mobile nav implemented

dark mode need rifinements

frontend/src/lib/theme.ts

@@ -0,0 +1,79 @@
+/**
+ * Theme utilities for dark/light mode
+ */
+
+export type Theme = 'light' | 'dark';
+
+/**
+ * Get the current theme from localStorage or system preference
+ */
+export function getInitialTheme(): Theme {
+  // Check localStorage first
+  const savedTheme = localStorage.getItem('theme') as Theme;
+  if (savedTheme) {
+    return savedTheme;
+  }
+  
+  // Check system preference
+  if (window.matchMedia('(prefers-color-scheme: dark)').matches) {
+    return 'dark';
+  }
+  
+  // Default to light
+  return 'light';
+}
+
+/**
+ * Apply theme to document
+ */
+export function applyTheme(theme: Theme): void {
+  const root = document.documentElement;
+  
+  if (theme === 'dark') {
+    root.classList.add('dark');
+  } else {
+    root.classList.remove('dark');
+  }
+  
+  // Save to localStorage
+  localStorage.setItem('theme', theme);
+}
+
+/**
+ * Initialize theme on page load
+ */
+export function initializeTheme(): void {
+  const theme = getInitialTheme();
+  applyTheme(theme);
+}
+
+/**
+ * Toggle between light and dark themes
+ */
+export function toggleTheme(): Theme {
+  const currentTheme = getInitialTheme();
+  const newTheme = currentTheme === 'light' ? 'dark' : 'light';
+  applyTheme(newTheme);
+  return newTheme;
+}
+
+/**
+ * Listen for system theme changes
+ */
+export function watchSystemTheme(callback: (theme: Theme) => void): () => void {
+  const mediaQuery = window.matchMedia('(prefers-color-scheme: dark)');
+  
+  const handleChange = (e: MediaQueryListEvent) => {
+    // Only update if user hasn't set a preference in localStorage
+    if (!localStorage.getItem('theme')) {
+      const theme = e.matches ? 'dark' : 'light';
+      callback(theme);
+      applyTheme(theme);
+    }
+  };
+  
+  mediaQuery.addEventListener('change', handleChange);
+  
+  // Return cleanup function
+  return () => mediaQuery.removeEventListener('change', handleChange);
+}