1.增加了重力感应，也就是横屏响应式布局。

2.修改了沉浸式布局。
3.修改了添加日程和编辑日程页面，增加了重复、提醒等功能。
4.修改了权限问题，如果日历本是只读，则有删除线做标识。同时，对于只读的日程，点击后将不再进入编辑页面，而是展示详情。
5.系统日历的处理。给用户两个选择，第一个选择就是只显示系统日历。第二种选择，用户可以选择一个caldav账户中的某一个日历本，把系统日历中的日程，包括日历日程和应用创建的日程，都读取出来，然后加入到这个日历本下，最后同步到caldav的服务器上，这样的好处是，手机丢失了，或者换了手机品牌型号，手机上的日程仍然在自己的caldav服务器上有一个备份。当然，系统日历中的caldav日历，就不会再读取了。

entry/src/main/ets/common/AccountStore.ets

@@ -26,6 +26,8 @@ export class DavAccount {
   calendarNames: string[] = [];
   /** 服务器端定义的日历本颜色（calendar-color），与 calendarHrefs 一一对应，空串表示未定义 */
   calendarColors: string[] = [];
+  /** 各日历本写权限（'1'=可写 '0'=只读），与 calendarHrefs 一一对应；空数组表示未知（按可写处理） */
+  calendarWritable: string[] = [];
   itemCount: number = 0;
   lastSyncTime: string = '';
 }
@@ -37,6 +39,7 @@ export class CalSource {
   color: string = '#007DFF';
   source: string = 'dav'; // 'dav' | 'system' | 'local'
   visible: boolean = true;
+  writable: boolean = true; // 只读日历本中的日程只能查看详情，不能编辑
 }
 
 /** 与 UI 无关的调色板 */
@@ -81,7 +84,8 @@ export class AccountStore {
       acc.calendarHrefs.join(';'),
       acc.calendarNames.join(';'),
       acc.calendarColors.join(';'),
-      safe(acc.id)
+      safe(acc.id),
+      acc.calendarWritable.join(';')
     ];
     return parts.join('|');
   }
@@ -109,6 +113,9 @@ export class AccountStore {
     if (parts.length >= 11) {
       acc.id = parts[10];
     }
+    if (parts.length >= 12) {
+      acc.calendarWritable = parts[11] === '' ? [] : parts[11].split(';');
+    }
     return acc;
   }
 

entry/src/main/ets/common/AppSettings.ets

@@ -9,6 +9,83 @@ export class AppSettings {
   private static readonly KEY_SHOW_SYSTEM: string = 'show_system_calendar';
   private static readonly KEY_SYNC_INTERVAL: string = 'sync_interval_minutes';
   private static readonly KEY_BACKGROUND_SYNC: string = 'background_sync';
+  private static readonly KEY_SYS_MODE: string = 'sys_cal_mode';       // 'display' | 'backup'
+  private static readonly KEY_BACKUP_KEY: string = 'sys_backup_cal_key'; // 备份目标 DAV 日历本
+  private static readonly KEY_MANUAL_READONLY: string = 'manual_readonly_keys'; // 手动标记只读的 calKey
+
+  /**
+   * 手动标记为只读的日历本 calKey 列表。
+   * 部分服务器（如群晖某些共享方式）不在 CalDAV 层拒绝写入，自动探测无法区分，
+   * 由用户手动标记，标记后其中日程只显示详情、不出现在新建日程选择中。
+   */
+  static async getManualReadonlyKeys(context: common.Context): Promise<string[]> {
+    try {
+      const store: preferences.Preferences =
+        await preferences.getPreferences(context, AppSettings.STORE);
+      const raw: string = await store.get(AppSettings.KEY_MANUAL_READONLY, '') as string;
+      return raw === '' ? [] : raw.split(';');
+    } catch (err) {
+      return [];
+    }
+  }
+
+  static async setManualReadonlyKeys(context: common.Context, keys: string[]): Promise<void> {
+    try {
+      const store: preferences.Preferences =
+        await preferences.getPreferences(context, AppSettings.STORE);
+      await store.put(AppSettings.KEY_MANUAL_READONLY, keys.join(';'));
+      await store.flush();
+    } catch (err) {
+      const e = err as BusinessError;
+      console.error(`保存手动只读标记失败: ${e.message}`);
+    }
+  }
+
+  /** 系统日历模式：display = 仅混合显示；backup = 本地系统日程备份到选定 CalDAV 日历本 */
+  static async getSysCalMode(context: common.Context): Promise<string> {
+    try {
+      const store: preferences.Preferences =
+        await preferences.getPreferences(context, AppSettings.STORE);
+      return await store.get(AppSettings.KEY_SYS_MODE, 'display') as string;
+    } catch (err) {
+      return 'display';
+    }
+  }
+
+  static async setSysCalMode(context: common.Context, mode: string): Promise<void> {
+    try {
+      const store: preferences.Preferences =
+        await preferences.getPreferences(context, AppSettings.STORE);
+      await store.put(AppSettings.KEY_SYS_MODE, mode);
+      await store.flush();
+    } catch (err) {
+      const e = err as BusinessError;
+      console.error(`保存系统日历模式失败: ${e.message}`);
+    }
+  }
+
+  /** 备份目标日历本 calKey（accId_序号），空 = 未选择 */
+  static async getBackupCalKey(context: common.Context): Promise<string> {
+    try {
+      const store: preferences.Preferences =
+        await preferences.getPreferences(context, AppSettings.STORE);
+      return await store.get(AppSettings.KEY_BACKUP_KEY, '') as string;
+    } catch (err) {
+      return '';
+    }
+  }
+
+  static async setBackupCalKey(context: common.Context, calKey: string): Promise<void> {
+    try {
+      const store: preferences.Preferences =
+        await preferences.getPreferences(context, AppSettings.STORE);
+      await store.put(AppSettings.KEY_BACKUP_KEY, calKey);
+      await store.flush();
+    } catch (err) {
+      const e = err as BusinessError;
+      console.error(`保存备份目标失败: ${e.message}`);
+    }
+  }
 
   /** 是否开启后台持续同步（长时任务，默认关） */
   static async getBackgroundSync(context: common.Context): Promise<boolean> {

entry/src/main/ets/common/CalendarDataService.ets

@@ -25,6 +25,7 @@ export class DisplayEvent {
   color: string = '#007DFF';
   completed: boolean = false; // 仅待办使用
   recurring: boolean = false; // 是否为重复日程展开出的发生
+  writable: boolean = true;   // 所属日历本是否可写（只读时点击显示详情而非编辑）
 }
 
 export class CalendarDataService {
@@ -53,6 +54,7 @@ export class CalendarDataService {
   /** 收集全部日历来源：DAV 日历本 + 本机 + 系统日历账户 */
   static async loadSources(context: common.Context): Promise<CalSource[]> {
     const sources: CalSource[] = [];
+    const manualKeys: string[] = await AppSettings.getManualReadonlyKeys(context);
     try {
       const accounts: DavAccount[] = await AccountStore.loadAll(context);
       for (const acc of accounts) {
@@ -69,6 +71,10 @@ export class CalendarDataService {
           s.color = color !== '' ? color : BookPalette.colorFor(i);
           s.source = 'dav';
           s.visible = true;
+          // 写权限：服务器探测结果 + 手动标记（部分服务器不在 CalDAV 层拒绝写入）
+          const detected: boolean = acc.calendarWritable.length > i
+            ? acc.calendarWritable[i] !== '0' : true;
+          s.writable = detected && !manualKeys.includes(s.calKey);
           sources.push(s);
         }
       }
@@ -142,6 +148,10 @@ export class CalendarDataService {
       const found = sources.find((s: CalSource): boolean => s.calKey === key);
       return found !== undefined ? found.name : '';
     };
+    const writableOf = (key: string): boolean => {
+      const found = sources.find((s: CalSource): boolean => s.calKey === key);
+      return found !== undefined ? found.writable : true;
+    };
 
     // 1) 本地库（DAV + 本机）；重复日程(RRULE)按规则展开为窗口内的多次发生
     try {
@@ -202,6 +212,7 @@ export class CalendarDataService {
           d.calName = baseName;
           d.color = baseColor;
           d.recurring = e.rrule !== '';
+          d.writable = writableOf(e.calKey);
           result.push(d);
           occTotal++;
         }

entry/src/main/ets/common/DavClient.ets

@@ -12,10 +12,12 @@ export class RemoteItem {
   ics: string = '';    // VCALENDAR 文本
 }
 
-/** PROPFIND 返回的集合颜色 */
+/** PROPFIND 返回的集合颜色与写权限 */
 export class DavColorEntry {
   href: string = '';   // 集合路径（服务器返回的是路径，不带域名）
   color: string = '';  // 规范化后的 #RRGGBB，可能为空
+  writable: boolean = true; // current-user-privilege 是否含 write 权限（默认可写）
+  privilegeKnown: boolean = false; // 服务器是否返回了 current-user-privilege-set（未返回时需要写探测）
 }
 
 export class DavClient {
@@ -28,6 +30,7 @@ export class DavClient {
       '<d:propfind xmlns:d="DAV:" xmlns:cs="http://calendarserver.org/ns/" ' +
       'xmlns:ical="http://apple.com/ns/ical/"><d:prop>' +
       '<d:resourcetype/><cs:getcolor/><ical:calendar-color/>' +
+      '<d:current-user-privilege-set/>' +
       '</d:prop></d:propfind>';
     const httpRequest = http.createHttp();
     try {
@@ -71,6 +74,13 @@ export class DavClient {
           color = DavClient.normalizeHex(DavClient.extractTag(block, 'calendar-color'));
         }
         entry.color = color;
+        // 写权限：current-user-privilege-set 存在且不含任何 write 权限 → 只读
+        const privSet: string = DavClient.extractTag(block, 'current-user-privilege-set');
+        if (privSet !== '') {
+          entry.privilegeKnown = true;
+          entry.writable = /write/i.test(privSet);
+          LogUtil.write(`PROPFIND ${href} 权限声明：${privSet.replace(/\s+/g, '').substring(0, 150)}`);
+        }
         result.push(entry);
       }
       if (result.length > 0 && result.every((e: DavColorEntry): boolean => e.color === '')) {
@@ -100,6 +110,61 @@ export class DavClient {
     return 'Basic ' + buffer.from(`${username}:${password}`).toString('base64');
   }
 
+  /**
+   * 写权限探测：向日历本 PUT 一个探测资源——
+   * 2xx → 可写（随后删除探测资源）；403/401 等 → 只读；网络异常 → 乐观按可写。
+   * 用于服务器不返回 current-user-privilege-set 的情况（如部分 Synology 配置）。
+   */
+  static async probeWritable(href: string, auth: string): Promise<boolean> {
+    const url: string = href.endsWith('/')
+      ? `${href}synccalendar-probe.ics` : `${href}/synccalendar-probe.ics`;
+    const ics: string = 'BEGIN:VCALENDAR\r\n' +
+      'VERSION:2.0\r\n' +
+      'PRODID:-//SyncCalendar//Probe//CN\r\n' +
+      'BEGIN:VEVENT\r\n' +
+      'UID:syncprobe\r\n' +
+      'DTSTAMP:20000101T000000Z\r\n' +
+      'DTSTART:20000101T000000Z\r\n' +
+      'DTEND:20000101T010000Z\r\n' +
+      'SUMMARY:probe\r\n' +
+      'END:VEVENT\r\n' +
+      'END:VCALENDAR\r\n';
+    const httpRequest = http.createHttp();
+    try {
+      const resp: http.HttpResponse = await httpRequest.request(url, {
+        method: http.RequestMethod.PUT,
+        header: {
+          'Authorization': auth,
+          'Content-Type': 'text/calendar; charset=utf-8',
+          'User-Agent': 'SyncCalendar/1.0'
+        },
+        extraData: ics,
+        connectTimeout: 10000,
+        readTimeout: 15000
+      });
+      LogUtil.write(`HTTP PUT(探测) ${url} → ${resp.responseCode}`);
+      if (resp.responseCode >= 200 && resp.responseCode < 300) {
+        // 写入成功：删除探测资源，避免污染日历本
+        try {
+          await DavClient.deleteRemote(url, auth);
+        } catch (err) {
+          // 删除失败不影响权限判定
+        }
+        return true;
+      }
+      if (resp.responseCode === 412 || resp.responseCode === 405 || resp.responseCode === 409) {
+        // 资源已存在/方法冲突等：说明有写权限
+        return true;
+      }
+      return false; // 403/401 等 → 只读
+    } catch (err) {
+      // 网络异常无法判定：乐观按可写，避免误标只读
+      return true;
+    } finally {
+      httpRequest.destroy();
+    }
+  }
+
   /** REPORT calendar-query：全量拉取某日历本内所有 VEVENT（不加时间范围，保证数据完整） */
   static async reportCalendar(href: string, auth: string): Promise<RemoteItem[]> {
     return DavClient.reportComponents(href, auth, 'VEVENT', '');

entry/src/main/ets/common/EventDb.ets

@@ -409,6 +409,17 @@ export class EventDb {
     return `新增${added} 更新${updated} 删除${removed} 不变${unchanged}`;
   }
 
+  /** 按 UID 判断事件是否已存在（系统日历备份导入的幂等判重） */
+  static async uidExists(context: common.Context, uid: string): Promise<boolean> {
+    const store = await EventDb.getDb(context);
+    const predicates = new relationalStore.RdbPredicates('events');
+    predicates.equalTo('uid', uid);
+    const rs = await store.query(predicates);
+    const exists: boolean = rs.rowCount > 0;
+    rs.close();
+    return exists;
+  }
+
   /** 删除某账号全部本地事件（删除账号时调用） */
   static async deleteAccountEvents(context: common.Context, accId: string): Promise<void> {
     const store = await EventDb.getDb(context);

entry/src/main/ets/common/IcsUtil.ets

@@ -240,13 +240,32 @@ export class IcsUtil {
       `DTSTAMP:${now}\r\n` +
       `${dtstart}\r\n` +
       `${dtend}\r\n` +
+      (e.rrule !== '' ? `RRULE:${e.rrule}\r\n` : '') +
       `SUMMARY:${IcsUtil.escape(e.title)}\r\n` +
       (e.location !== '' ? `LOCATION:${IcsUtil.escape(e.location)}\r\n` : '') +
       (e.description !== '' ? `DESCRIPTION:${IcsUtil.escape(e.description)}\r\n` : '') +
+      (e.reminder > 0 ? IcsUtil.valarm(e.reminder) : '') +
       'END:VEVENT\r\n' +
       'END:VCALENDAR\r\n';
   }
 
+  /** 由提前分钟数生成 VALARM（TRIGGER 负时长 = 提前触发） */
+  private static valarm(minutes: number): string {
+    let trigger: string;
+    if (minutes >= 1440 && minutes % 1440 === 0) {
+      trigger = `-P${minutes / 1440}D`;
+    } else if (minutes >= 60 && minutes % 60 === 0) {
+      trigger = `-PT${minutes / 60}H`;
+    } else {
+      trigger = `-PT${minutes}M`;
+    }
+    return 'BEGIN:VALARM\r\n' +
+      `TRIGGER:${trigger}\r\n` +
+      'ACTION:DISPLAY\r\n' +
+      'DESCRIPTION:提醒\r\n' +
+      'END:VALARM\r\n';
+  }
+
   static escape(s: string): string {
     return s.replace(/\\/g, '\\\\').replace(/;/g, '\\;').replace(/,/g, '\\,').replace(/\n/g, '\\n');
   }

entry/src/main/ets/common/SyncEngine.ets

@@ -70,6 +70,9 @@ export class SyncEngine {
         }
         // 一个资源可能包含主事件 + 单次覆盖实例（RECURRENCE-ID），全部入库
         for (const r of parsed) {
+          if (r.uid === 'syncprobe') {
+            continue; // 写权限探测资源（万一删除失败），不入库展示
+          }
           if (r.uid === '') {
             r.uid = SyncEngine.uidFromHref(it.href);
           }
@@ -113,31 +116,44 @@ export class SyncEngine {
    * 失败静默（颜色不影响数据正确性）
    */
   static async refreshCalendarColors(acc: DavAccount, auth: string): Promise<void> {
+    let entries: DavColorEntry[] = [];
     try {
-      const entries: DavColorEntry[] = await DavClient.propfindColors(acc.serverUrl, auth);
-      if (entries.length === 0) {
-        return;
-      }
-      for (let i = 0; i < acc.calendarHrefs.length; i++) {
-        const target: string = acc.calendarHrefs[i];
-        const originMatch = /https?:\/\/[^/]+/i.exec(target);
-        let path: string = originMatch !== null ? target.substring(originMatch[0].length) : target;
-        if (path === '') {
-          path = '/';
-        }
-        const norm = (s: string): string => s.endsWith('/') ? s : s + '/';
-        const found = entries.find((e: DavColorEntry): boolean =>
-          norm(e.href) === norm(path));
-        if (found !== undefined && found.color !== '') {
-          while (acc.calendarColors.length <= i) {
-            acc.calendarColors.push('');
-          }
-          acc.calendarColors[i] = found.color;
-        }
-      }
+      entries = await DavClient.propfindColors(acc.serverUrl, auth);
     } catch (err) {
       const e = err as BusinessError;
-      console.info(`刷新日历本颜色失败(忽略): ${e.message}`);
+      LogUtil.write(`PROPFIND 颜色/权限失败(继续探测写权限): ${e.message}`);
+    }
+    for (let i = 0; i < acc.calendarHrefs.length; i++) {
+      const target: string = acc.calendarHrefs[i];
+      const originMatch = /https?:\/\/[^/]+/i.exec(target);
+      let path: string = originMatch !== null ? target.substring(originMatch[0].length) : target;
+      if (path === '') {
+        path = '/';
+      }
+      const norm = (s: string): string => s.endsWith('/') ? s : s + '/';
+      const found = entries.find((e: DavColorEntry): boolean =>
+        norm(e.href) === norm(path));
+      if (found !== undefined && found.color !== '') {
+        while (acc.calendarColors.length <= i) {
+          acc.calendarColors.push('');
+        }
+        acc.calendarColors[i] = found.color;
+      }
+      // 回写各日历本写权限（'1'=可写 '0'=只读）
+      while (acc.calendarWritable.length <= i) {
+        acc.calendarWritable.push('1');
+      }
+      const calName: string = i < acc.calendarNames.length ? acc.calendarNames[i] : `日历本${i}`;
+      if (found !== undefined && found.privilegeKnown) {
+        // 服务器声明了权限：直接采用
+        acc.calendarWritable[i] = found.writable ? '1' : '0';
+        LogUtil.write(`日历本[${i}]「${calName}」写权限(privilege)：${found.writable ? '可写' : '只读'}`);
+      } else {
+        // 服务器未声明权限（如部分 Synology 配置）或 PROPFIND 未匹配到该本：真实写探测
+        const w: boolean = await DavClient.probeWritable(target, auth);
+        acc.calendarWritable[i] = w ? '1' : '0';
+        LogUtil.write(`日历本[${i}]「${calName}」写权限(探测)：${w ? '可写' : '只读'}`);
+      }
     }
   }
 
@@ -159,17 +175,28 @@ export class SyncEngine {
     const mine: LocalEvent[] = dirty.filter((e: LocalEvent): boolean => acc.calendarHrefs.includes(e.href));
     LogUtil.write(`推送本地修改：全部待推送 ${dirty.length} 条，属于账号「${acc.name}」的 ${mine.length} 条`);
     for (const e of mine) {
+      // 只读日历本：推送必然 403，跳过并保留 dirty（权限恢复后可再推）
+      const bookIdx: number = acc.calendarHrefs.indexOf(e.href);
+      if (bookIdx >= 0 && acc.calendarWritable.length > bookIdx
+        && acc.calendarWritable[bookIdx] === '0') {
+        LogUtil.write(`推送跳过只读日历本事件「${e.title}」(uid=${e.uid})`);
+        continue;
+      }
       if (e.kind === 'todo') {
         // 待办只读：本地不会有 dirty 待办，兜底清除
         await EventDb.clearDirty(context, e.id, e.etag);
         continue;
       }
-      if (e.recurring) {
-        // 重复日程实例推送会破坏服务器整个序列，暂不支持
+      if (e.recurring && e.rrule === '') {
+        // 重复日程的"单次覆盖实例"（RECURRENCE-ID）推送会破坏服务器整个序列，暂不支持
         await EventDb.clearDirty(context, e.id, e.etag);
         LogUtil.write(`推送跳过重复日程实例「${e.title}」(uid=${e.uid})`);
         continue;
       }
+      if (e.recurring) {
+        // 重复主事件（含 RRULE，含本机新建的重复日程）：整条 PUT 覆盖推送
+        LogUtil.write(`推送重复主事件「${e.title}」(uid=${e.uid})`);
+      }
       const url: string = e.href.endsWith('/') ? e.href + e.remotePath : `${e.href}/${e.remotePath}`;
       if (e.deleted) {
         await DavClient.deleteRemote(url, auth);

entry/src/main/ets/common/SystemCalendarImport.ets

@@ -0,0 +1,121 @@
+// entry/src/main/ets/common/SystemCalendarImport.ets
+// 系统日历备份：把手机"本地"系统日历（非 CalDAV 同步日历）的全部日程导入
+// 用户选定的 CalDAV 日历本（置 dirty 待推送），随后随同步上传服务器。
+// 价值：手机丢失/换机后，系统日历日程在用户自己的 CalDAV 服务器上仍有备份。
+import { common } from '@kit.AbilityKit';
+import { calendarManager } from '@kit.CalendarKit';
+import { BusinessError } from '@kit.BasicServicesKit';
+import { AccountStore, DavAccount } from './AccountStore';
+import { EventDb, LocalEvent } from './EventDb';
+import { AppSettings } from './AppSettings';
+import { LogUtil } from './LogUtil';
+
+export class SystemCalendarImport {
+  /**
+   * 备份模式下的导入入口（display 模式直接返回 0）。
+   * 幂等：uid = syscal-<系统日历id>-<事件id>，已存在则跳过，因此每次同步都可安全执行。
+   * 只读取 calendarType = LOCAL 的系统日历（手机本地日历/应用创建的日程），
+   * 系统 CalDAV 同步产生的账户日历一律跳过，避免死循环回灌。
+   */
+  static async importIfNeeded(context: common.Context): Promise<number> {
+    try {
+      const mode: string = await AppSettings.getSysCalMode(context);
+      if (mode !== 'backup') {
+        return 0;
+      }
+      const calKey: string = await AppSettings.getBackupCalKey(context);
+      if (calKey === '') {
+        LogUtil.write('系统日历备份：未选择目标日历本，跳过导入');
+        return 0;
+      }
+      // 定位目标 CalDAV 日历本
+      const accounts: DavAccount[] = await AccountStore.loadAll(context);
+      let targetHref: string = '';
+      for (const acc of accounts) {
+        for (let i = 0; i < acc.calendarHrefs.length; i++) {
+          if (`${acc.id}_${i}` === calKey) {
+            targetHref = acc.calendarHrefs[i];
+          }
+        }
+      }
+      if (targetHref === '') {
+        LogUtil.write(`系统日历备份：目标日历本 ${calKey} 不存在（账号可能已删除），跳过导入`);
+        return 0;
+      }
+      const uiContext = context as common.UIAbilityContext;
+      const mgr: calendarManager.CalendarManager = calendarManager.getCalendarManager(uiContext);
+      const calendars: calendarManager.Calendar[] = await mgr.getAllCalendars();
+      let imported: number = 0;
+      let skippedCal: number = 0;
+      for (const cal of calendars) {
+        try {
+          // 只处理"本地"类型系统日历；CalDAV/订阅等账户日历的数据源本来就在服务器上，跳过防回灌
+          const account: calendarManager.CalendarAccount = cal.getAccount();
+          if (account.type !== calendarManager.CalendarType.LOCAL) {
+            skippedCal++;
+            continue;
+          }
+          const events: calendarManager.Event[] = await cal.getEvents();
+          for (const ev of events) {
+            if (ev.id === undefined) {
+              continue;
+            }
+            const uid: string = `syscal-${account.name}-${ev.id}`;
+            if (await EventDb.uidExists(context, uid)) {
+              continue;
+            }
+            const e = new LocalEvent();
+            e.uid = uid;
+            e.calKey = calKey;
+            e.href = targetHref;
+            e.remotePath = encodeURIComponent(uid) + '.ics';
+            e.title = ev.title !== undefined ? ev.title : '';
+            e.description = ev.description !== undefined ? ev.description : '';
+            e.location = ev.location !== undefined && ev.location.location !== undefined
+              ? ev.location.location : '';
+            e.startTime = ev.startTime;
+            e.endTime = ev.endTime;
+            e.isAllDay = ev.isAllDay === true;
+            e.kind = 'event';
+            e.rrule = SystemCalendarImport.rruleOf(ev);
+            e.recurring = e.rrule !== '';
+            await EventDb.insertLocal(context, e); // insertLocal 置 dirty，随同步推送
+            imported++;
+          }
+        } catch (err) {
+          // 单个日历读取失败不影响其余
+        }
+      }
+      if (imported > 0 || skippedCal > 0) {
+        LogUtil.write(`系统日历备份：新增 ${imported} 条 → ${calKey}（跳过账户日历 ${skippedCal} 个）`);
+      }
+      return imported;
+    } catch (err) {
+      const e = err as BusinessError;
+      LogUtil.write(`系统日历备份导入失败(忽略): ${e.message}`);
+      return 0;
+    }
+  }
+
+  /** 系统日程的 recurrenceRule → 尽力转换的 RRULE 字符串（仅 FREQ/INTERVAL，复杂规则服务器端可再完善） */
+  private static rruleOf(ev: calendarManager.Event): string {
+    try {
+      const rr = ev.recurrenceRule;
+      if (rr === undefined) {
+        return '';
+      }
+      const freqMap: string[] = ['YEARLY', 'MONTHLY', 'WEEKLY', 'DAILY'];
+      const fi: number = rr.recurrenceFrequency as number;
+      if (Number.isNaN(fi) || fi < 0 || fi >= freqMap.length) {
+        return '';
+      }
+      let rrule: string = `FREQ=${freqMap[fi]}`;
+      if (rr.interval !== undefined && rr.interval > 1) {
+        rrule += `;INTERVAL=${rr.interval}`;
+      }
+      return rrule;
+    } catch (err) {
+      return '';
+    }
+  }
+}

entry/src/main/ets/entryability/EntryAbility.ets

@@ -1,6 +1,7 @@
 import { AbilityConstant, ConfigurationConstant, UIAbility, Want } from '@kit.AbilityKit';
 import { hilog } from '@kit.PerformanceAnalysisKit';
 import { window } from '@kit.ArkUI';
+import { BusinessError } from '@kit.BasicServicesKit';
 import { BackgroundSyncService } from '../common/BackgroundSyncService';
 
 const DOMAIN = 0x0000;
@@ -24,6 +25,27 @@ export default class EntryAbility extends UIAbility {
         return;
       }
       hilog.info(DOMAIN, 'testTag', 'Succeeded in loading the content.');
+      // 沉浸式配色：状态栏/导航条与页面背景同色（app.color.page_bg = #F1F3F5），
+      // 消除顶部通知栏和底部的白色条
+      windowStage.getMainWindow((werr: BusinessError, win: window.Window) => {
+        if (werr.code) {
+          hilog.error(DOMAIN, 'testTag', 'Failed to get main window. Cause: %{public}s', JSON.stringify(werr));
+          return;
+        }
+        try {
+          win.setWindowSystemBarProperties({
+            statusBarColor: '#F1F3F5',
+            statusBarContentColor: '#182431',
+            navigationBarColor: '#F1F3F5',
+            navigationBarContentColor: '#182431'
+          });
+          // 鸿蒙 NEXT 导航条背景跟随窗口背景色：设为页面背景灰，消除底部白条
+          win.setWindowBackgroundColor('#F1F3F5');
+        } catch (barErr) {
+          hilog.error(DOMAIN, 'testTag', 'Failed to set system bar properties. Cause: %{public}s',
+            JSON.stringify(barErr));
+        }
+      });
     });
     try {
       this.context.getApplicationContext().setColorMode(ConfigurationConstant.ColorMode.COLOR_MODE_NOT_SET);

entry/src/main/ets/pages/EventEditPage.ets

@@ -5,6 +5,7 @@ import { common } from '@kit.AbilityKit';
 import { BusinessError } from '@kit.BasicServicesKit';
 import { DavAccount, AccountStore, CalSource, BookPalette } from '../common/AccountStore';
 import { EventDb, LocalEvent } from '../common/EventDb';
+import { AppSettings } from '../common/AppSettings';
 import { DavClient } from '../common/DavClient';
 import { SyncEngine } from '../common/SyncEngine';
 
@@ -30,6 +31,13 @@ struct EventEditPage {
   @State isSaving: boolean = false;
   @State statusMsg: string = '';
   @State isExisting: boolean = false;
+  @State repeatMode: string = 'none'; // none|daily|workday|weekly|monthly|yearly|custom
+  @State reminderMin: number = 0;    // 提前提醒分钟数，0 = 不提醒
+  @State pickerShow: boolean = false; // 开始/结束时间选择底部弹层（日期+时间一次选完）
+  @State pickerIsEnd: boolean = false;
+  @State pickDate: Date = new Date();
+  @State pickHour: number = 9;
+  @State pickMin: number = 0;
   private event: LocalEvent | null = null;
 
   aboutToAppear(): Promise<void> {
@@ -41,7 +49,7 @@ struct EventEditPage {
     if (context === undefined) {
       return;
     }
-    // 收集可写入的日历本（DAV + 本机）
+    // 收集可写入的日历本（DAV 可写日历本 + 本机）；只读日历本不出现在新建/编辑选择中
     const sources: CalSourceWithHref[] = await CalendarDataBridge.loadWritableSources(context);
     const choices: BookChoice[] = [];
     for (const s of sources) {
@@ -68,6 +76,8 @@ struct EventEditPage {
         this.startMs = loaded.startTime;
         this.endMs = loaded.endTime;
         this.chosenKey = loaded.calKey;
+        this.repeatMode = loaded.rrule !== '' ? this.modeFromRrule(loaded.rrule) : 'none';
+        this.reminderMin = loaded.reminder;
         return;
       }
     }
@@ -98,62 +108,81 @@ struct EventEditPage {
     return `${p(d.getHours())}:${p(d.getMinutes())}`;
   }
 
-  private pickStartDate(): void {
-    const cur = new Date(this.startMs);
-    DatePickerDialog.show({
-      start: new Date(2000, 0, 1),
-      end: new Date(2050, 11, 31),
-      selected: cur,
-      onDateAccept: (value: Date) => {
-        const keep = new Date(this.startMs);
-        const newStart: number = new Date(value.getFullYear(), value.getMonth(), value.getDate(),
-          keep.getHours(), keep.getMinutes()).getTime();
-        const dur: number = this.endMs - this.startMs;
-        this.startMs = newStart;
-        this.endMs = this.allDay ? newStart + 86399999 : newStart + dur;
-      }
-    });
+  /** 重复模式 → RRULE 字符串（RruleUtil 已支持这些规则） */
+  private rruleForMode(mode: string): string {
+    if (mode === 'daily') {
+      return 'FREQ=DAILY';
+    }
+    if (mode === 'workday') {
+      return 'FREQ=WEEKLY;BYDAY=MO,TU,WE,TH,FR';
+    }
+    if (mode === 'weekly') {
+      return 'FREQ=WEEKLY';
+    }
+    if (mode === 'monthly') {
+      return 'FREQ=MONTHLY';
+    }
+    if (mode === 'yearly') {
+      return 'FREQ=YEARLY';
+    }
+    return '';
   }
 
-  private pickStartTime(): void {
-    const cur = new Date(this.startMs);
-    TimePickerDialog.show({
-      selected: cur,
-      onAccept: (value: TimePickerResult) => {
-        const d = new Date(this.startMs);
-        const newStart: number = new Date(d.getFullYear(), d.getMonth(), d.getDate(),
-          value.hour, value.minute).getTime();
-        const dur: number = this.endMs - this.startMs;
-        this.startMs = newStart;
-        this.endMs = newStart + dur;
-      }
-    });
+  /** RRULE → 重复模式（无法识别的规则归为 custom，保存时保留原规则） */
+  private modeFromRrule(rrule: string): string {
+    const u: string = rrule.toUpperCase();
+    if (u.includes('FREQ=DAILY')) {
+      return 'daily';
+    }
+    if (u.includes('FREQ=WEEKLY')) {
+      const hasWeekday: boolean = u.includes('MO') && u.includes('TU') && u.includes('WE')
+        && u.includes('TH') && u.includes('FR');
+      return hasWeekday ? 'workday' : 'weekly';
+    }
+    if (u.includes('FREQ=MONTHLY')) {
+      return 'monthly';
+    }
+    if (u.includes('FREQ=YEARLY')) {
+      return 'yearly';
+    }
+    return 'custom';
   }
 
-  private pickEndDate(): void {
-    const cur = new Date(this.endMs);
-    DatePickerDialog.show({
-      start: new Date(2000, 0, 1),
-      end: new Date(2050, 11, 31),
-      selected: cur,
-      onDateAccept: (value: Date) => {
-        const keep = new Date(this.endMs);
-        this.endMs = new Date(value.getFullYear(), value.getMonth(), value.getDate(),
-          keep.getHours(), keep.getMinutes()).getTime();
-      }
-    });
+  private reminderLabel(m: number): string {
+    if (m === 0) {
+      return '不提醒';
+    }
+    if (m < 60) {
+      return `提前${m}分钟`;
+    }
+    if (m < 1440) {
+      return `提前${m / 60}小时`;
+    }
+    return `提前${m / 1440}天`;
   }
 
-  private pickEndTime(): void {
-    const cur = new Date(this.endMs);
-    TimePickerDialog.show({
-      selected: cur,
-      onAccept: (value: TimePickerResult) => {
-        const d = new Date(this.endMs);
-        this.endMs = new Date(d.getFullYear(), d.getMonth(), d.getDate(),
-          value.hour, value.minute).getTime();
-      }
-    });
+  /** 打开时间选择弹层：日期 + 时间一次选完 */
+  private openPicker(isEnd: boolean): void {
+    this.pickerIsEnd = isEnd;
+    const base = new Date(isEnd ? this.endMs : this.startMs);
+    this.pickDate = new Date(base.getFullYear(), base.getMonth(), base.getDate());
+    this.pickHour = base.getHours();
+    this.pickMin = base.getMinutes();
+    this.pickerShow = true;
+  }
+
+  private applyPicker(): void {
+    const d = this.pickDate;
+    const picked: number = new Date(d.getFullYear(), d.getMonth(), d.getDate(),
+      this.pickHour, this.pickMin).getTime();
+    if (this.pickerIsEnd) {
+      // 全天日程的结束存为"当天 23:59:59.999"（排他日期前 1 毫秒）
+      this.endMs = this.allDay ? picked + 86399999 : picked;
+    } else {
+      const dur: number = Math.max(0, this.endMs - this.startMs);
+      this.startMs = picked;
+      this.endMs = this.allDay ? picked + 86399999 : picked + dur;
+    }
   }
 
   private toggleAllDay(): void {
@@ -186,8 +215,9 @@ struct EventEditPage {
     if (this.isSaving || !this.validate()) {
       return;
     }
-    if (this.event !== null && this.event.recurring) {
-      this.statusMsg = '重复日程（系列中的一天）暂不支持修改，请到服务器端调整重复规则';
+    // 仅阻止"单次覆盖实例"（RECURRENCE-ID）的修改；重复主事件（含 RRULE）允许编辑
+    if (this.event !== null && this.event.recurring && this.event.rrule === '') {
+      this.statusMsg = '重复日程的单次修改暂不支持，请到服务器端调整重复规则';
       return;
     }
     this.isSaving = true;
@@ -208,6 +238,15 @@ struct EventEditPage {
       e.isAllDay = this.allDay;
       e.calKey = book !== null ? book.calKey : 'local';
       e.href = book !== null ? book.href : '';
+      // 重复规则与提醒
+      if (this.repeatMode === 'custom') {
+        // 无法识别的既有规则原样保留
+        e.rrule = this.event !== null ? this.event.rrule : '';
+      } else {
+        e.rrule = this.rruleForMode(this.repeatMode);
+      }
+      e.recurring = e.rrule !== '';
+      e.reminder = this.reminderMin;
       if (isNew) {
         e.uid = `syncal-${Date.now()}-${Math.floor(Math.random() * 1000000)}`;
         e.remotePath = encodeURIComponent(e.uid) + '.ics';
@@ -242,8 +281,8 @@ struct EventEditPage {
     if (this.event === null || this.isSaving) {
       return;
     }
-    if (this.event.recurring) {
-      this.statusMsg = '重复日程（系列中的一天）暂不支持删除，请到服务器端调整重复规则';
+    if (this.event !== null && this.event.recurring && this.event.rrule === '') {
+      this.statusMsg = '重复日程的单次删除暂不支持，请到服务器端调整重复规则';
       return;
     }
     this.isSaving = true;
@@ -274,11 +313,12 @@ struct EventEditPage {
 
   build() {
     Column({ space: 14 }) {
-      // 顶部
+      // 顶部（与内容区左右对齐，避免贴边误触）
       Row({ space: 6 }) {
         Text('取消')
           .fontSize(16)
           .fontColor($r('app.color.brand'))
+          .padding({ left: 4, right: 4, top: 8, bottom: 8 })
           .onClick(() => {
             router.back();
           })
@@ -292,11 +332,13 @@ struct EventEditPage {
           .fontSize(16)
           .fontColor(this.isSaving ? $r('app.color.text_hint') : $r('app.color.brand'))
           .fontWeight(FontWeight.Medium)
+          .padding({ left: 4, right: 4, top: 8, bottom: 8 })
           .onClick(() => {
             this.save();
           })
       }
       .width('100%')
+      .padding({ left: 16, right: 16 })
 
       Scroll() {
         Column({ space: 14 }) {
@@ -327,7 +369,7 @@ struct EventEditPage {
           .borderRadius(12)
           .backgroundColor($r('app.color.card_bg'))
 
-          // 时间卡片
+          // 时间卡片（单击任一行：底部弹层中日期+时间一次选完）
           Column({ space: 10 }) {
             this.timeRow('开始', true)
             Divider().color($r('app.color.shadow_color'))
@@ -338,6 +380,53 @@ struct EventEditPage {
           .borderRadius(12)
           .backgroundColor($r('app.color.card_bg'))
 
+          // 重复
+          Column({ space: 8 }) {
+            Text('重复')
+              .fontSize(14)
+              .fontColor($r('app.color.text_secondary'))
+            Flex({ wrap: FlexWrap.Wrap, justifyContent: FlexAlign.Start }) {
+              this.repeatChip('none', '不重复')
+              this.repeatChip('daily', '每天')
+              this.repeatChip('workday', '工作日')
+              this.repeatChip('weekly', '每周')
+              this.repeatChip('monthly', '每月')
+              this.repeatChip('yearly', '每年')
+              if (this.repeatMode === 'custom') {
+                // 服务器来的复杂规则（INTERVAL/COUNT 等）标记为自定义，保存时原样保留
+                this.repeatChip('custom', '自定义')
+              }
+            }
+            .width('100%')
+          }
+          .alignItems(HorizontalAlign.Start)
+          .width('100%')
+          .padding(14)
+          .borderRadius(12)
+          .backgroundColor($r('app.color.card_bg'))
+
+          // 提醒
+          Column({ space: 8 }) {
+            Text('提醒')
+              .fontSize(14)
+              .fontColor($r('app.color.text_secondary'))
+            Flex({ wrap: FlexWrap.Wrap, justifyContent: FlexAlign.Start }) {
+              this.reminderChip(0)
+              this.reminderChip(5)
+              this.reminderChip(10)
+              this.reminderChip(15)
+              this.reminderChip(30)
+              this.reminderChip(60)
+              this.reminderChip(1440)
+            }
+            .width('100%')
+          }
+          .alignItems(HorizontalAlign.Start)
+          .width('100%')
+          .padding(14)
+          .borderRadius(12)
+          .backgroundColor($r('app.color.card_bg'))
+
           // 日历本选择
           Column({ space: 8 }) {
             Text('日历本')
@@ -424,6 +513,12 @@ struct EventEditPage {
     .height('100%')
     .padding({ top: 12 })
     .backgroundColor($r('app.color.page_bg'))
+    .bindSheet($$this.pickerShow, this.dateTimePickerSheet(), {
+      height: 380,
+      showClose: false,
+      dragBar: true,
+      backgroundColor: $r('app.color.card_bg')
+    })
   }
 
   @Builder
@@ -433,32 +528,102 @@ struct EventEditPage {
         .fontSize(14)
         .fontColor($r('app.color.text_secondary'))
         .width(36)
-      Text(this.fmtDate(isStart ? this.startMs : this.endMs))
+      Text(this.allDay
+        ? this.fmtDate(isStart ? this.startMs : this.endMs)
+        : `${this.fmtDate(isStart ? this.startMs : this.endMs)} ${this.fmtTime(isStart ? this.startMs : this.endMs)}`)
         .fontSize(15)
         .fontColor($r('app.color.brand'))
-        .onClick(() => {
-          if (isStart) {
-            this.pickStartDate();
-          } else {
-            this.pickEndDate();
-          }
-        })
-      if (!this.allDay) {
-        Text(this.fmtTime(isStart ? this.startMs : this.endMs))
-          .fontSize(15)
-          .fontColor($r('app.color.brand'))
-          .onClick(() => {
-            if (isStart) {
-              this.pickStartTime();
-            } else {
-              this.pickEndTime();
-            }
-          })
-      }
-      Blank()
+        .layoutWeight(1)
+      Text('›')
+        .fontSize(16)
+        .fontColor($r('app.color.text_hint'))
     }
     .width('100%')
-    .padding({ left: 8, right: 8, top: 8, bottom: 8 })
+    .padding({ left: 8, right: 8, top: 10, bottom: 10 })
+    .onClick(() => {
+      this.openPicker(isStart);
+    })
+  }
+
+  @Builder
+  repeatChip(mode: string, label: string) {
+    Text(label)
+      .fontSize(12)
+      .fontColor(this.repeatMode === mode
+        ? $r('app.color.button_text') : $r('app.color.text_primary'))
+      .padding({ left: 10, right: 10, top: 6, bottom: 6 })
+      .borderRadius(14)
+      .margin({ right: 8, bottom: 8 })
+      .backgroundColor(this.repeatMode === mode ? $r('app.color.brand') : $r('app.color.chip_off_bg'))
+      .onClick(() => {
+        this.repeatMode = mode;
+      })
+  }
+
+  @Builder
+  reminderChip(minutes: number) {
+    Text(this.reminderLabel(minutes))
+      .fontSize(12)
+      .fontColor(this.reminderMin === minutes
+        ? $r('app.color.button_text') : $r('app.color.text_primary'))
+      .padding({ left: 10, right: 10, top: 6, bottom: 6 })
+      .borderRadius(14)
+      .margin({ right: 8, bottom: 8 })
+      .backgroundColor(this.reminderMin === minutes ? $r('app.color.brand') : $r('app.color.chip_off_bg'))
+      .onClick(() => {
+        this.reminderMin = minutes;
+      })
+  }
+
+  /** 开始/结束时间选择弹层：左侧日期、右侧时间（全天时只有日期），一次确定 */
+  @Builder
+  dateTimePickerSheet() {
+    Column({ space: 14 }) {
+      Text(this.pickerIsEnd ? '选择结束时间' : '选择开始时间')
+        .fontSize(16)
+        .fontWeight(FontWeight.Bold)
+        .fontColor($r('app.color.text_primary'))
+        .width('100%')
+        .textAlign(TextAlign.Center)
+        .padding({ top: 12 })
+      Row({ space: 6 }) {
+        DatePicker({
+          start: new Date(2000, 0, 1),
+          end: new Date(2050, 11, 31),
+          selected: this.pickDate
+        })
+          .onDateChange((value: Date) => {
+            this.pickDate = value;
+          })
+          .layoutWeight(1)
+          .height(210)
+        if (!this.allDay) {
+          TimePicker({
+            selected: new Date(2000, 0, 1, this.pickHour, this.pickMin)
+          })
+            .onChange((value: TimePickerResult) => {
+              this.pickHour = value.hour;
+              this.pickMin = value.minute;
+            })
+            .layoutWeight(1)
+            .height(210)
+        }
+      }
+      .width('100%')
+
+      Button(this.allDay ? '确定日期' : '确定')
+        .width('100%')
+        .height(44)
+        .borderRadius(12)
+        .fontSize(15)
+        .backgroundColor($r('app.color.brand'))
+        .onClick(() => {
+          this.applyPicker();
+          this.pickerShow = false;
+        })
+    }
+    .width('100%')
+    .padding({ left: 16, right: 16, bottom: 24 })
   }
 }
 
@@ -467,8 +632,15 @@ class CalendarDataBridge {
   static async loadWritableSources(context: common.Context): Promise<CalSourceWithHref[]> {
     const result: CalSourceWithHref[] = [];
     const accounts: DavAccount[] = await AccountStore.loadAll(context);
+    const manualKeys: string[] = await AppSettings.getManualReadonlyKeys(context);
     for (const acc of accounts) {
       for (let i = 0; i < acc.calendarHrefs.length; i++) {
+        // 只读日历本（服务器无写权限，或用户手动标记只读）不可选
+        const detected: boolean = acc.calendarWritable.length > i
+          ? acc.calendarWritable[i] !== '0' : true;
+        if (!detected || manualKeys.includes(`${acc.id}_${i}`)) {
+          continue;
+        }
         const s = new CalSourceWithHref();
         s.calKey = `${acc.id}_${i}`;
         let name: string = i < acc.calendarNames.length ? acc.calendarNames[i] : '';
@@ -479,6 +651,7 @@ class CalendarDataBridge {
         let color: string = i < acc.calendarColors.length ? AccountStore.normalizeColor(acc.calendarColors[i]) : '';
         s.color = color !== '' ? color : BookPalette.colorFor(i);
         s.href = acc.calendarHrefs[i];
+        s.writable = true;
         result.push(s);
       }
     }

entry/src/main/ets/pages/Index.ets

@@ -1,7 +1,7 @@
 // entry/src/main/ets/pages/Index.ets
 // 同步日历主界面：月视图（左右滑动翻月）/ 周视图 / 日视图 / 日程列表
 // 混合展示 DAV 与系统日历；每分钟自动同步；可"回到今天"
-import { router } from '@kit.ArkUI';
+import { mediaquery, router } from '@kit.ArkUI';
 import { common } from '@kit.AbilityKit';
 import { BusinessError, pasteboard } from '@kit.BasicServicesKit';
 import { DavAccount, AccountStore, CalSource, TYPE_CALDAV } from '../common/AccountStore';
@@ -15,6 +15,7 @@ import { AppSettings } from '../common/AppSettings';
 import { EventDb, LocalEvent } from '../common/EventDb';
 import { RruleUtil } from '../common/RruleUtil';
 import { IcsUtil } from '../common/IcsUtil';
+import { SystemCalendarImport } from '../common/SystemCalendarImport';
 
 /** 月视图单元格 */
 class MonthCell {
@@ -43,6 +44,8 @@ struct Index {
   @State syncing: boolean = false;
   @State loading: boolean = true;
   @State menuOpen: boolean = false; // 顶部 ≡ 下拉菜单
+  @State isLandscape: boolean = false; // 横屏：月视图切左右双栏（左月历/右当日日程）
+  private landscapeListener: mediaquery.MediaQueryListener | null = null;
   private accounts: DavAccount[] = [];
   private sources: CalSource[] = [];
   private swiperController: SwiperController = new SwiperController();
@@ -62,6 +65,7 @@ struct Index {
     this.displayMonth = now.getMonth();
     this.selectedDate = this.startOfDay(now.getTime());
     this.rebuildPages();
+    this.initLandscapeListener();
     this.initPermissionAndLoad();
   }
 
@@ -70,6 +74,20 @@ struct Index {
       clearInterval(this.autoSyncTimer);
       this.autoSyncTimer = -1;
     }
+    if (this.landscapeListener !== null) {
+      this.landscapeListener.off('change');
+      this.landscapeListener = null;
+    }
+  }
+
+  /** 监听横竖屏：旋转后 isLandscape 驱动月视图在上下/左右布局间切换 */
+  private initLandscapeListener(): void {
+    this.landscapeListener =
+      this.getUIContext().getMediaQuery().matchMediaSync('(orientation: landscape)');
+    this.isLandscape = this.landscapeListener.matches;
+    this.landscapeListener.on('change', (result: mediaquery.MediaQueryResult) => {
+      this.isLandscape = result.matches;
+    });
   }
 
   /** 从设置页/账号页返回时刷新（同步间隔、系统日历开关立即生效），并处理编辑账号后的待同步 */
@@ -329,6 +347,12 @@ struct Index {
     }
     let ok: number = 0;
     let failMsg: string = '';
+    // 备份模式：先把系统本地日历导入目标日历本（幂等），再随正常同步推送上服务器
+    try {
+      await SystemCalendarImport.importIfNeeded(context);
+    } catch (err) {
+      // 导入失败不影响正常同步
+    }
     for (const acc of this.accounts) {
       if (acc.type !== TYPE_CALDAV) {
         continue;
@@ -373,15 +397,53 @@ struct Index {
   }
 
   private openEvent(e: DisplayEvent): void {
-    if (e.isSystem) {
-      this.getUIContext().getPromptAction()
-        .showToast({ message: '系统日历日程，请在系统日历 App 中编辑' });
+    // 只读日历本或系统日历日程：无法保存修改，直接显示详情
+    if (e.isSystem || !e.writable) {
+      this.showEventDetail(e);
       return;
     }
     AppStorage.setOrCreate<number>('pendingEventId', e.id);
     router.pushUrl({ url: 'pages/EventEditPage' });
   }
 
+  /** 只读日程详情弹窗 */
+  private showEventDetail(e: DisplayEvent): void {
+    const lines: string[] = [];
+    if (e.isAllDay) {
+      lines.push(`时间：全天 ${this.fmtDateCn(e.startTime)}`);
+      if (this.spansDays(e)) {
+        lines.push(`        ~ ${this.fmtDateCn(e.endTime)}`);
+      }
+    } else if (this.spansDays(e)) {
+      lines.push(`时间：${this.fmtDateCn(e.startTime)} ${this.fmtTime(e.startTime)}`);
+      lines.push(`        ~ ${this.fmtDateCn(e.endTime)} ${this.fmtTime(e.endTime)}`);
+    } else {
+      lines.push(`时间：${this.fmtDateCn(e.startTime)} ${this.fmtTime(e.startTime)} ~ ${this.fmtTime(e.endTime)}`);
+    }
+    if (e.location !== '') {
+      lines.push(`地点：${e.location}`);
+    }
+    if (e.recurring) {
+      lines.push('重复：是');
+    }
+    if (e.calName !== '') {
+      lines.push(`日历本：${e.calName}${e.isSystem ? '' : '（只读）'}`);
+    }
+    if (e.description !== '') {
+      lines.push(`备注：${e.description}`);
+    }
+    this.getUIContext().showAlertDialog({
+      title: e.title === '' ? '(无标题)' : e.title,
+      message: lines.join('\n'),
+      autoCancel: true,
+      alignment: DialogAlignment.Center,
+      primaryButton: {
+        value: '关闭',
+        action: (): void => {}
+      }
+    });
+  }
+
   private addEvent(): void {
     AppStorage.setOrCreate<number>('pendingEventId', 0);
     AppStorage.setOrCreate<number>('pendingEventDate', this.selectedDate);
@@ -707,65 +769,109 @@ struct Index {
 
   @Builder
   monthBody() {
-    Column() {
-      // 星期表头
+    if (this.isLandscape) {
+      // 横屏（平板适配）：左右双栏——左侧月历，右侧当日日程
       Row() {
-        ForEach(WEEK_LABELS, (w: string) => {
-          Text(w)
-            .fontSize(12)
-            .fontColor($r('app.color.text_hint'))
-            .textAlign(TextAlign.Center)
-            .layoutWeight(1)
-        }, (w: string) => w)
+        Column() {
+          this.monthWeekHeader()
+          this.monthSwiper()
+        }
+        .layoutWeight(3)
+        .height('100%')
+
+        Divider()
+          .vertical(true)
+          .height('92%')
+          .strokeWidth(1)
+          .color($r('app.color.shadow_color'))
+
+        Column() {
+          this.dayPanelHeader()
+          this.eventList()
+        }
+        .layoutWeight(2)
+        .height('100%')
       }
       .width('100%')
-      .padding({ left: 12, right: 12 })
-
-      // 三页月格，左右滑动切换月份
-      Swiper(this.swiperController) {
-        ForEach(this.monthPages, (cells: MonthCell[]) => {
-          Column({ space: 2 }) {
-            ForEach(this.chunkCells(cells), (week: MonthCell[], idx: number) => {
-              Row({ space: 2 }) {
-                ForEach(week, (cell: MonthCell) => {
-                  this.dayCell(cell)
-                }, (cell: MonthCell) => `${cell.dateMs}_${cell.dateMs === this.selectedDate}`)
-              }
-              .width('100%')
-            }, (week: MonthCell[], idx: number) => String(idx))
-          }
-          .width('100%')
-        }, (cells: MonthCell[]) => String(cells[0].dateMs))
+      .layoutWeight(1)
+    } else {
+      // 竖屏：月历在上、当日日程在下（保持原布局）
+      Column() {
+        this.monthWeekHeader()
+        this.monthSwiper()
+        this.dayPanelHeader()
+        this.eventList()
       }
-      .index(1)
-      .loop(false)
-      .indicator(false)
       .width('100%')
-      .onChange((index: number) => {
-        this.handleSwiperChange(index);
-      })
+      .layoutWeight(1)
+    }
+  }
 
-      // 当日日程列表
-      Row({ space: 8 }) {
-        Text(this.fmtDateCn(this.selectedDate))
-          .fontSize(13)
-          .fontWeight(FontWeight.Medium)
-          .fontColor($r('app.color.text_secondary'))
-        Blank()
-        Text(this.fmtMonthTitle())
+  /** 月视图星期表头 */
+  @Builder
+  monthWeekHeader() {
+    Row() {
+      ForEach(WEEK_LABELS, (w: string) => {
+        Text(w)
           .fontSize(12)
           .fontColor($r('app.color.text_hint'))
-      }
-      .width('100%')
-      .padding({ left: 20, right: 20, top: 6 })
-      .gesture(LongPressGesture().onAction(() => {
-        this.showOccurrenceDebug(this.selectedDate);
-      }))
-
-      this.eventList()
+          .textAlign(TextAlign.Center)
+          .layoutWeight(1)
+      }, (w: string) => w)
     }
     .width('100%')
-    .layoutWeight(1)
+    .padding({ left: 12, right: 12 })
+  }
+
+  /** 月视图三页 Swiper（横屏时占满剩余高度并均分每周行，竖屏保持自然高度） */
+  @Builder
+  monthSwiper() {
+    Swiper(this.swiperController) {
+      ForEach(this.monthPages, (cells: MonthCell[]) => {
+        Column({ space: 2 }) {
+          ForEach(this.chunkCells(cells), (week: MonthCell[], idx: number) => {
+            Row({ space: 2 }) {
+              ForEach(week, (cell: MonthCell) => {
+                this.dayCell(cell)
+              }, (cell: MonthCell) => `${cell.dateMs}_${cell.dateMs === this.selectedDate}`)
+            }
+            .width('100%')
+            .layoutWeight(this.isLandscape ? 1 : 0)
+          }, (week: MonthCell[], idx: number) => String(idx))
+        }
+        .width('100%')
+        // 注意：不要给页面设百分比高度——竖屏时 Swiper 是自然高度，
+        // 子组件 height('100%') 对 auto 父容器解析为 0，整月网格会塌陷
+      }, (cells: MonthCell[]) => String(cells[0].dateMs))
+    }
+    .index(1)
+    .loop(false)
+    .indicator(false)
+    .width('100%')
+    .layoutWeight(this.isLandscape ? 1 : 0)
+    .onChange((index: number) => {
+      this.handleSwiperChange(index);
+    })
+  }
+
+  /** 当日日程标题行（长按可触发重复日程调试） */
+  @Builder
+  dayPanelHeader() {
+    Row({ space: 8 }) {
+      Text(this.fmtDateCn(this.selectedDate))
+        .fontSize(13)
+        .fontWeight(FontWeight.Medium)
+        .fontColor($r('app.color.text_secondary'))
+      Blank()
+      Text(this.fmtMonthTitle())
+        .fontSize(12)
+        .fontColor($r('app.color.text_hint'))
+    }
+    .width('100%')
+    .padding({ left: 20, right: 20, top: 6 })
+    .gesture(LongPressGesture().onAction(() => {
+      this.showOccurrenceDebug(this.selectedDate);
+    }))
   }
 
   /** 调试（临时）：长按月视图日期标题，检查重复日程在该日的首次发生情况 */
@@ -890,48 +996,144 @@ struct Index {
 
   @Builder
   weekBody() {
-    Column() {
-      Row({ space: 16 }) {
-        Blank()
-        Text('本周')
-          .fontSize(15)
-          .fontWeight(FontWeight.Bold)
-          .fontColor($r('app.color.text_primary'))
-          .onClick(() => {
-            this.goThisWeek();
+    if (this.isLandscape) {
+      // 横屏（平板适配）：左侧一周日期，右侧选中日日程
+      Row() {
+        Column() {
+          Text('本周')
+            .fontSize(15)
+            .fontWeight(FontWeight.Bold)
+            .fontColor($r('app.color.text_primary'))
+            .width('100%')
+            .textAlign(TextAlign.Center)
+            .padding({ top: 4, bottom: 8 })
+            .onClick(() => {
+              this.goThisWeek();
+            })
+          this.weekStripVertical()
+        }
+        .layoutWeight(1)
+        .height('100%')
+
+        Divider()
+          .vertical(true)
+          .height('92%')
+          .strokeWidth(1)
+          .color($r('app.color.shadow_color'))
+
+        Column() {
+          this.dayPanelHeader()
+          this.eventList()
+        }
+        .layoutWeight(2)
+        .height('100%')
+      }
+      .width('100%')
+      .layoutWeight(1)
+      .gesture(
+        SwipeGesture({ direction: SwipeDirection.Horizontal })
+          .onAction((event: GestureEvent) => {
+            if (Math.abs(event.angle) > 90) {
+              this.switchWeek(1);
+            } else {
+              this.switchWeek(-1);
+            }
           })
-        Blank()
+      )
+    } else {
+      // 竖屏：保持原上下结构
+      Column() {
+        Row({ space: 16 }) {
+          Blank()
+          Text('本周')
+            .fontSize(15)
+            .fontWeight(FontWeight.Bold)
+            .fontColor($r('app.color.text_primary'))
+            .onClick(() => {
+              this.goThisWeek();
+            })
+          Blank()
+        }
+        .width('100%')
+        .padding({ left: 20, right: 20, top: 4, bottom: 4 })
+
+        this.weekStrip()
+
+        Row({ space: 8 }) {
+          Text(this.fmtDateCn(this.selectedDate))
+            .fontSize(13)
+            .fontWeight(FontWeight.Medium)
+            .fontColor($r('app.color.text_secondary'))
+          Blank()
+        }
+        .width('100%')
+        .padding({ left: 20, right: 20, top: 8 })
+
+        this.eventList()
       }
       .width('100%')
-      .padding({ left: 20, right: 20, top: 4, bottom: 4 })
-
-      this.weekStrip()
-
-      Row({ space: 8 }) {
-        Text(this.fmtDateCn(this.selectedDate))
-          .fontSize(13)
-          .fontWeight(FontWeight.Medium)
-          .fontColor($r('app.color.text_secondary'))
-        Blank()
-      }
-      .width('100%')
-      .padding({ left: 20, right: 20, top: 8 })
-
-      this.eventList()
+      .layoutWeight(1)
+      .gesture(
+        SwipeGesture({ direction: SwipeDirection.Horizontal })
+          .onAction((event: GestureEvent) => {
+            // 左滑角度约 ±180（|angle|>90）→ 下一周；右滑约 0° → 上一周（与月视图 Swiper 方向一致）
+            if (Math.abs(event.angle) > 90) {
+              this.switchWeek(1);
+            } else {
+              this.switchWeek(-1);
+            }
+          })
+      )
     }
+  }
+
+  /** 周视图竖排日期条（横屏左栏：周一~周日从上到下，可上下滚动） */
+  @Builder
+  weekStripVertical() {
+    Scroll() {
+      Column({ space: 2 }) {
+        ForEach(this.weekStripDays(), (cell: MonthCell) => {
+          Row({ space: 10 }) {
+            Text(WEEK_LABELS[(new Date(cell.dateMs).getDay() + 6) % 7])
+              .fontSize(12)
+              .fontColor(cell.dateMs === this.selectedDate
+                ? $r('app.color.text_secondary') : $r('app.color.text_hint'))
+              .width(18)
+              .textAlign(TextAlign.Center)
+            Text(String(cell.day))
+              .fontSize(15)
+              .fontWeight(cell.dateMs === this.selectedDate || cell.isToday
+                ? FontWeight.Bold : FontWeight.Normal)
+              .fontColor(cell.dateMs === this.selectedDate
+                ? $r('app.color.button_text') : $r('app.color.text_primary'))
+              .width(32)
+              .height(32)
+              .textAlign(TextAlign.Center)
+              .borderRadius(16)
+              .backgroundColor(cell.dateMs === this.selectedDate
+                ? $r('app.color.selected_bg')
+                : (cell.isToday ? $r('app.color.today_bg') : Color.Transparent))
+          }
+          .width('100%')
+          .height(44)
+          .borderRadius(10)
+          .padding({ left: 10 })
+          .backgroundColor(cell.dateMs === this.selectedDate
+            ? $r('app.color.chip_off_bg') : Color.Transparent)
+          .onClick(() => {
+            this.selectedDate = cell.dateMs;
+          })
+        }, (cell: MonthCell) => `${cell.dateMs}_${cell.dateMs === this.selectedDate}`)
+      }
+      .width('100%')
+      .padding({ left: 8, right: 8, top: 2, bottom: 8 })
+      .constraintSize({ minHeight: '100%' })
+    }
+    .scrollBar(BarState.Off)
+    .edgeEffect(EdgeEffect.Spring)
+    .align(Alignment.Top)
     .width('100%')
     .layoutWeight(1)
-    .gesture(
-      SwipeGesture({ direction: SwipeDirection.Horizontal })
-        .onAction((event: GestureEvent) => {
-          // 左滑角度约 ±180（|angle|>90）→ 下一周；右滑约 0° → 上一周（与月视图 Swiper 方向一致）
-          if (Math.abs(event.angle) > 90) {
-            this.switchWeek(1);
-          } else {
-            this.switchWeek(-1);
-          }
-        })
-    )
   }
 
   /** 单日日程列表（周视图使用） */
@@ -952,7 +1154,7 @@ struct Index {
         }
       }
       .width('100%')
-      .padding({ left: 20, right: 20, top: 4, bottom: 90 })
+      .padding({ left: 20, right: 20, top: 4, bottom: 24 })
       .constraintSize({ minHeight: '100%' })
     }
     .layoutWeight(1)
@@ -1000,7 +1202,7 @@ struct Index {
     .layoutWeight(1)
     .scrollBar(BarState.Auto)
     .edgeEffect(EdgeEffect.Spring)
-    .padding({ left: 20, right: 20, top: 6, bottom: 90 })
+    .padding({ left: 20, right: 20, top: 6, bottom: 24 })
     .cachedCount(8)
   }
 
@@ -1097,7 +1299,7 @@ struct Index {
         }
       }
       .width('100%')
-      .padding({ left: 20, right: 20, top: 8, bottom: 90 })
+      .padding({ left: 20, right: 20, top: 8, bottom: 24 })
       .constraintSize({ minHeight: '100%' })
     }
     .layoutWeight(1)
@@ -1196,7 +1398,7 @@ struct Index {
           .borderRadius(6)
           .backgroundColor($r('app.color.chip_off_bg'))
       }
-      // 所属日历本：最右侧、垂直居中，颜色同日历本
+      // 所属日历本：最右侧、垂直居中，颜色同日历本；只读日历本加删除线标识
       if (e.calName !== '') {
         Text(e.calName)
           .fontSize(11)
@@ -1204,6 +1406,7 @@ struct Index {
           .maxLines(1)
           .textOverflow({ overflow: TextOverflow.Ellipsis })
           .constraintSize({ maxWidth: '30%' })
+          .decoration({ type: e.writable ? TextDecorationType.None : TextDecorationType.LineThrough })
       }
     }
     .alignItems(VerticalAlign.Center)
@@ -1221,23 +1424,26 @@ struct Index {
   dayCell(cell: MonthCell) {
     Column({ space: 2 }) {
       Text(String(cell.day))
-        .fontSize(13)
+        .fontSize(this.isLandscape ? 12 : 13)
         .fontWeight(cell.isToday || cell.dateMs === this.selectedDate ? FontWeight.Bold : FontWeight.Normal)
         .fontColor(!cell.inMonth
           ? $r('app.color.text_hint')
           : (cell.dateMs === this.selectedDate ? $r('app.color.button_text') : $r('app.color.text_primary')))
-        .width(26)
-        .height(26)
+        .width(this.isLandscape ? 22 : 26)
+        .height(this.isLandscape ? 22 : 26)
         .textAlign(TextAlign.Center)
-        .borderRadius(13)
+        .borderRadius(this.isLandscape ? 11 : 13)
         .backgroundColor(cell.dateMs === this.selectedDate
           ? $r('app.color.selected_bg')
           : (cell.isToday ? $r('app.color.today_bg') : Color.Transparent))
-      Text(cell.lunar)
-        .fontSize(8)
-        .fontColor(cell.dateMs === this.selectedDate
-          ? $r('app.color.text_secondary') : $r('app.color.text_hint'))
-        .maxLines(1)
+      if (!this.isLandscape) {
+        // 横屏高度有限，省略农历腾出空间
+        Text(cell.lunar)
+          .fontSize(8)
+          .fontColor(cell.dateMs === this.selectedDate
+            ? $r('app.color.text_secondary') : $r('app.color.text_hint'))
+          .maxLines(1)
+      }
     }
     .layoutWeight(1)
     .padding({ top: 4, bottom: 4 })

entry/src/main/ets/pages/SettingsPage.ets

@@ -1,19 +1,32 @@
 // entry/src/main/ets/pages/SettingsPage.ets
-// 设置页：系统日历混合显示开关 + 自动同步间隔
+// 设置页：系统日历模式（仅显示/备份到 CalDAV）+ 混合显示开关 + 自动同步间隔 + 后台同步
 import { router } from '@kit.ArkUI';
 import { common } from '@kit.AbilityKit';
 import { AppSettings } from '../common/AppSettings';
 import { BackgroundSyncService } from '../common/BackgroundSyncService';
+import { AccountStore, DavAccount } from '../common/AccountStore';
 import { LogUtil } from '../common/LogUtil';
 
 const INTERVAL_OPTIONS: number[] = [1, 5, 15, 30, 60];
 
+/** 日历本选项（备份目标 / 只读标记共用） */
+class BackupTarget {
+  calKey: string = '';
+  label: string = '';
+  serverWritable: boolean = true; // 服务器探测结果
+}
+
 @Entry
 @Component
 struct SettingsPage {
   @State showSystem: boolean = true;
   @State intervalMinutes: number = 1;
   @State backgroundSync: boolean = false;
+  @State sysMode: string = 'display'; // display | backup
+  @State backupKey: string = '';
+  @State backupTargets: BackupTarget[] = [];
+  @State allBooks: BackupTarget[] = []; // 全部 DAV 日历本（只读标记管理用）
+  @State manualKeys: string[] = [];     // 手动标记只读的 calKey
   private context?: common.Context;
 
   aboutToAppear(): void {
@@ -32,6 +45,128 @@ struct SettingsPage {
     AppSettings.getBackgroundSync(ctx).then((v: boolean): void => {
       this.backgroundSync = v;
     });
+    AppSettings.getSysCalMode(ctx).then((v: string): void => {
+      this.sysMode = v;
+    });
+    AppSettings.getManualReadonlyKeys(ctx).then((v: string[]): void => {
+      this.manualKeys = v;
+    });
+    this.loadBackupSettings();
+    this.loadAllBooks();
+  }
+
+  /** 加载全部 DAV 日历本（含探测到的写权限，只读标记管理用） */
+  private async loadAllBooks(): Promise<void> {
+    if (this.context === undefined) {
+      return;
+    }
+    const accounts: DavAccount[] = await AccountStore.loadAll(this.context);
+    const books: BackupTarget[] = [];
+    for (const acc of accounts) {
+      if (acc.type !== 'caldav') {
+        continue;
+      }
+      for (let i = 0; i < acc.calendarHrefs.length; i++) {
+        const b = new BackupTarget();
+        b.calKey = `${acc.id}_${i}`;
+        const bookName: string = i < acc.calendarNames.length ? acc.calendarNames[i] : `日历本 ${i + 1}`;
+        b.label = `${acc.name} · ${bookName}`;
+        b.serverWritable = acc.calendarWritable.length > i ? acc.calendarWritable[i] !== '0' : true;
+        books.push(b);
+      }
+    }
+    this.allBooks = books;
+  }
+
+  /** 手动标记/取消只读 */
+  private async toggleManualBook(b: BackupTarget): Promise<void> {
+    if (this.context === undefined) {
+      return;
+    }
+    const list: string[] = [...this.manualKeys];
+    const idx: number = list.indexOf(b.calKey);
+    if (idx >= 0) {
+      list.splice(idx, 1);
+    } else {
+      list.push(b.calKey);
+    }
+    this.manualKeys = list;
+    await AppSettings.setManualReadonlyKeys(this.context, list);
+    await this.loadBackupSettings(); // 备份目标候选同步排除
+    this.getUIContext().getPromptAction().showToast({
+      message: idx >= 0 ? '已恢复为可写，返回首页生效' : '已标记为只读，返回首页生效'
+    });
+  }
+
+  /** 日历本当前只读状态文案 */
+  private bookStateLabel(b: BackupTarget): string {
+    if (this.manualKeys.includes(b.calKey)) {
+      return '只读（手动）';
+    }
+    return b.serverWritable ? '可写' : '只读';
+  }
+
+  /** 加载备份目标候选（可写 DAV 日历本）+ 当前选择 */
+  private async loadBackupSettings(): Promise<void> {
+    if (this.context === undefined) {
+      return;
+    }
+    const accounts: DavAccount[] = await AccountStore.loadAll(this.context);
+    const targets: BackupTarget[] = [];
+    for (const acc of accounts) {
+      if (acc.type !== 'caldav') {
+        continue;
+      }
+      for (let i = 0; i < acc.calendarHrefs.length; i++) {
+        const writable: boolean = acc.calendarWritable.length > i
+          ? acc.calendarWritable[i] !== '0' : true;
+        if (!writable) {
+          continue;
+        }
+        const t = new BackupTarget();
+        t.calKey = `${acc.id}_${i}`;
+        const bookName: string = i < acc.calendarNames.length ? acc.calendarNames[i] : `日历本 ${i + 1}`;
+        t.label = `${acc.name} · ${bookName}`;
+        t.serverWritable = writable;
+        targets.push(t);
+      }
+    }
+    // 手动标记只读的本不可作为备份目标
+    const manual: string[] = await AppSettings.getManualReadonlyKeys(this.context);
+    this.backupTargets = targets.filter((t: BackupTarget): boolean => !manual.includes(t.calKey));
+    this.backupTargets = targets;
+    const saved: string = await AppSettings.getBackupCalKey(this.context);
+    this.backupKey = targets.some((t: BackupTarget): boolean => t.calKey === saved) ? saved : '';
+  }
+
+  private async saveSysMode(mode: string): Promise<void> {
+    if (this.context === undefined) {
+      return;
+    }
+    this.sysMode = mode;
+    await AppSettings.setSysCalMode(this.context, mode);
+    if (mode === 'backup' && this.backupKey === '') {
+      // 自动选中第一个可写日历本
+      if (this.backupTargets.length > 0) {
+        this.backupKey = this.backupTargets[0].calKey;
+        await AppSettings.setBackupCalKey(this.context, this.backupKey);
+      }
+    }
+    this.getUIContext().getPromptAction().showToast({
+      message: mode === 'backup'
+        ? '已开启备份：下次同步时把系统本地日程导入所选日历本'
+        : '已切换为仅显示：不再把系统日程备份到 CalDAV'
+    });
+  }
+
+  private async saveBackupTarget(calKey: string): Promise<void> {
+    if (this.context === undefined) {
+      return;
+    }
+    this.backupKey = calKey;
+    await AppSettings.setBackupCalKey(this.context, calKey);
+    this.getUIContext().getPromptAction()
+      .showToast({ message: '备份目标已更新，下次同步生效' });
   }
 
   private async saveShowSystem(value: boolean): Promise<void> {
@@ -96,7 +231,125 @@ struct SettingsPage {
 
       Scroll() {
         Column({ space: 12 }) {
-          // 系统日历混合显示
+          // 系统日历模式：仅显示 / 备份到 CalDAV
+          Column({ space: 8 }) {
+            Row({ space: 10 }) {
+              Column({ space: 2 }) {
+                Text('系统日历')
+                  .fontSize(15)
+                  .fontWeight(FontWeight.Medium)
+                  .fontColor($r('app.color.text_primary'))
+                Text('选择手机系统日历日程的处理方式')
+                  .fontSize(12)
+                  .fontColor($r('app.color.text_secondary'))
+              }
+              .alignItems(HorizontalAlign.Start)
+              .layoutWeight(1)
+            }
+            .width('100%')
+            Select([{ value: '仅显示（不做备份）' }, { value: '备份到 CalDAV 日历本' }] as SelectOption[])
+              .selected(this.sysMode === 'backup' ? 1 : 0)
+              .value(this.sysMode === 'backup' ? '备份到 CalDAV 日历本' : '仅显示（不做备份）')
+              .fontColor($r('app.color.text_primary'))
+              .font({ size: 14 })
+              .optionFont({ size: 14 })
+              .selectedOptionFont({ size: 14 })
+              .width('100%')
+              .onSelect((index: number) => {
+                const mode: string = index === 1 ? 'backup' : 'display';
+                if (mode !== this.sysMode) {
+                  this.saveSysMode(mode);
+                }
+              })
+            if (this.sysMode === 'backup') {
+              Text(this.backupTargets.length > 0
+                ? '备份目标（可写日历本）：导入后随同步上传服务器，换机/丢失也有备份'
+                : '没有可写的 CalDAV 日历本，请先添加账号或检查日历本权限')
+                .fontSize(12)
+                .fontColor(this.backupTargets.length > 0
+                  ? $r('app.color.text_secondary') : $r('app.color.error'))
+                .width('100%')
+              if (this.backupTargets.length > 0) {
+                Select(this.backupTargets.map((t: BackupTarget): SelectOption => {
+                  return { value: t.label } as SelectOption;
+                }) as SelectOption[])
+                  .selected(this.backupTargets.findIndex((t: BackupTarget): boolean => t.calKey === this.backupKey))
+                  .value(this.backupTargets.find((t: BackupTarget): boolean => t.calKey === this.backupKey)?.label
+                    ?? '请选择日历本')
+                  .fontColor($r('app.color.text_primary'))
+                  .font({ size: 14 })
+                  .optionFont({ size: 14 })
+                  .selectedOptionFont({ size: 14 })
+                  .width('100%')
+                  .onSelect((index: number) => {
+                    if (index >= 0 && index < this.backupTargets.length) {
+                      this.saveBackupTarget(this.backupTargets[index].calKey);
+                    }
+                  })
+              }
+            }
+          }
+          .alignItems(HorizontalAlign.Start)
+          .width('100%')
+          .padding(14)
+          .borderRadius(12)
+          .backgroundColor($r('app.color.card_bg'))
+          .border({ width: 1, color: $r('app.color.shadow_color') })
+
+          // 日历本只读标记（部分服务器不在 CalDAV 层拒绝写入，自动探测无法区分时手动标记）
+          Column({ space: 8 }) {
+            Row({ space: 10 }) {
+              Column({ space: 2 }) {
+                Text('日历本只读标记')
+                  .fontSize(15)
+                  .fontWeight(FontWeight.Medium)
+                  .fontColor($r('app.color.text_primary'))
+                Text('点击日历本切换只读标记：标记后其中日程仅可查看详情，新建日程时不再显示')
+                  .fontSize(12)
+                  .fontColor($r('app.color.text_secondary'))
+              }
+              .alignItems(HorizontalAlign.Start)
+              .layoutWeight(1)
+            }
+            .width('100%')
+            if (this.allBooks.length === 0) {
+              Text('暂无 CalDAV 日历本')
+                .fontSize(12)
+                .fontColor($r('app.color.text_hint'))
+                .width('100%')
+            }
+            ForEach(this.allBooks, (b: BackupTarget) => {
+              Row({ space: 8 }) {
+                Text(b.label)
+                  .fontSize(13)
+                  .fontColor($r('app.color.text_primary'))
+                  .maxLines(1)
+                  .textOverflow({ overflow: TextOverflow.Ellipsis })
+                  .layoutWeight(1)
+                Text(this.bookStateLabel(b))
+                  .fontSize(11)
+                  .fontColor(this.bookStateLabel(b) === '可写'
+                    ? $r('app.color.success') : $r('app.color.error'))
+                  .padding({ left: 8, right: 8, top: 3, bottom: 3 })
+                  .borderRadius(10)
+                  .backgroundColor(this.bookStateLabel(b) === '可写'
+                    ? $r('app.color.success_bg') : $r('app.color.error_bg'))
+              }
+              .width('100%')
+              .padding({ top: 6, bottom: 6 })
+              .onClick(() => {
+                this.toggleManualBook(b);
+              })
+            }, (b: BackupTarget) => `${b.calKey}_${this.manualKeys.includes(b.calKey) ? 1 : 0}`)
+          }
+          .alignItems(HorizontalAlign.Start)
+          .width('100%')
+          .padding(14)
+          .borderRadius(12)
+          .backgroundColor($r('app.color.card_bg'))
+          .border({ width: 1, color: $r('app.color.shadow_color') })
+
+          // 混合显示系统日历
           Row({ space: 10 }) {
             Column({ space: 2 }) {
               Text('混合显示系统日历')

entry/src/main/ets/syncwork/SyncWorkAbility.ets

@@ -7,6 +7,7 @@ import { DavAccount, AccountStore, TYPE_CALDAV } from '../common/AccountStore';
 import { SyncEngine } from '../common/SyncEngine';
 import { CardDataService } from '../common/CardDataService';
 import { ReminderService } from '../common/ReminderService';
+import { SystemCalendarImport } from '../common/SystemCalendarImport';
 import { LogUtil } from '../common/LogUtil';
 
 export default class SyncWorkAbility extends WorkSchedulerExtensionAbility {
@@ -24,6 +25,12 @@ export default class SyncWorkAbility extends WorkSchedulerExtensionAbility {
     try {
       const context = this.context;
       const accounts: DavAccount[] = await AccountStore.loadAll(context);
+      // 备份模式：先导入系统本地日历（幂等），再随同步推送
+      try {
+        await SystemCalendarImport.importIfNeeded(context);
+      } catch (err) {
+        // 导入失败不影响正常同步
+      }
       let ok: number = 0;
       for (const acc of accounts) {
         if (acc.type !== TYPE_CALDAV) {

entry/src/main/module.json5

@@ -5,7 +5,8 @@
     "description": "$string:module_desc",
     "mainElement": "EntryAbility",
     "deviceTypes": [
-      "phone"
+      "phone",
+      "tablet"
     ],
     "requestPermissions": [
       {
@@ -58,6 +59,7 @@
         "startWindowIcon": "$media:startIcon",
         "startWindowBackground": "$color:start_window_background",
         "exported": true,
+        "orientation": "auto_rotation_restricted",
         "backgroundModes": [
           "dataTransfer"
         ],