tweak(pagination): safety_h=1.0 to reduce underfill

src/reader.rs

@@ -6,7 +6,7 @@ use crate::theme::{self, BgType, Theme};
 pub fn recalculate_pages(book: &mut Book, font_size: f32, line_height: f32, panel_width: f32, panel_height: f32, style: &StyleProfile) {
     let char_width = font_size * 1.0;
     let safety_w = 0.95;
-    let safety_h = 0.96;
+    let safety_h = 1.0;
     let chars_per_line = if char_width > 0.0 {
         ((panel_width / char_width) * safety_w).max(1.0) as usize
     } else {

src/style.rs

@@ -56,8 +56,6 @@ impl StyleProfile {
     }
 
     pub fn line_height(&self) -> f32 {
-        // egui actual line height is approximately font_size * 1.1
-        // line_spacing adds extra (line_spacing - 1.0) * font_size * 0.5 as extra gap
         self.font_size * 1.1 + self.font_size * (self.line_spacing - 1.0).max(0.0) * 0.5
     }