bug fixes

src/scripts/books/book.js

@@ -8,6 +8,7 @@ async function init() {
     try {
         const res = await fetch(`/api/book/${bookId}`);
         const data = await res.json();
+        console.log(data)
 
         if (data.error) {
             const titleEl = document.getElementById('title');

src/scripts/books/reader.js

@@ -448,12 +448,16 @@ document.querySelectorAll('[data-direction]').forEach(btn => {
 });
 
 prevBtn.addEventListener('click', () => {
-    const newChapter = String(parseInt(chapter) - 1);
+    const current = parseInt(chapter);
+    if (current <= 0) return;
+
+    const newChapter = String(current - 1);
     updateURL(newChapter);
     window.scrollTo(0, 0);
     loadChapter();
 });
 
+
 nextBtn.addEventListener('click', () => {
     const newChapter = String(parseInt(chapter) + 1);
     updateURL(newChapter);