diff --git a/.vitepress/pwa.mts b/.vitepress/pwa.mts
index 5997086..b0d864e 100644
--- a/.vitepress/pwa.mts
+++ b/.vitepress/pwa.mts
@@ -22,7 +22,7 @@ export function createPwaPlugin() {
       theme_color: '#0f3460',
       background_color: '#1a1a2e',
       display: 'standalone',
-      orientation: 'portrait-primary',
+      orientation: 'any',
       scope: '/',
       start_url: '/',
       categories: ['books', 'education'],
diff --git a/.vitepress/theme/InstallApp.vue b/.vitepress/theme/InstallApp.vue
index d208f51..fa06f8a 100644
--- a/.vitepress/theme/InstallApp.vue
+++ b/.vitepress/theme/InstallApp.vue
@@ -36,7 +36,7 @@ function onBeforeInstallPrompt(event: Event) {
 }
 
 onMounted(() => {
-  isMobile.value = window.matchMedia('(max-width: 768px)').matches
+  isMobile.value = window.matchMedia('(max-width: 767px)').matches
 
   if (sessionStorage.getItem('install-app-dismissed') === '1') {
     dismissed.value = true
@@ -172,7 +172,7 @@ function dismiss() {
   color: var(--vp-c-text-2);
 }
 
-@media (max-width: 768px) {
+@media (max-width: 767px) {
   .install-app {
     left: 12px;
     right: 12px;
diff --git a/.vitepress/theme/custom.css b/.vitepress/theme/custom.css
index 8330f40..57396cf 100644
--- a/.vitepress/theme/custom.css
+++ b/.vitepress/theme/custom.css
@@ -110,7 +110,7 @@ html {
   line-height: 1.45;
 }
 
-@media (max-width: 960px) {
+@media (max-width: 767px) {
   .VPContent {
     padding-top: 0;
   }
@@ -174,6 +174,57 @@ html {
   }
 }
 
+/* 平板竖屏：介于手机与桌面之间 */
+@media (min-width: 768px) and (max-width: 1024px) and (orientation: portrait) {
+  .VPDoc .container {
+    padding: 0 24px;
+  }
+
+  .vp-doc {
+    font-size: 17px;
+    padding: 12px 0 64px;
+  }
+
+  .VPDocFooter .pager-link {
+    min-height: 44px;
+  }
+}
+
+/* 平板横屏：恢复桌面式双栏阅读 */
+@media (min-width: 768px) and (orientation: landscape) {
+  .VPDoc .aside,
+  .VPDoc .aside-container {
+    display: block !important;
+  }
+
+  .VPDoc.has-aside .content-container {
+    max-width: 688px;
+  }
+
+  .VPDoc .container {
+    padding: 0 24px;
+  }
+
+  .vp-doc {
+    font-size: 16px;
+    line-height: 1.85;
+    padding: 16px 0 48px;
+  }
+
+  .VPDocFooter .pager-link {
+    min-height: 44px;
+  }
+
+  .VPDocFooter .prev-next {
+    display: flex;
+    gap: 16px;
+  }
+
+  .VPDocFooter .pager-link {
+    flex: 1;
+  }
+}
+
 @media (max-width: 640px) {
   .VPNavBarTitle .title {
     font-size: 15px;
diff --git a/.vitepress/theme/index.ts b/.vitepress/theme/index.ts
index eda76b3..752be4d 100644
--- a/.vitepress/theme/index.ts
+++ b/.vitepress/theme/index.ts
@@ -1,12 +1,14 @@
 import DefaultTheme from 'vitepress/theme'
 import { h, defineComponent } from 'vue'
 import InstallApp from './InstallApp.vue'
+import { initTabletLandscape } from './tablet-landscape'
 import './custom.css'
 
 if (typeof window !== 'undefined') {
   import('virtual:pwa-register').then(({ registerSW }) => {
     registerSW({ immediate: true })
   })
+  initTabletLandscape()
 }
 
 /** 旧 markdown 的 <font> 标签改为 div，避免手机端布局溢出 */
diff --git a/.vitepress/theme/tablet-landscape.ts b/.vitepress/theme/tablet-landscape.ts
new file mode 100644
index 0000000..06d3da2
--- /dev/null
+++ b/.vitepress/theme/tablet-landscape.ts
@@ -0,0 +1,25 @@
+/** Android 平板 PWA 安装后默认锁定横屏 */
+export function initTabletLandscape() {
+  if (typeof window === 'undefined') return
+
+  function tryLockLandscape() {
+    const isStandalone =
+      window.matchMedia('(display-mode: standalone)').matches ||
+      (window.navigator as Navigator & { standalone?: boolean }).standalone
+
+    if (!isStandalone || !/Android/i.test(navigator.userAgent)) return
+
+    const shortestSide = Math.min(window.screen.width, window.screen.height)
+    if (shortestSide < 600) return
+
+    const lock = screen.orientation?.lock?.bind(screen.orientation)
+    if (!lock) return
+
+    lock('landscape-primary').catch(() => {
+      lock('landscape').catch(() => {})
+    })
+  }
+
+  tryLockLandscape()
+  window.addEventListener('orientationchange', tryLockLandscape)
+}