Add tablet landscape layout and allow PWA horizontal orientation.

Split mobile and tablet breakpoints, restore desktop-style reading on landscape tablets, and lock Android tablet apps to landscape.

Co-authored-by: Cursor <cursoragent@cursor.com>

.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;