feat: add dark mode, fuzzy search, favorites, and URL sharing

Implemented Phases 5-7 of the implementation plan with major UX enhancements:

**Dark Mode (Phase 9)**
- Added ThemeToggle component with localStorage persistence
- System preference detection
- Smooth theme transitions
- Moon/Sun icon toggle in header

**Fuzzy Search with Fuse.js (Phase 5)**
- Integrated Fuse.js for intelligent font search
- 30% threshold for flexible matching
- Search by font name and filename
- Clear button for search input
- Much better than simple string matching

**Favorites & Recent Fonts System (Phase 7)**
- localStorage-based favorites with heart icon toggle
- Auto-tracking of recently used fonts (max 10)
- Filter tabs: All / Favorites / Recent
- Favorite hearts visible on hover
- Red filled heart for favorited fonts
- Stats showing favorite and recent counts

**Shareable URLs (Phase 6)**
- Encode text + font in URL parameters
- Auto-load from URL on page load
- Share button copies URL to clipboard
- Clean URL updates without page reload
- Perfect for sharing ASCII art creations

**Enhanced Font Selector**
- 3-tab filter system (All/Favorites/Recent)
- Visual feedback for selected fonts
- Empty states for each filter
- Font count statistics
- Heart icon for quick favoriting
- Recent fonts sorted by usage order

**UX Improvements**
- Copy feedback ("Copied to clipboard! ✓")
- Share feedback ("URL copied to clipboard! ✓")
- Responsive button layout
- Better empty states
- Improved accessibility with aria-labels

**Tech Highlights**
- Client-side localStorage management
- URL encoding/decoding utilities
- React hooks for state management
- Fuse.js fuzzy search integration
- Theme persistence across sessions

The app now has professional-grade features rivaling any modern web app!

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

components/converter/FigletConverter.tsx

@@ -7,6 +7,8 @@ import { FontSelector } from './FontSelector';
 import { textToAscii } from '@/lib/figlet/figletService';
 import { getFontList } from '@/lib/figlet/fontLoader';
 import { debounce } from '@/lib/utils/debounce';
+import { addRecentFont } from '@/lib/storage/favorites';
+import { decodeFromUrl, updateUrl, getShareableUrl } from '@/lib/utils/urlSharing';
 import type { FigletFont } from '@/types/figlet';
 
 export function FigletConverter() {
@@ -16,10 +18,18 @@ export function FigletConverter() {
   const [fonts, setFonts] = React.useState<FigletFont[]>([]);
   const [isLoading, setIsLoading] = React.useState(false);
   const [isCopied, setIsCopied] = React.useState(false);
+  const [isShared, setIsShared] = React.useState(false);
 
-  // Load fonts on mount
+  // Load fonts and check URL params on mount
   React.useEffect(() => {
     getFontList().then(setFonts);
+
+    // Check for URL parameters
+    const urlState = decodeFromUrl();
+    if (urlState) {
+      if (urlState.text) setText(urlState.text);
+      if (urlState.font) setSelectedFont(urlState.font);
+    }
   }, []);
 
   // Generate ASCII art
@@ -48,6 +58,12 @@ export function FigletConverter() {
   // Trigger generation when text or font changes
   React.useEffect(() => {
     generateAsciiArt(text, selectedFont);
+    // Track recent fonts
+    if (selectedFont) {
+      addRecentFont(selectedFont);
+    }
+    // Update URL
+    updateUrl(text, selectedFont);
   }, [text, selectedFont, generateAsciiArt]);
 
   // Copy to clipboard
@@ -78,6 +94,19 @@ export function FigletConverter() {
     URL.revokeObjectURL(url);
   };
 
+  // Share (copy URL to clipboard)
+  const handleShare = async () => {
+    const shareUrl = getShareableUrl(text, selectedFont);
+
+    try {
+      await navigator.clipboard.writeText(shareUrl);
+      setIsShared(true);
+      setTimeout(() => setIsShared(false), 2000);
+    } catch (error) {
+      console.error('Failed to copy URL:', error);
+    }
+  };
+
   return (
     <div className="grid grid-cols-1 lg:grid-cols-3 gap-6">
       {/* Left Column - Input and Preview */}
@@ -89,10 +118,11 @@ export function FigletConverter() {
         />
 
         <FontPreview
-          text={isCopied ? 'Copied to clipboard! ✓' : asciiArt}
+          text={isCopied ? 'Copied to clipboard! ✓' : isShared ? 'URL copied to clipboard! ✓' : asciiArt}
           isLoading={isLoading}
           onCopy={handleCopy}
           onDownload={handleDownload}
+          onShare={handleShare}
         />
       </div>
 

components/converter/FontPreview.tsx

@@ -3,7 +3,7 @@
 import * as React from 'react';
 import { Card } from '@/components/ui/Card';
 import { Button } from '@/components/ui/Button';
-import { Copy, Download } from 'lucide-react';
+import { Copy, Download, Share2 } from 'lucide-react';
 import { cn } from '@/lib/utils/cn';
 
 export interface FontPreviewProps {
@@ -11,10 +11,11 @@ export interface FontPreviewProps {
   isLoading?: boolean;
   onCopy?: () => void;
   onDownload?: () => void;
+  onShare?: () => void;
   className?: string;
 }
 
-export function FontPreview({ text, isLoading, onCopy, onDownload, className }: FontPreviewProps) {
+export function FontPreview({ text, isLoading, onCopy, onDownload, onShare, className }: FontPreviewProps) {
   return (
     <Card className={cn('relative', className)}>
       <div className="p-6">
@@ -27,6 +28,12 @@ export function FontPreview({ text, isLoading, onCopy, onDownload, className }:
                 Copy
               </Button>
             )}
+            {onShare && (
+              <Button variant="outline" size="sm" onClick={onShare} title="Copy shareable URL">
+                <Share2 className="h-4 w-4" />
+                Share
+              </Button>
+            )}
             {onDownload && (
               <Button variant="outline" size="sm" onClick={onDownload}>
                 <Download className="h-4 w-4" />

components/converter/FontSelector.tsx

@@ -1,11 +1,13 @@
 'use client';
 
 import * as React from 'react';
+import Fuse from 'fuse.js';
 import { Input } from '@/components/ui/Input';
 import { Card } from '@/components/ui/Card';
-import { Search } from 'lucide-react';
+import { Search, X, Heart, Clock, List } from 'lucide-react';
 import { cn } from '@/lib/utils/cn';
 import type { FigletFont } from '@/types/figlet';
+import { getFavorites, getRecentFonts, toggleFavorite, isFavorite } from '@/lib/storage/favorites';
 
 export interface FontSelectorProps {
   fonts: FigletFont[];
@@ -14,58 +16,174 @@ export interface FontSelectorProps {
   className?: string;
 }
 
+type FilterType = 'all' | 'favorites' | 'recent';
+
 export function FontSelector({ fonts, selectedFont, onSelectFont, className }: FontSelectorProps) {
   const [searchQuery, setSearchQuery] = React.useState('');
+  const [filter, setFilter] = React.useState<FilterType>('all');
+  const [favorites, setFavorites] = React.useState<string[]>([]);
+  const [recentFonts, setRecentFonts] = React.useState<string[]>([]);
+
+  // Load favorites and recent fonts
+  React.useEffect(() => {
+    setFavorites(getFavorites());
+    setRecentFonts(getRecentFonts());
+  }, []);
+
+  // Initialize Fuse.js for fuzzy search
+  const fuse = React.useMemo(() => {
+    return new Fuse(fonts, {
+      keys: ['name', 'fileName'],
+      threshold: 0.3,
+      includeScore: true,
+    });
+  }, [fonts]);
 
   const filteredFonts = React.useMemo(() => {
-    if (!searchQuery) return fonts;
+    let fontsToFilter = fonts;
 
-    const query = searchQuery.toLowerCase();
-    return fonts.filter(font =>
-      font.name.toLowerCase().includes(query)
-    );
-  }, [fonts, searchQuery]);
+    // Apply category filter
+    if (filter === 'favorites') {
+      fontsToFilter = fonts.filter(f => favorites.includes(f.name));
+    } else if (filter === 'recent') {
+      fontsToFilter = fonts.filter(f => recentFonts.includes(f.name));
+      // Sort by recent order
+      fontsToFilter.sort((a, b) => {
+        return recentFonts.indexOf(a.name) - recentFonts.indexOf(b.name);
+      });
+    }
+
+    // Apply search query
+    if (!searchQuery) return fontsToFilter;
+
+    const results = fuse.search(searchQuery);
+    const searchResults = results.map(result => result.item);
+
+    // Filter search results by category
+    if (filter === 'favorites') {
+      return searchResults.filter(f => favorites.includes(f.name));
+    } else if (filter === 'recent') {
+      return searchResults.filter(f => recentFonts.includes(f.name));
+    }
+
+    return searchResults;
+  }, [fonts, searchQuery, fuse, filter, favorites, recentFonts]);
+
+  const handleToggleFavorite = (fontName: string, e: React.MouseEvent) => {
+    e.stopPropagation();
+    toggleFavorite(fontName);
+    setFavorites(getFavorites());
+  };
 
   return (
     <Card className={className}>
       <div className="p-6">
         <h3 className="text-sm font-medium mb-4">Select Font</h3>
 
-        <div className="relative mb-4">
-          <Search className="absolute left-3 top-1/2 -translate-y-1/2 h-4 w-4 text-muted-foreground" />
-          <Input
-            type="text"
-            placeholder="Search fonts..."
-            value={searchQuery}
-            onChange={(e) => setSearchQuery(e.target.value)}
-            className="pl-9"
-          />
+        {/* Filter Tabs */}
+        <div className="flex gap-1 mb-4 p-1 bg-muted rounded-lg">
+          <button
+            onClick={() => setFilter('all')}
+            className={cn(
+              'flex-1 px-3 py-1.5 text-xs font-medium rounded-md transition-colors',
+              filter === 'all' ? 'bg-background shadow-sm' : 'hover:bg-background/50'
+            )}
+          >
+            <List className="inline-block h-3 w-3 mr-1" />
+            All
+          </button>
+          <button
+            onClick={() => setFilter('favorites')}
+            className={cn(
+              'flex-1 px-3 py-1.5 text-xs font-medium rounded-md transition-colors',
+              filter === 'favorites' ? 'bg-background shadow-sm' : 'hover:bg-background/50'
+            )}
+          >
+            <Heart className="inline-block h-3 w-3 mr-1" />
+            Favorites
+          </button>
+          <button
+            onClick={() => setFilter('recent')}
+            className={cn(
+              'flex-1 px-3 py-1.5 text-xs font-medium rounded-md transition-colors',
+              filter === 'recent' ? 'bg-background shadow-sm' : 'hover:bg-background/50'
+            )}
+          >
+            <Clock className="inline-block h-3 w-3 mr-1" />
+            Recent
+          </button>
         </div>
 
+        {/* Search Input */}
+        <div className="relative mb-4">
+          <Search className="absolute left-3 top-1/2 -translate-y-1/2 h-4 w-4 text-muted-foreground pointer-events-none" />
+          <Input
+            type="text"
+            placeholder="Search fonts... (fuzzy)"
+            value={searchQuery}
+            onChange={(e) => setSearchQuery(e.target.value)}
+            className="pl-9 pr-9"
+          />
+          {searchQuery && (
+            <button
+              onClick={() => setSearchQuery('')}
+              className="absolute right-3 top-1/2 -translate-y-1/2 text-muted-foreground hover:text-foreground"
+              aria-label="Clear search"
+            >
+              <X className="h-4 w-4" />
+            </button>
+          )}
+        </div>
+
+        {/* Font List */}
         <div className="max-h-[400px] overflow-y-auto space-y-1 pr-2">
           {filteredFonts.length === 0 ? (
             <div className="text-sm text-muted-foreground text-center py-8">
-              No fonts found
+              {filter === 'favorites' && 'No favorite fonts yet'}
+              {filter === 'recent' && 'No recent fonts'}
+              {filter === 'all' && 'No fonts found'}
             </div>
           ) : (
             filteredFonts.map((font) => (
-              <button
+              <div
                 key={font.name}
-                onClick={() => onSelectFont(font.name)}
                 className={cn(
-                  'w-full text-left px-3 py-2 rounded-md text-sm transition-colors',
+                  'group flex items-center gap-2 px-3 py-2 rounded-md text-sm transition-colors',
                   'hover:bg-accent hover:text-accent-foreground',
                   selectedFont === font.name && 'bg-accent text-accent-foreground font-medium'
                 )}
               >
-                {font.name}
-              </button>
+                <button
+                  onClick={() => onSelectFont(font.name)}
+                  className="flex-1 text-left"
+                >
+                  {font.name}
+                </button>
+                <button
+                  onClick={(e) => handleToggleFavorite(font.name, e)}
+                  className={cn(
+                    'opacity-0 group-hover:opacity-100 transition-opacity',
+                    isFavorite(font.name) && 'opacity-100'
+                  )}
+                  aria-label={isFavorite(font.name) ? 'Remove from favorites' : 'Add to favorites'}
+                >
+                  <Heart
+                    className={cn(
+                      'h-4 w-4 transition-colors',
+                      isFavorite(font.name) ? 'fill-red-500 text-red-500' : 'text-muted-foreground hover:text-red-500'
+                    )}
+                  />
+                </button>
+              </div>
             ))
           )}
         </div>
 
+        {/* Stats */}
         <div className="mt-4 pt-4 border-t text-xs text-muted-foreground">
-          {filteredFonts.length} font{filteredFonts.length !== 1 ? 's' : ''} available
+          {filteredFonts.length} font{filteredFonts.length !== 1 ? 's' : ''}
+          {filter === 'favorites' && ` • ${favorites.length} total favorites`}
+          {filter === 'recent' && ` • ${recentFonts.length} recent`}
         </div>
       </div>
     </Card>

components/layout/ThemeToggle.tsx

@@ -0,0 +1,42 @@
+'use client';
+
+import * as React from 'react';
+import { Moon, Sun } from 'lucide-react';
+import { Button } from '@/components/ui/Button';
+
+export function ThemeToggle() {
+  const [theme, setTheme] = React.useState<'light' | 'dark'>('light');
+
+  React.useEffect(() => {
+    // Check for saved theme preference or default to light
+    const savedTheme = localStorage.getItem('theme') as 'light' | 'dark' | null;
+    const prefersDark = window.matchMedia('(prefers-color-scheme: dark)').matches;
+    const initialTheme = savedTheme || (prefersDark ? 'dark' : 'light');
+
+    setTheme(initialTheme);
+    document.documentElement.classList.toggle('dark', initialTheme === 'dark');
+  }, []);
+
+  const toggleTheme = () => {
+    const newTheme = theme === 'light' ? 'dark' : 'light';
+    setTheme(newTheme);
+    localStorage.setItem('theme', newTheme);
+    document.documentElement.classList.toggle('dark', newTheme === 'dark');
+  };
+
+  return (
+    <Button
+      variant="outline"
+      size="icon"
+      onClick={toggleTheme}
+      aria-label="Toggle theme"
+      title={`Switch to ${theme === 'light' ? 'dark' : 'light'} mode`}
+    >
+      {theme === 'light' ? (
+        <Moon className="h-4 w-4" />
+      ) : (
+        <Sun className="h-4 w-4" />
+      )}
+    </Button>
+  );
+}