Smaller touch interface: the same pixel density as on the desktop

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

src/main.rs

@@ -970,8 +970,9 @@ async fn main() {
         // pixel look: the interface on a virtual screen whose pixels are whole parts of the world's
         let rows = if [270, 360, 480].contains(&app.settings.pixel_rows) { app.settings.pixel_rows as u32 } else { 360 };
         // the interface needs room: the smallest whole multiple of the world's rows with at least
-        // 900 rows on a desktop (360 -> 1080) and 540 on a touch screen (360 -> 720)
-        let need: u32 = if touch_mode { 540 } else { 900 };
+        // 900 rows (360 -> 1080), on a desktop and on a touch screen alike (a phone has about
+        // 1080 device rows in landscape; a smaller screen draws in device pixels)
+        let need: u32 = 900;
         ui::set_virtual_rows(rows * need.div_ceil(rows));
         if touch_mode {
             // the pointer is the finger, or the position of this frame's gesture