fix: refine thumbnail spacing and indicate excerpt overflow

src/main.rs

@@ -17,9 +17,9 @@
 //! Esc closes the popup; j/k loads the selected video's description and i returns to editing.
 //! Normal-mode t toggles a thumbnail in the same-sized popup; j/k follows selection, Esc closes.
 //! Images use native terminal graphics when supported, otherwise colored half-block characters.
-//! Thumbnails scale proportionally in the left pane without cropping.
-//! The right pane has a bold title above a dimmed author · publication date and description excerpt.
-//! Text wraps two columns before the right border; the excerpt is clipped to the remaining height.
+//! Thumbnails scale proportionally in the left pane, aligned one column from the text.
+//! A blank row separates the bold title from the dimmed author · publication date.
+//! Text retains a two-column right gutter; overflowing excerpts end with … without splitting wide glyphs.
 //! Both previews share asynchronous full-description fetching and per-video caching.
 //! curl fetches JPEGs lazily into memory; decoding and image resizing/encoding run off-thread.
 //! Channel tags live in `$XDG_CONFIG_HOME/tubular/config.toml`, or `~/.config/tubular/config.toml`.
@@ -1027,13 +1027,14 @@ impl App {
             let block = Block::bordered().border_style(Style::new().fg(Color::Cyan));
             let [image, _, mut details] = Layout::horizontal([
                 Constraint::Fill(3),
-                Constraint::Length(2),
+                Constraint::Length(1),
                 Constraint::Fill(2),
             ])
             .areas(block.inner(popup));
             details.width = details.width.saturating_sub(2);
             let metadata = Paragraph::new(vec![
                 Line::raw(video.title.as_str()).bold(),
+                Line::default(),
                 Line::from(vec![
                     video.channel.as_deref().unwrap_or("Unknown").into(),
                     " · ".into(),
@@ -1067,10 +1068,40 @@ impl App {
                     .as_deref()
                     .unwrap_or("Loading full description..."),
             };
-            frame.render_widget(
-                Paragraph::new(description).wrap(Wrap { trim: false }).dim(),
-                excerpt,
-            );
+            let paragraph = Paragraph::new(description).wrap(Wrap { trim: false }).dim();
+            let overflow = video
+                .description
+                .as_deref()
+                .is_some_and(|text| !text.is_empty())
+                && !excerpt.is_empty()
+                && paragraph.line_count(excerpt.width) > usize::from(excerpt.height);
+            frame.render_widget(paragraph, excerpt);
+            if overflow {
+                let buffer = frame.buffer_mut();
+                let y = excerpt.bottom() - 1;
+                let end = (excerpt.x..excerpt.right())
+                    .rev()
+                    .find_map(|x| {
+                        let symbol = buffer
+                            .cell((x, y))
+                            .expect("excerpt is inside frame")
+                            .symbol();
+                        (!symbol.trim().is_empty())
+                            .then(|| x.saturating_add(Span::raw(symbol).width() as u16))
+                    })
+                    .unwrap_or(excerpt.x);
+                let mut x = end.min(excerpt.right() - 1);
+                // Do not leave half of a wide character beneath the ellipsis.
+                if x > excerpt.x && Span::raw(buffer.cell((x - 1, y)).unwrap().symbol()).width() > 1
+                {
+                    x -= 1;
+                }
+                buffer
+                    .cell_mut((x, y))
+                    .unwrap()
+                    .set_symbol("…")
+                    .set_style(Style::new().dim());
+            }
             // Drawing polls completion and starts resize work before we choose the title state.
             self.thumbnail.draw(frame, image);
             frame.render_widget(
@@ -1278,6 +1309,55 @@ mod tests {
         )
     }
 
+    #[test]
+    fn thumbnail_ellipsis_marks_only_hidden_content_and_preserves_wide_characters() {
+        use ratatui::{Terminal, backend::TestBackend};
+
+        let mut app = app(&["tubular"]);
+        app.views[0].videos = youtube::search_results(
+            r#"{"entries":[{"id":"jNQXAC9IVRw","title":"Heading","channel":"Creator","upload_date":"20050423"}]}"#,
+        ).unwrap().videos;
+        app.views[0].selection.select(Some(0));
+        app.thumbnail_open = true;
+        for (last_line, hidden, marker) in [
+            ("line", false, None),
+            ("line", true, Some(50)),
+            ("abcdefghijklmnopqrs", true, Some(64)),
+            ("a界界界界界界界界界", true, Some(63)),
+            ("", true, Some(46)),
+        ] {
+            app.views[0].videos[0].description = Some(format!(
+                "{}{last_line}{}",
+                "line\n".repeat(6),
+                if hidden { "\nhidden content" } else { "" },
+            ));
+            let mut terminal = Terminal::new(TestBackend::new(80, 24)).unwrap();
+            terminal
+                .draw(|frame| app.draw(frame, Duration::ZERO))
+                .unwrap();
+            let buffer = terminal.backend().buffer();
+            // The blank row separates the title from its byline.
+            for x in 46..65 {
+                assert_eq!(buffer.cell((x, 7)).unwrap().symbol(), " ");
+            }
+            assert_eq!(buffer.cell((46, 8)).unwrap().symbol(), "C");
+            if let Some(x) = marker {
+                assert_eq!(buffer.cell((x, 17)).unwrap().symbol(), "…");
+                if last_line.starts_with("a界") {
+                    assert_eq!(buffer.cell((61, 17)).unwrap().symbol(), "界");
+                    assert_eq!(buffer.cell((64, 17)).unwrap().symbol(), " ");
+                }
+            } else {
+                let row: String = (46..65)
+                    .map(|x| buffer.cell((x, 17)).unwrap().symbol())
+                    .collect();
+                assert_eq!(row.trim_end(), "line");
+            }
+            assert_eq!(buffer.cell((65, 17)).unwrap().symbol(), " ");
+            assert_eq!(buffer.cell((66, 17)).unwrap().symbol(), " ");
+        }
+    }
+
     #[test]
     fn thumbnail_text_has_contrast_a_right_gutter_and_a_clipped_excerpt() {
         use ratatui::{Terminal, backend::TestBackend, style::Modifier};