diff --git a/src-tauri/data.sql b/src-tauri/data.sql
index 34d90ab..c8b719d 100644
Binary files a/src-tauri/data.sql and b/src-tauri/data.sql differ
diff --git a/src/components/AutoScoreManager.tsx b/src/components/AutoScoreManager.tsx
index b5c8f25..2fd4f22 100644
--- a/src/components/AutoScoreManager.tsx
+++ b/src/components/AutoScoreManager.tsx
@@ -27,6 +27,7 @@ import {
   createEmptyTriggerTree,
   createTriggerQueryConfig,
   hasUnsupportedTriggerLogic,
+  normalizeActionDrafts,
   queryTreeToTriggers,
   triggersToQueryTree,
   type ActionDraft,
@@ -183,7 +184,15 @@ function AutoScoreManager({ canEdit }: AutoScoreManagerProps): React.JSX.Element
       return
     }
 
-    const actionPayload = actionDraftsToPayload(actionDrafts)
+    const normalizedActionDrafts = normalizeActionDrafts(actionDrafts)
+    const actionPayload = actionDraftsToPayload(normalizedActionDrafts)
+    if (actionDrafts.length === 0) {
+      setActionDrafts(normalizedActionDrafts)
+    }
+    if (actionPayload.error === "action_required") {
+      messageApi.warning(t("autoScore.actionRequired"))
+      return
+    }
     if (actionPayload.error === "score_required") {
       messageApi.warning(t("autoScore.scorePlaceholder"))
       return
@@ -423,7 +432,7 @@ function AutoScoreManager({ canEdit }: AutoScoreManagerProps): React.JSX.Element
         value={actionDrafts}
         tagOptions={tagOptions}
         canEdit={canEdit}
-        onChange={setActionDrafts}
+        onChange={(nextDrafts) => setActionDrafts(normalizeActionDrafts(nextDrafts))}
       />
 
       <div style={{ marginBottom: "24px", display: "flex", gap: "12px" }}>
diff --git a/src/components/AutoScoreManagerPage/ActionEditor.tsx b/src/components/AutoScoreManagerPage/ActionEditor.tsx
index ab97de4..8508edb 100644
--- a/src/components/AutoScoreManagerPage/ActionEditor.tsx
+++ b/src/components/AutoScoreManagerPage/ActionEditor.tsx
@@ -1,4 +1,4 @@
-import React, { useMemo } from "react"
+import React, { useEffect, useMemo } from "react"
 import { Button, Card, InputNumber, Select, Space } from "antd"
 import { DeleteOutlined, PlusOutlined } from "@ant-design/icons"
 import { useTranslation } from "react-i18next"
@@ -19,6 +19,14 @@ export const ActionEditor: React.FC<ActionEditorProps> = ({
   onChange,
 }) => {
   const { t } = useTranslation()
+  const fallbackDraft = useMemo(() => createDefaultActionDraft(), [])
+  const safeValue = value.length > 0 ? value : [fallbackDraft]
+
+  useEffect(() => {
+    if (value.length === 0) {
+      onChange([fallbackDraft])
+    }
+  }, [fallbackDraft, onChange, value.length])
 
   const actionOptions = useMemo(
     () => [
@@ -31,7 +39,7 @@ export const ActionEditor: React.FC<ActionEditorProps> = ({
   const mergedTagOptions = useMemo(() => {
     const optionMap = new Map(tagOptions.map((option) => [option.value, option]))
 
-    for (const action of value) {
+    for (const action of safeValue) {
       if (action.event !== "add_tag") continue
       const tagValues = Array.isArray(action.value)
         ? action.value
@@ -47,19 +55,19 @@ export const ActionEditor: React.FC<ActionEditorProps> = ({
     }
 
     return Array.from(optionMap.values())
-  }, [tagOptions, value])
+  }, [safeValue, tagOptions])
 
   const updateAction = (id: string, patch: Partial<Omit<ActionDraft, "id">>) => {
-    onChange(value.map((item) => (item.id === id ? { ...item, ...patch } : item)))
+    onChange(safeValue.map((item) => (item.id === id ? { ...item, ...patch } : item)))
   }
 
   const handleAddAction = () => {
-    onChange([...value, createDefaultActionDraft()])
+    onChange([...safeValue, createDefaultActionDraft()])
   }
 
   const handleRemoveAction = (id: string) => {
-    if (value.length <= 1) return
-    onChange(value.filter((item) => item.id !== id))
+    if (safeValue.length <= 1) return
+    onChange(safeValue.filter((item) => item.id !== id))
   }
 
   return (
@@ -68,7 +76,7 @@ export const ActionEditor: React.FC<ActionEditorProps> = ({
       title={t("autoScore.triggeredActions")}
     >
       <Space direction="vertical" style={{ width: "100%" }} size={12}>
-        {value.map((action) => (
+        {safeValue.map((action) => (
           <div key={action.id} style={{ display: "flex", gap: "8px", alignItems: "center" }}>
             <Select
               style={{ minWidth: 180 }}
@@ -108,7 +116,7 @@ export const ActionEditor: React.FC<ActionEditorProps> = ({
             <Button
               danger
               icon={<DeleteOutlined />}
-              disabled={!canEdit || value.length <= 1}
+              disabled={!canEdit || safeValue.length <= 1}
               onClick={() => handleRemoveAction(action.id)}
             />
           </div>
diff --git a/src/components/AutoScoreManagerPage/AutoScoreUtils.ts b/src/components/AutoScoreManagerPage/AutoScoreUtils.ts
index 30813cc..8bc2de7 100644
--- a/src/components/AutoScoreManagerPage/AutoScoreUtils.ts
+++ b/src/components/AutoScoreManagerPage/AutoScoreUtils.ts
@@ -43,7 +43,7 @@ export interface ActionDraft {
   value: string | string[]
 }
 
-export type ActionDraftError = "score_required" | "tag_required" | null
+export type ActionDraftError = "action_required" | "score_required" | "tag_required" | null
 
 const TRIGGER_FIELD_INTERVAL = "interval_minutes"
 const TRIGGER_FIELD_TAG = "student_tag"
@@ -312,6 +312,32 @@ export const createDefaultActionDraft = (): ActionDraft => ({
   value: "1",
 })
 
+const isActionEvent = (value: unknown): value is ActionEvent =>
+  value === "add_score" || value === "add_tag"
+
+export const normalizeActionDrafts = (drafts: ActionDraft[] | null | undefined): ActionDraft[] => {
+  if (!Array.isArray(drafts) || drafts.length === 0) {
+    return [createDefaultActionDraft()]
+  }
+
+  const normalized = drafts
+    .map((draft) => {
+      if (!draft || !isActionEvent(draft.event)) return null
+
+      return {
+        id: typeof draft.id === "string" && draft.id ? draft.id : QbUtils.uuid(),
+        event: draft.event,
+        value:
+          draft.event === "add_tag"
+            ? parseTagValues(draft.value)
+            : toStringValue(Array.isArray(draft.value) ? draft.value[0] : draft.value),
+      } satisfies ActionDraft
+    })
+    .filter((item): item is ActionDraft => Boolean(item))
+
+  return normalized.length > 0 ? normalized : [createDefaultActionDraft()]
+}
+
 export const actionsToDrafts = (actions: AutoScoreAction[]): ActionDraft[] => {
   const mapped = actions
     .map((action) => {
@@ -325,14 +351,19 @@ export const actionsToDrafts = (actions: AutoScoreAction[]): ActionDraft[] => {
     })
     .filter((item): item is ActionDraft => Boolean(item))
 
-  return mapped.length > 0 ? mapped : [createDefaultActionDraft()]
+  return normalizeActionDrafts(mapped)
 }
 
 export const actionDraftsToPayload = (
   drafts: ActionDraft[]
 ): { actions: AutoScoreAction[]; error: ActionDraftError } => {
+  const normalizedDrafts = normalizeActionDrafts(drafts)
+  if (normalizedDrafts.length === 0) {
+    return { actions: [], error: "action_required" }
+  }
+
   const actions: AutoScoreAction[] = []
-  for (const draft of drafts) {
+  for (const draft of normalizedDrafts) {
     if (draft.event === "add_score") {
       const score = Array.isArray(draft.value) ? null : toFiniteNumber(draft.value)
       if (!score || score === 0) {
diff --git a/src/components/Settings.tsx b/src/components/Settings.tsx
index 3191b36..67b91a7 100644
--- a/src/components/Settings.tsx
+++ b/src/components/Settings.tsx
@@ -30,6 +30,18 @@ type appSettings = {
   window_zoom?: string
   search_keyboard_layout?: "t9" | "qwerty26"
   disable_search_keyboard?: boolean
+  font_family?: string
+}
+
+interface FontOption {
+  value: string
+  label: string
+  fontFamily: string
+}
+
+const applyFontFamily = (fontFamily: string) => {
+  document.documentElement.style.setProperty("--ss-font-family", fontFamily)
+  document.body.style.fontFamily = fontFamily
 }
 const withTimeout = async (
   promise: Promise<any>,
@@ -64,6 +76,8 @@ export const Settings: React.FC<{
     search_keyboard_layout: "qwerty26",
     disable_search_keyboard: false,
   })
+  const [fontOptions, setFontOptions] = useState<FontOption[]>([])
+  const [isLoadingFonts, setIsLoadingFonts] = useState(true)
 
   const [securityStatus, setSecurityStatus] = useState<{
     permission: permissionLevel
@@ -173,6 +187,36 @@ export const Settings: React.FC<{
     }
   }
 
+  const loadSystemFonts = async () => {
+    if (!(window as any).api?.getSystemFonts) return
+
+    setIsLoadingFonts(true)
+    try {
+      const res = await (window as any).api.getSystemFonts()
+      if (res.success && Array.isArray(res.data)) {
+        const fontList = res.data
+          .map((name: string) => ({
+            value: `system-${name}`,
+            label: name,
+            fontFamily: `"${name}"`,
+          })) as FontOption[]
+
+        setFontOptions(fontList)
+
+        if (settings.font_family) {
+          const currentFontOpt = fontList.find((f) => f.value === settings.font_family)
+          if (currentFontOpt) {
+            applyFontFamily(currentFontOpt.fontFamily)
+          }
+        }
+      }
+    } catch (error) {
+      console.error("Failed to load system fonts:", error)
+    } finally {
+      setIsLoadingFonts(false)
+    }
+  }
+
   const loadAll = async () => {
     if (!(window as any).api) return
     const res = await (window as any).api.getAllSettings()
@@ -180,10 +224,17 @@ export const Settings: React.FC<{
       setSettings(res.data)
       setPgConnectionString(res.data.pg_connection_string || "")
       setPgConnectionStatus(res.data.pg_connection_status || { connected: true, type: "sqlite" })
+      if (res.data.font_family) {
+        const fontOpt = fontOptions.find((f) => f.value === res.data.font_family)
+        if (fontOpt) {
+          applyFontFamily(fontOpt.fontFamily)
+        }
+      }
     }
     const authRes = await (window as any).api.authGetStatus()
     if (authRes.success && authRes.data) setSecurityStatus(authRes.data)
     await loadMcpStatus()
+    await loadSystemFonts()
   }
 
   const loadAboutContent = async () => {
@@ -220,6 +271,13 @@ export const Settings: React.FC<{
             return { ...prev, disable_search_keyboard: Boolean(change.value) }
           if (change?.key === "auto_score_enabled")
             return { ...prev, auto_score_enabled: change.value }
+          if (change?.key === "font_family") {
+            const fontOpt = fontOptions.find((f) => f.value === change.value)
+            if (fontOpt) {
+              applyFontFamily(fontOpt.fontFamily)
+            }
+            return { ...prev, font_family: change.value }
+          }
           return prev
         })
       })
@@ -664,6 +722,43 @@ export const Settings: React.FC<{
           <Divider />
 
           <Form layout="horizontal" labelCol={{ span: 4 }} wrapperCol={{ span: 20 }}>
+            <Form.Item label={t("settings.fontFamily")}>
+              <Select
+                value={settings.font_family || "system"}
+                onChange={async (v) => {
+                  const fontOpt = fontOptions.find((f) => f.value === v)
+                  if (!fontOpt) return
+                  applyFontFamily(fontOpt.fontFamily)
+                  setSettings((prev) => ({ ...prev, font_family: v }))
+                  if ((window as any).api) {
+                    const res = await (window as any).api.setSetting("font_family", v)
+                    if (res.success) {
+                      messageApi.success(t("settings.general.saved"))
+                    } else {
+                      messageApi.error(res.message || t("settings.general.saveFailed"))
+                    }
+                  } else {
+                    messageApi.success(t("settings.general.saved"))
+                  }
+                }}
+                style={{ width: "320px" }}
+                loading={isLoadingFonts}
+                options={fontOptions.map((opt) => ({
+                  value: opt.value,
+                  label: opt.label,
+                }))}
+                showSearch
+                filterOption={(input, option) =>
+                  (option?.label ?? "").toLowerCase().includes(input.toLowerCase())
+                }
+              />
+              <div
+                style={{ marginTop: "4px", fontSize: "12px", color: "var(--ss-text-secondary)" }}
+              >
+                {t("settings.fontFamilyHint")}
+              </div>
+            </Form.Item>
+
             {!isMobile && (
               <>
                 <Form.Item label={t("settings.searchKeyboard.title")}>
diff --git a/src/i18n/locales/en-US.json b/src/i18n/locales/en-US.json
index 6947474..75a8700 100644
--- a/src/i18n/locales/en-US.json
+++ b/src/i18n/locales/en-US.json
@@ -135,6 +135,8 @@
     },
     "language": "Language",
     "languageHint": "Select interface display language",
+    "fontFamily": "Global Font",
+    "fontFamilyHint": "Select the application interface font (page refresh required for full effect)",
     "theme": "Theme",
     "password": "Set Password",
     "themeMode": "Mode",
diff --git a/src/i18n/locales/zh-CN.json b/src/i18n/locales/zh-CN.json
index 5a7266b..d35a659 100644
--- a/src/i18n/locales/zh-CN.json
+++ b/src/i18n/locales/zh-CN.json
@@ -135,6 +135,8 @@
     },
     "language": "语言",
     "languageHint": "选择界面显示语言",
+    "fontFamily": "全局字体",
+    "fontFamilyHint": "选择应用界面的字体（需要刷新页面以完全生效）",
     "theme": "主题",
     "password": "设置密码",
     "themeMode": "模式",