fix(pagination): shrink window_back to 2 lines, reduce default paragraph spacing to 0

src/reader.rs

@@ -425,7 +425,7 @@ pub fn calculate_pages(text: &str, chars_per_line: usize, lines_per_page: usize)
         }
 
         if line_count >= lines_per_page && i > page_start {
-            let window_back = chars_per_line * lines_per_page / 3;
+            let window_back = chars_per_line * 2;
             let search_start = page_start.max(i.saturating_sub(window_back));
             let mut split = i;
             for j in (search_start..i).rev() {

src/style.rs

@@ -24,7 +24,7 @@ impl StyleProfile {
                 name: "Kindle 默认".into(),
                 alignment: TextAlignment::Left,
                 line_spacing: 1.8,
-                paragraph_spacing: 1.0,
+                paragraph_spacing: 0.0,
                 first_line_indent: 2.0,
                 font_size: 20.0,
             },