fix: tighten diff gap stripes on the normal background

docs/editing.md

@@ -217,7 +217,7 @@ File rows show colored **A** (added, green), **M** (modified, yellow), **D** (re
 
 Changed text rows use muted red backgrounds in Before and muted green backgrounds in After, including blank tails and real empty lines. Foreground colors use the editor's bundled Tree-sitter syntax highlighting, parsed independently for each snapshot and its path (including the old path for renames). Unknown languages retain the normal foreground; historical snapshots do not borrow live-buffer LSP tokens.
 
-Missing counterparts use neutral `/` stripes instead of blank rows. Each successive aligned row shifts the stripes one column left, forming continuous diagonals; the phase follows aligned row and horizontal offset so scrolling does not restart the pattern. Actual empty source lines retain their normal/change background and are not hatched.
+Missing counterparts use muted `/` stripes on the normal terminal background instead of blank rows, with one space between slashes. Each successive aligned row shifts the stripes one column left, forming continuous diagonals; the phase follows aligned row and horizontal offset so scrolling does not restart the pattern. Actual empty source lines retain their normal/change background and are not hatched.
 
 Tab/Shift+Tab cycles focus between Files, Before, and After. In text panes, Up/Down or Ctrl+j/k scrolls both panes together; Left/Right or Ctrl+h/l scrolls the focused pane horizontally. Home/End goes to the first/last tree row or aligned text row. Wheel input over a text pane scrolls both panes; over Files it navigates visible tree rows without opening them. Esc first leaves filtering when the tree is focused; otherwise it closes the diff and preserves the editor's buffers, cursors, unsaved text, and undo history. Typing and pasted text cannot edit either snapshot.
 

src/tui.rs

@@ -1293,12 +1293,10 @@ fn draw_diff_pane(
         );
         let index = if before { row.before } else { row.after };
         let Some(index) = index else {
-            let style = Style::default()
-                .fg(Color::Rgb(72, 72, 72))
-                .bg(Color::Rgb(28, 28, 28));
+            let style = Style::default().fg(Color::Rgb(72, 72, 72)).bg(Color::Reset);
             let buffer = frame.buffer_mut();
             for x in 0..content.width {
-                let slash = (usize::from(x) % 4 + aligned_row % 4 + left % 4) % 4 == 0;
+                let slash = (usize::from(x) % 2 + aligned_row % 2 + left % 2) % 2 == 0;
                 buffer[(content.x + x, row_area.y)]
                     .set_symbol(if slash { "/" } else { " " })
                     .set_style(style);
@@ -2571,8 +2569,8 @@ mod tests {
             .map(|x| {
                 let cell = &buffer[(x, y)];
                 let column = x - after.x - 1;
-                assert_eq!(cell.symbol(), [" ", " ", " ", "/"][usize::from(column % 4)]);
-                assert_eq!(cell.bg, Color::Rgb(28, 28, 28));
+                assert_eq!(cell.symbol(), [" ", "/"][usize::from(column % 2)]);
+                assert_eq!(cell.bg, Color::Reset);
                 assert_eq!(cell.fg, Color::Rgb(72, 72, 72));
                 cell.symbol().to_owned()
             })
@@ -2622,13 +2620,9 @@ mod tests {
             for x in before.x + 1..before.right() - 1 {
                 let column = x - before.x - 1;
                 let cell = &buffer[(x, y)];
-                let pattern = if offset == 0 {
-                    ["/", " ", " ", " "]
-                } else {
-                    [" ", " ", " ", "/"]
-                };
-                assert_eq!(cell.symbol(), pattern[usize::from(column % 4)]);
-                assert_eq!(cell.bg, Color::Rgb(28, 28, 28));
+                let pattern = if offset == 0 { ["/", " "] } else { [" ", "/"] };
+                assert_eq!(cell.symbol(), pattern[usize::from(column % 2)]);
+                assert_eq!(cell.bg, Color::Reset);
                 assert_eq!(cell.fg, Color::Rgb(72, 72, 72));
             }
             assert_eq!(buffer[(after.x + 1, y)].symbol(), (offset + 1).to_string());
@@ -2650,7 +2644,7 @@ mod tests {
             let column = x - before.x - 1;
             assert_eq!(
                 buffer[(x, before.y + 1)].symbol(),
-                [" ", " ", "/", " "][usize::from(column % 4)],
+                ["/", " "][usize::from(column % 2)],
             );
         }
         assert_eq!(buffer[(before.x, before.y + 1)].symbol(), "│");