diff --git a/static/js/note-editor.js b/static/js/note-editor.js
index 7b5bbd4..6105491 100644
--- a/static/js/note-editor.js
+++ b/static/js/note-editor.js
@@ -152,7 +152,7 @@ const NoteEditor = {
      */
     async exportPDF() {
         if (!this.analysisId) {
-            alert('请先完成审查再导出 PDF');
+            showToast('请先完成审查再导出 PDF', 'warning');
             return;
         }
 
@@ -189,7 +189,7 @@ const NoteEditor = {
             document.body.removeChild(a);
             URL.revokeObjectURL(url);
         } catch (err) {
-            alert('PDF 导出失败: ' + err.message);
+            showToast('PDF 导出失败: ' + err.message, 'error');
         } finally {
             if (btn) {
                 btn.disabled = false;
diff --git a/templates/layouts/base.html b/templates/layouts/base.html
index 04425fc..5f0c623 100644
--- a/templates/layouts/base.html
+++ b/templates/layouts/base.html
@@ -6,6 +6,48 @@
     <script src="https://cdn.tailwindcss.com"></script>
     <link rel="stylesheet" href="/static/css/style.css">
     <script src="/static/js/htmx.min.js"></script>
+    <style>
+        .toast-enter { transform: translateX(100%); opacity: 0; }
+        .toast-active { transform: translateX(0); opacity: 1; transition: transform 0.3s ease, opacity 0.3s ease; }
+        .toast-exit { transform: translateX(100%); opacity: 0; transition: transform 0.3s ease, opacity 0.3s ease; }
+    </style>
+    <script>
+        // Global toast notification system
+        (function() {
+            function ensureContainer() {
+                var c = document.getElementById('toast-container');
+                if (!c) {
+                    c = document.createElement('div');
+                    c.id = 'toast-container';
+                    c.className = 'fixed top-4 right-4 z-50 flex flex-col items-end space-y-2';
+                    document.body.appendChild(c);
+                }
+                return c;
+            }
+            window.showToast = function(message, type) {
+                type = type || 'info';
+                var colors = {
+                    success: 'bg-green-50 border-green-200 text-green-800',
+                    error:   'bg-red-50 border-red-200 text-red-800',
+                    info:    'bg-blue-50 border-blue-200 text-blue-800',
+                    warning: 'bg-yellow-50 border-yellow-200 text-yellow-800'
+                };
+                var icons = { success: '✓', error: '✗', info: 'ℹ', warning: '⚠' };
+                var container = ensureContainer();
+                var el = document.createElement('div');
+                el.className = 'px-4 py-3 rounded-md border text-sm shadow-lg max-w-sm toast-enter ' + (colors[type] || colors.info);
+                el.innerHTML = '<span class="mr-2 font-bold">' + (icons[type] || icons.info) + '</span>' +
+                    '<span>' + message + '</span>' +
+                    '<button onclick="this.parentElement.remove()" class="ml-3 text-current opacity-50 hover:opacity-100">&times;</button>';
+                container.appendChild(el);
+                requestAnimationFrame(function() { el.className = el.className.replace('toast-enter', 'toast-active'); });
+                setTimeout(function() {
+                    el.className = el.className.replace('toast-active', 'toast-exit');
+                    setTimeout(function() { el.remove(); }, 300);
+                }, 4000);
+            };
+        })();
+    </script>
 </head>
 {{end}}
 
diff --git a/templates/pages/generate.html b/templates/pages/generate.html
index 013bc2a..79213a1 100644
--- a/templates/pages/generate.html
+++ b/templates/pages/generate.html
@@ -191,7 +191,7 @@
             const headRef = document.getElementById('head-ref').value;
 
             if (!baseRef || !headRef) {
-                alert('请选择 Base 和 Head 分支');
+                showToast('请选择 Base 和 Head 分支', 'warning');
                 return;
             }
 
@@ -258,7 +258,7 @@
                     btn.textContent = '生成 PR 描述';
                 },
                 error(data) {
-                    alert('生成失败: ' + (data.message || '未知错误'));
+                    showToast('生成失败: ' + (data.message || '未知错误'), 'error');
                     streaming.classList.add('hidden');
                     output.classList.add('hidden');
                     btn.disabled = false;
@@ -275,7 +275,7 @@
         function copyMarkdown() {
             const markdown = markdownContent || document.getElementById('pr-markdown').textContent;
             navigator.clipboard.writeText(markdown).then(() => {
-                alert('已复制到剪贴板');
+                showToast('已复制到剪贴板', 'success');
             }).catch(() => {
                 const textarea = document.createElement('textarea');
                 textarea.value = markdown;
@@ -283,7 +283,7 @@
                 textarea.select();
                 document.execCommand('copy');
                 document.body.removeChild(textarea);
-                alert('已复制到剪贴板');
+                showToast('已复制到剪贴板', 'success');
             });
         }
 
diff --git a/templates/pages/repo.html b/templates/pages/repo.html
index a11139b..483e58a 100644
--- a/templates/pages/repo.html
+++ b/templates/pages/repo.html
@@ -405,7 +405,7 @@
             const base = document.getElementById('select-base').value;
             const head = document.getElementById('select-head').value;
             if (!base || !head) {
-                alert('请选择 Base 和 Head 分支');
+                showToast('请选择 Base 和 Head 分支', 'warning');
                 return;
             }
             DiffViewer.loadDiff(repoId, base, head);
@@ -436,7 +436,7 @@
             const base = document.getElementById('select-base').value;
             const head = document.getElementById('select-head').value;
             if (!base || !head) {
-                alert('请先选择 Base 和 Head 并查看 Diff');
+                showToast('请先选择 Base 和 Head 并查看 Diff', 'warning');
                 return;
             }
 
@@ -499,7 +499,7 @@
                     viewLink.href = `/repo/${repoId}/review?base=${encodeURIComponent(base)}&head=${encodeURIComponent(head)}`;
                 },
                 error(data) {
-                    alert('审查失败: ' + (data.message || '未知错误'));
+                    showToast('审查失败: ' + (data.message || '未知错误'), 'error');
                     progress.classList.add('hidden');
                     btn.disabled = false;
                     btn.textContent = '🤖 AI 评审';
diff --git a/templates/pages/review.html b/templates/pages/review.html
index c769b5e..3a2ace0 100644
--- a/templates/pages/review.html
+++ b/templates/pages/review.html
@@ -229,7 +229,7 @@
             const topN = document.getElementById('top-n').value;
 
             if (!baseRef || !headRef) {
-                alert('请选择 Base 和 Head 分支');
+                showToast('请选择 Base 和 Head 分支', 'warning');
                 return;
             }
 
@@ -340,7 +340,7 @@
                     NoteEditor.loadNotes();
                 },
                 error(data) {
-                    alert('审查失败: ' + (data.message || '未知错误'));
+                    showToast('审查失败: ' + (data.message || '未知错误'), 'error');
                     progress.classList.add('hidden');
                     btn.disabled = false;
                     btn.textContent = '开始审查';
@@ -471,7 +471,7 @@
 
                 const result = data.result;
                 if (!result || !result.file_reviews) {
-                    alert('该历史记录没有完整的评审数据');
+                    showToast('该历史记录没有完整的评审数据', 'warning');
                     return;
                 }
 
@@ -533,7 +533,7 @@
 
             } catch (e) {
                 console.error('Load history error:', e);
-                alert('加载历史评审失败: ' + e.message);
+                showToast('加载历史评审失败: ' + e.message, 'error');
             }
         }