e);
+      console.warn('导出 SVG 失败:', e);
     }
   };
 
diff --git a/gui/src-frontend/src/components/QrPreview.tsx b/gui/src-frontend/src/components/QrPreview.tsx
index aca6604..7e48be2 100644
--- a/gui/src-frontend/src/components/QrPreview.tsx
+++ b/gui/src-frontend/src/components/QrPreview.tsx
@@ -15,6 +15,7 @@ export default function QrPreview() {
 
   return (
     <div className="flex flex-col items-center gap-3">
+      {/* SVG 由 Rust 端 qr-core 生成，仅含 <rect> 和固定颜色，无用户文本嵌入 */}
       <div
         className="w-64 h-64 border-2 border-dashed border-gray-300 dark:border-gray-700 rounded-2xl p-4 flex items-center justify-center bg-white dark:bg-white qr-preview"
         dangerouslySetInnerHTML={{ __html: state.preview.svg }}
diff --git a/gui/src-frontend/src/hooks/useQrEncode.ts b/gui/src-frontend/src/hooks/useQrEncode.ts
index 3685973..f460152 100644
--- a/gui/src-frontend/src/hooks/useQrEncode.ts
+++ b/gui/src-frontend/src/hooks/useQrEncode.ts
@@ -1,6 +1,10 @@
-import { useCallback, useRef } from 'react';
+import { useCallback, useRef, useEffect } from 'react';
 import { invoke } from '@tauri-apps/api/core';
+import { Store } from '@tauri-apps/plugin-store';
 import { useQrState } from '../store/qrContext';
+import type { HistoryEntry } from '../types';
+
+const HISTORY_KEY = 'qr-history';
 
 interface QrResponse {
   svg: string;
@@ -15,6 +19,13 @@ export function useQrEncode() {
   const modeRef = useRef(state.mode);
   modeRef.current = state.mode;
 
+  // 组件卸载时清理定时器
+  useEffect(() => {
+    return () => {
+      if (timerRef.current) clearTimeout(timerRef.current);
+    };
+  }, []);
+
   const encode = useCallback((text: string) => {
     if (!text.trim()) {
       dispatch({ type: 'SET_PREVIEW', payload: null });
@@ -33,18 +44,26 @@ export function useQrEncode() {
         });
         dispatch({ type: 'SET_PREVIEW', payload: result });
 
-        // 保存到历史
-        dispatch({
-          type: 'ADD_HISTORY',
-          payload: {
-            id: Date.now().toString(),
-            mode: modeRef.current,
-            content: text,
-            timestamp: Date.now(),
-          },
-        });
+        // 保存到历史（内存 + 持久化）
+        const entryId = Date.now().toString();
+        const entry: HistoryEntry = {
+          id: entryId,
+          mode: modeRef.current,
+          content: text,
+          timestamp: Date.now(),
+        };
+        dispatch({ type: 'ADD_HISTORY', payload: entry });
+
+        // 持久化到 tauri-plugin-store
+        try {
+          const store = await Store.load('history.json');
+          const current = await store.get<HistoryEntry[]>(HISTORY_KEY) || [];
+          const updated = [entry, ...current].slice(0, 50);
+          await store.set(HISTORY_KEY, updated);
+          await store.save();
+        } catch { /* store 不可用时静默忽略 */ }
       } catch (e) {
-        console.error('QR 编码失败:', e);
+        // 编码失败已在 dispatch SET_PREVIEW(null) 中处理，无需额外日志
         dispatch({ type: 'SET_PREVIEW', payload: null });
       }
     }, 200);
diff --git a/gui/src-frontend/src/store/qrContext.tsx b/gui/src-frontend/src/store/qrContext.tsx
index 14ec3e0..d8a035f 100644
--- a/gui/src-frontend/src/store/qrContext.tsx
+++ b/gui/src-frontend/src/store/qrContext.tsx
@@ -1,5 +1,6 @@
-import React, { createContext, useContext, useReducer, type ReactNode } from 'react';
-import type { QrState, QrAction } from '../types';
+import React, { createContext, useContext, useReducer, useEffect, type ReactNode } from 'react';
+import { Store } from '@tauri-apps/plugin-store';
+import type { QrState, QrAction, HistoryEntry } from '../types';
 
 const initialState: QrState = {
   mode: 'text',
@@ -42,6 +43,18 @@ const QrContext = createContext<{
 
 export function QrProvider({ children }: { children: ReactNode }) {
   const [state, dispatch] = useReducer(qrReducer, initialState);
+
+  // 启动时从 store 加载持久化的历史记录
+  useEffect(() => {
+    (async () => {
+      try {
+        const store = await Store.load('history.json');
+        const history = await store.get<HistoryEntry[]>('qr-history') || [];
+        dispatch({ type: 'SET_HISTORY', payload: history });
+      } catch { /* store 不可用时忽略 */ }
+    })();
+  }, []);
+
   return <QrContext.Provider value={{ state, dispatch }}>{children}</QrContext.Provider>;
 }
 
diff --git a/gui/src/lib.rs b/gui/src/lib.rs
index 3e4daa1..4d11877 100644
--- a/gui/src/lib.rs
+++ b/gui/src/lib.rs
@@ -29,6 +29,10 @@ struct AppState {
 /// 编码 QR 码，返回 SVG + 元信息
 #[tauri::command]
 fn encode_qr(text: String, level: String, margin: u8) -> Result<QrResponse, String> {
+    if margin > 100 {
+        return Err("边距过大（最大 100）".into());
+    }
+
     let ec_level = match level.to_uppercase().as_str() {
         "L" => EcLevel::L,
         "M" => EcLevel::M,
@@ -58,6 +62,10 @@ fn encode_qr(text: String, level: String, margin: u8) -> Result<QrResponse, Stri
 /// 导出 PNG bytes
 #[tauri::command]
 fn export_png(text: String, level: String, margin: u8, module_size: u8) -> Result<Vec<u8>, String> {
+    if margin > 100 {
+        return Err("边距过大（最大 100）".into());
+    }
+
     let ec_level = match level.to_uppercase().as_str() {
         "L" => EcLevel::L,
         "M" => EcLevel::M,
@@ -74,7 +82,7 @@ fn export_png(text: String, level: String, margin: u8, module_size: u8) -> Resul
 
     let qr = QrCode::encode(&text, config).map_err(|e| format!("编码失败: {}", e))?;
 
-    Ok(qr.to_png_bytes(module_size))
+    qr.to_png_bytes(module_size).map_err(|e| format!("PNG 导出失败: {}", e))
 }
 
 /// 保存历史记录条目