Redesign stats page with dark theme and enhanced statistics

- Implement dark gradient background with glassmorphism cards
- Add new statistics: worst day, best book, most seen book, unique books by testament
- Design mobile-first responsive grid layout with optimized spacing
- Update Container component to support dark theme (bg-white/10, border-white/20)
- Calculate book-specific stats by linking completions to daily verses
- Improve visual hierarchy with icons and color-coded stat cards

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

src/routes/stats/+page.server.ts

@@ -1,7 +1,8 @@
 import { db } from '$lib/server/db';
-import { dailyCompletions, type DailyCompletion } from '$lib/server/db/schema';
+import { dailyCompletions, dailyVerses, type DailyCompletion } from '$lib/server/db/schema';
 import { eq, desc } from 'drizzle-orm';
 import type { PageServerLoad } from './$types';
+import { bibleBooks } from '$lib/types/bible';
 
 export const load: PageServerLoad = async ({ url, locals }) => {
 	// Check if user is authenticated
@@ -51,7 +52,12 @@ export const load: PageServerLoad = async ({ url, locals }) => {
 					},
 					currentStreak: 0,
 					bestStreak: 0,
-					recentCompletions: []
+					recentCompletions: [],
+					worstDay: null,
+					bestBook: null,
+					mostSeenBook: null,
+					totalBooksSeenOT: 0,
+					totalBooksSeenNT: 0
 				},
 				user: locals.user,
 				session: locals.session
@@ -133,6 +139,66 @@ export const load: PageServerLoad = async ({ url, locals }) => {
 				grade: getGradeFromGuesses(c.guessCount)
 			}));
 
+		// Calculate worst day (highest guess count)
+		const worstDay = completions.reduce((max, c) =>
+			c.guessCount > max.guessCount ? c : max,
+			completions[0]
+		);
+
+		// Get all daily verses to link completions to books
+		const allVerses = await db
+			.select()
+			.from(dailyVerses);
+
+		// Create a map of date -> bookId
+		const dateToBookId = new Map(allVerses.map(v => [v.date, v.bookId]));
+
+		// Calculate book-specific stats
+		const bookStats = new Map<string, { count: number; totalGuesses: number }>();
+
+		for (const completion of completions) {
+			const bookId = dateToBookId.get(completion.date);
+			if (bookId) {
+				const existing = bookStats.get(bookId) || { count: 0, totalGuesses: 0 };
+				bookStats.set(bookId, {
+					count: existing.count + 1,
+					totalGuesses: existing.totalGuesses + completion.guessCount
+				});
+			}
+		}
+
+		// Find book you know the best (lowest avg guesses)
+		let bestBook: { bookId: string; avgGuesses: number; count: number } | null = null;
+		for (const [bookId, stats] of bookStats.entries()) {
+			const avgGuesses = stats.totalGuesses / stats.count;
+			if (!bestBook || avgGuesses < bestBook.avgGuesses) {
+				bestBook = { bookId, avgGuesses, count: stats.count };
+			}
+		}
+
+		// Find most seen book
+		let mostSeenBook: { bookId: string; count: number } | null = null;
+		for (const [bookId, stats] of bookStats.entries()) {
+			if (!mostSeenBook || stats.count > mostSeenBook.count) {
+				mostSeenBook = { bookId, count: stats.count };
+			}
+		}
+
+		// Count unique books by testament
+		const oldTestamentBooks = new Set<string>();
+		const newTestamentBooks = new Set<string>();
+
+		for (const [bookId, _] of bookStats.entries()) {
+			const book = bibleBooks.find(b => b.id === bookId);
+			if (book) {
+				if (book.testament === 'old') {
+					oldTestamentBooks.add(bookId);
+				} else {
+					newTestamentBooks.add(bookId);
+				}
+			}
+		}
+
 		return {
 			stats: {
 				totalSolves,
@@ -140,7 +206,22 @@ export const load: PageServerLoad = async ({ url, locals }) => {
 				gradeDistribution,
 				currentStreak,
 				bestStreak,
-				recentCompletions
+				recentCompletions,
+				worstDay: {
+					date: worstDay.date,
+					guessCount: worstDay.guessCount
+				},
+				bestBook: bestBook ? {
+					bookId: bestBook.bookId,
+					avgGuesses: Math.round(bestBook.avgGuesses * 100) / 100,
+					count: bestBook.count
+				} : null,
+				mostSeenBook: mostSeenBook ? {
+					bookId: mostSeenBook.bookId,
+					count: mostSeenBook.count
+				} : null,
+				totalBooksSeenOT: oldTestamentBooks.size,
+				totalBooksSeenNT: newTestamentBooks.size
 			},
 			user: locals.user,
 			session: locals.session