center nav links and calendar two-panel layout on wide screens

src/ui/app.ts

@@ -118,7 +118,7 @@ export class App {
     this.container.innerHTML = `
       <div class="app-container min-h-screen flex flex-col">
         <header class="bg-navy text-parchment p-3 flex items-center shadow-md">
-          <nav class="flex flex-wrap gap-4 text-sm ml-auto">
+          <nav class="flex flex-wrap gap-4 text-sm mx-auto">
             <a href="#calendar" class="nav-link hover:text-gold transition-colors" data-view="calendar">${t.nav.calendar}</a>
             <details class="nav-group relative" data-nav="library">
               <summary class="cursor-pointer list-none hover:text-gold transition-colors flex items-center gap-1">${t.nav.library} <span class="text-xs">▾</span></summary>

src/ui/calendar-view.ts

@@ -556,7 +556,7 @@ export class CalendarView {
     const julianStr = `${julianDayName}, ${this.currentDate.getDay()} ${this.t.calendar.monthsGenitive[this.currentDate.getMonth() - 1]}, год ${julianYear} ${this.t.calendar.fromYear}, ${annoMundi} ${this.t.calendar.fromAdam}`;
 
     this.container.innerHTML = `
-      <div class="flex flex-col lg:flex-row h-full">
+      <div class="flex flex-col lg:flex-row h-full justify-center">
         <div class="lg:w-80 bg-parchment-dark border-r border-gold/20 p-4 flex-shrink-0">
           <div class="flex items-center justify-between mb-4">
             <button id="prev-month" class="p-2 hover:bg-navy/10 rounded">◀</button>