diff --git a/snapshot/storage/s3.py b/snapshot/storage/s3.py
index a08c435..5c454dc 100644
--- a/snapshot/storage/s3.py
+++ b/snapshot/storage/s3.py
@@ -82,7 +82,10 @@ class S3Storage(StorageAdapter):
             aws_access_key_id=access_key,
             aws_secret_access_key=secret_key,
             region_name="us-east-1",
-            config=BotoConfig(signature_version="s3v4"),
+            config=BotoConfig(
+                signature_version='s3v4',
+                s3={'addressing_style': 'path'},
+            ),
         )
         self._ClientError = ClientError
         self._connect_and_ensure_bucket()
diff --git a/src/commands.ts b/src/commands.ts
index 9e97be7..b2140b7 100644
--- a/src/commands.ts
+++ b/src/commands.ts
@@ -64,12 +64,27 @@ export function registerCommands(
           name,
           description
         );
-        if (result.skipped) {
-          // Content hash matches the most recent version — nothing to save.
-          Notification.warning(result.message ?? '内容未变更，已跳过保存');
-        } else if (result.entry) {
+        // eslint-disable-next-line no-console
+        console.log('[snapshot] commit response:', result);
+        if (result && result.skipped) {
+          // Hash matched the most recent version — nothing to save. Use
+          // autoClose:false so the warning stays visible until the user
+          // dismisses it (the default 4-5s timeout is easy to miss).
+          Notification.warning(
+            result.message ?? '内容未变更，已跳过保存',
+            { autoClose: false }
+          );
+        } else if (result && result.entry) {
           await model.refresh();
           Notification.success(`已保存快照：${name}`);
+        } else {
+          // Unexpected response shape — surface clearly so the user is not
+          // left wondering whether the save happened.
+          // eslint-disable-next-line no-console
+          console.warn('[snapshot] unexpected commit response shape:', result);
+          Notification.warning('保存响应格式异常，请查看浏览器控制台', {
+            autoClose: false
+          });
         }
       } catch (e) {
         Notification.error(`保存快照失败：${(e as Error).message}`);
diff --git a/src/widgets/SnapshotPanel.tsx b/src/widgets/SnapshotPanel.tsx
index 3b03a15..b25b172 100644
--- a/src/widgets/SnapshotPanel.tsx
+++ b/src/widgets/SnapshotPanel.tsx
@@ -46,70 +46,84 @@ const Panel: React.FC<PanelProps> = ({ model, app, tracker, serverSettings, onOp
   if (!model.path) {
     return <div className="jp-snapshot-panel-empty">未选中 notebook</div>;
   }
-  if (model.loading && model.versions.length === 0) {
-    return <div className="jp-snapshot-panel-empty">加载中…</div>;
-  }
-  if (model.versions.length === 0) {
-    return (
-      <div className="jp-snapshot-panel-empty">
-        <div>暂无快照</div>
-        <div className="jp-snapshot-panel-hint">点击工具栏「保存快照」按钮创建</div>
-      </div>
-    );
-  }
   return (
-    <ul className="jp-snapshot-panel-list">
-      {model.versions.map(v => (
-        <li key={v.id} className="jp-snapshot-panel-item">
-          <div className="jp-snapshot-panel-item-header">
-            <span className="jp-snapshot-panel-name" title={v.name}>
-              {v.name}
-            </span>
-            <span className="jp-snapshot-panel-size">{formatSize(v.size)}</span>
+    <div className="jp-snapshot-panel-container">
+      <div className="jp-snapshot-panel-toolbar">
+        <button
+          className="jp-snapshot-panel-refresh-button"
+          onClick={() => {
+            void model.refresh();
+          }}
+          disabled={model.loading}
+          title="重新拉取版本列表"
+        >
+          {model.loading ? '刷新中…' : '刷新'}
+        </button>
+      </div>
+      {model.loading && model.versions.length === 0 ? (
+        <div className="jp-snapshot-panel-empty">加载中…</div>
+      ) : model.versions.length === 0 ? (
+        <div className="jp-snapshot-panel-empty">
+          <div>暂无快照</div>
+          <div className="jp-snapshot-panel-hint">
+            点击工具栏「保存快照」按钮创建
           </div>
-          {v.description ? (
-            <div className="jp-snapshot-panel-desc">{v.description}</div>
-          ) : null}
-          <div className="jp-snapshot-panel-time">{formatTimestamp(v.timestamp)}</div>
-          <div className="jp-snapshot-panel-actions">
-            <button
-              className="jp-snapshot-panel-button"
-              onClick={async () => {
-                const panel = tracker.currentWidget;
-                if (!panel) {
-                  return;
-                }
-                const notebookModel = panel.content.model;
-                if (!notebookModel) {
-                  return;
-                }
-                try {
-                  const oldNb = (await getSnapshotContent(
-                    serverSettings,
-                    model.path,
-                    v.id
-                  )) as INotebook;
-                  const newNb = notebookModel.toJSON() as unknown as INotebook;
-                  onOpenDiff(newNb, oldNb, v.name);
-                } catch (e) {
-                  console.error('Diff failed', e);
-                }
-              }}
-            >
-              对比
-            </button>
-            <button
-              className="jp-snapshot-panel-button"
-              onClick={() => {
-                void app.commands.execute(CommandIDs.restore, { id: v.id });
-              }}
-            >
-              恢复
-            </button>
-          </div>
-        </li>
-      ))}
-    </ul>
+        </div>
+      ) : (
+        <ul className="jp-snapshot-panel-list">
+          {model.versions.map(v => (
+            <li key={v.id} className="jp-snapshot-panel-item">
+              <div className="jp-snapshot-panel-item-header">
+                <span className="jp-snapshot-panel-name" title={v.name}>
+                  {v.name}
+                </span>
+                <span className="jp-snapshot-panel-size">{formatSize(v.size)}</span>
+              </div>
+              {v.description ? (
+                <div className="jp-snapshot-panel-desc">{v.description}</div>
+              ) : null}
+              <div className="jp-snapshot-panel-time">{formatTimestamp(v.timestamp)}</div>
+              <div className="jp-snapshot-panel-actions">
+                <button
+                  className="jp-snapshot-panel-button"
+                  onClick={async () => {
+                    const panel = tracker.currentWidget;
+                    if (!panel) {
+                      return;
+                    }
+                    const notebookModel = panel.content.model;
+                    if (!notebookModel) {
+                      return;
+                    }
+                    try {
+                      const oldNb = (await getSnapshotContent(
+                        serverSettings,
+                        model.path,
+                        v.id
+                      )) as INotebook;
+                      const newNb = notebookModel.toJSON() as unknown as INotebook;
+                      onOpenDiff(newNb, oldNb, v.name);
+                    } catch (e) {
+                      console.error('Diff failed', e);
+                    }
+                  }}
+                >
+                  对比
+                </button>
+                <button
+                  className="jp-snapshot-panel-button"
+                  onClick={() => {
+                    void app.commands.execute(CommandIDs.restore, { id: v.id });
+                  }}
+                >
+                  恢复
+                </button>
+              </div>
+            </li>
+          ))}
+        </ul>
+      )}
+    </div>
   );
 };
 
diff --git a/style/base.css b/style/base.css
index ec6f0d1..859dc83 100644
--- a/style/base.css
+++ b/style/base.css
@@ -13,6 +13,37 @@
   box-sizing: border-box;
 }
 
+.jp-snapshot-panel-container {
+  display: flex;
+  flex-direction: column;
+  height: 100%;
+}
+
+.jp-snapshot-panel-toolbar {
+  display: flex;
+  justify-content: flex-end;
+  margin-bottom: 6px;
+}
+
+.jp-snapshot-panel-refresh-button {
+  font-size: 0.8em;
+  padding: 2px 8px;
+  border: 1px solid var(--jp-border-color2, #ccc);
+  border-radius: 3px;
+  background: var(--jp-layout-color2, #f5f5f5);
+  color: var(--jp-ui-font-color1, #333);
+  cursor: pointer;
+}
+
+.jp-snapshot-panel-refresh-button:hover:not(:disabled) {
+  background: var(--jp-layout-color3, #e8e8e8);
+}
+
+.jp-snapshot-panel-refresh-button:disabled {
+  opacity: 0.6;
+  cursor: not-allowed;
+}
+
 .jp-snapshot-panel-empty {
   color: var(--jp-ui-font-color2, #555);
   padding: 12px;