diff --git a/crates/engine/src/view_behaviour_tests.rs b/crates/engine/src/view_behaviour_tests.rs
index 9c77314e0..c470afe18 100644
--- a/crates/engine/src/view_behaviour_tests.rs
+++ b/crates/engine/src/view_behaviour_tests.rs
@@ -806,6 +806,9 @@ fn zoom_to_selection_on_a_wide_layer_is_limited_by_the_width() {
 fn zoom_to_selection_without_a_toolbar_inset_uses_the_whole_height() {
     let (v, _) = zoom_on("view.zoomSelection", 0.0, 100.0, 100.0);
     assert!((v.zoom - (903.0 - 80.0) / 100.0).abs() < 1e-6, "{}", v.zoom);
+    let (_, top) = v.page_to_screen(0.0, 0.0);
+    let (_, bottom) = v.page_to_screen(100.0, 100.0);
+    assert!((top - 40.0).abs() < 1e-6 && (bottom - 863.0).abs() < 1e-6, "top {top}, bottom {bottom}");
 }
 
 #[test]
@@ -822,6 +825,86 @@ fn zoom_to_selection_in_a_short_canvas_still_ends_above_the_toolbar() {
     let (_, bottom) = v.page_to_screen(100.0, 100.0);
     assert!(top >= 0.0 && bottom <= 70.0 + 1e-6, "top {top}, bottom {bottom}");
     assert!((top - (70.0 - bottom)).abs() < 1e-6, "centred above the toolbar: top {top}, bottom {bottom}");
+    // The margin shrinks to a quarter of the 70 points (17.5) and the zoom is the exact fit, not the floor.
+    assert!((v.zoom - 0.35).abs() < 1e-9, "{}", v.zoom);
+    assert!((top - 17.5).abs() < 1e-6 && (bottom - 52.5).abs() < 1e-6, "top {top}, bottom {bottom}");
+}
+
+/// A canvas narrower than 160 points keeps a quarter of its width on each side.
+#[test]
+fn zoom_to_selection_in_a_narrow_canvas_shrinks_the_side_margins() {
+    let mut s = Session::new();
+    let r = rect(&mut s, 0.0, 0.0, 100.0, 100.0, None);
+    ex(&mut s, "view.set", json!({"vw": 100, "vh": 903, "bottomInset": 0}));
+    ex(&mut s, "select.set", json!({"ids": [r]}));
+    ex(&mut s, "view.zoomSelection", json!({}));
+    let v = view(&s);
+    let (left, _) = v.page_to_screen(0.0, 0.0);
+    let (right, _) = v.page_to_screen(100.0, 100.0);
+    assert!((v.zoom - 0.5).abs() < 1e-9, "{}", v.zoom);
+    assert!((left - 25.0).abs() < 1e-6 && (right - 75.0).abs() < 1e-6, "left {left}, right {right}");
+}
+
+/// A view 1000 by 800 with a 100-point toolbar strip, for the edge cases of the fit.
+fn strip_view() -> ViewState {
+    ViewState { vw: 1000.0, vh: 800.0, bottom_inset: 100.0, ..ViewState::default() }
+}
+
+#[test]
+fn fitting_a_selection_survives_points_lines_extremes_and_junk() {
+    // A point: the zoom stays, and it lands in the middle of the area above the toolbar (y = 350).
+    let mut v = strip_view();
+    v.zoom = 2.0;
+    v.fit_selection(Rect::new(10.0, 20.0, 10.0, 20.0), 32.0);
+    assert_eq!(v.zoom, 2.0);
+    let (x, y) = v.page_to_screen(10.0, 20.0);
+    assert!((x - 500.0).abs() < 1e-9 && (y - 350.0).abs() < 1e-9, "{x}, {y}");
+    // A zero-width line is limited by its height, a zero-height one by its width.
+    let mut v = strip_view();
+    v.fit_selection(Rect::new(0.0, 0.0, 0.0, 100.0), 32.0);
+    assert!((v.zoom - (700.0 - 80.0) / 100.0).abs() < 1e-9, "{}", v.zoom);
+    let mut v = strip_view();
+    v.fit_selection(Rect::new(0.0, 0.0, 100.0, 0.0), 32.0);
+    assert!((v.zoom - (1000.0 - 80.0) / 100.0).abs() < 1e-9, "{}", v.zoom);
+    // A tiny one stops at the maximum zoom, a huge one at the minimum.
+    let mut v = strip_view();
+    v.fit_selection(Rect::new(0.0, 0.0, 0.001, 0.001), 32.0);
+    assert_eq!(v.zoom, 32.0);
+    v.fit_selection(Rect::new(0.0, 0.0, 1e12, 1e12), 32.0);
+    assert_eq!(v.zoom, ViewState::MIN_ZOOM);
+    // A rectangle with any coordinate that is not a finite number changes nothing.
+    for bad in [
+        Rect::new(0.0, f64::NAN, 10.0, 10.0),
+        Rect::new(0.0, 0.0, f64::INFINITY, 10.0),
+        Rect::new(0.0, 0.0, 10.0, f64::NAN),
+        Rect::new(f64::NAN, 0.0, 10.0, 10.0),
+    ] {
+        let mut v = strip_view();
+        let before = (v.zoom, v.cx, v.cy);
+        v.fit_selection(bad, 32.0);
+        assert_eq!((v.zoom, v.cx, v.cy), before, "{bad:?}");
+    }
+}
+
+#[test]
+fn the_bottom_inset_is_clamped_and_never_saved() {
+    let mut s = Session::new();
+    ex(&mut s, "view.set", json!({"bottomInset": -5}));
+    assert_eq!(view(&s).bottom_inset, 0.0);
+    ex(&mut s, "view.set", json!({"bottomInset": 1e12}));
+    assert_eq!(view(&s).bottom_inset, 20000.0);
+    // Larger than the viewport: the fit still leaves a sliver of canvas and a finite centre.
+    ex(&mut s, "view.set", json!({"vw": 400, "vh": 300, "bottomInset": 5000}));
+    let r = rect(&mut s, 0.0, 0.0, 10.0, 10.0, None);
+    ex(&mut s, "select.set", json!({"ids": [r]}));
+    ex(&mut s, "view.zoomSelection", json!({}));
+    let v = view(&s);
+    assert!(v.zoom.is_finite() && v.cx.is_finite() && v.cy.is_finite(), "{v:?}");
+    // It is not part of what the view saves.
+    let saved = serde_json::to_string(&v).unwrap();
+    assert!(!saved.to_lowercase().contains("inset"), "{saved}");
+    let back: ViewState = serde_json::from_str(&saved).unwrap();
+    assert_eq!(back.bottom_inset, 0.0);
 }
 
 #[test]
@@ -831,5 +914,8 @@ fn zoom_to_fit_is_unchanged() {
     rect(&mut s, 0.0, 0.0, 100.0, 100.0, None);
     ex(&mut s, "view.set", json!({"vw": 1389, "vh": 903, "bottomInset": 58}));
     ex(&mut s, "view.zoomFit", json!({}));
-    assert!((view(&s).zoom - (903.0 - 128.0) / 100.0).abs() < 1e-6);
+    let v = view(&s);
+    assert!((v.zoom - (903.0 - 128.0) / 100.0).abs() < 1e-6);
+    // No toolbar offset: the rectangle's own centre stays in the middle of the whole viewport.
+    assert_eq!((v.cx, v.cy), (50.0, 50.0));
 }
diff --git a/crates/engine/src/view_state.rs b/crates/engine/src/view_state.rs
index 212bb93b4..8a8cc8a01 100644
--- a/crates/engine/src/view_state.rs
+++ b/crates/engine/src/view_state.rs
@@ -113,13 +113,18 @@ impl ViewState {
     /// Fit a page rectangle for Zoom to selection: a 40 point margin on all four sides of the area
     /// above the bottom toolbar (`vw` by `vh - bottom_inset`), centred in that area.
     pub fn fit_selection(&mut self, r: figcraft_geom::Rect, max_zoom: f64) {
-        if !(r.width() > 0.0 || r.height() > 0.0) || !r.x0.is_finite() {
-            self.cx = r.center().x;
-            self.cy = r.center().y;
+        // A rectangle that isn't all finite numbers leaves the view as it is.
+        if ![r.x0, r.y0, r.x1, r.y1].iter().all(|v| v.is_finite()) {
             return;
         }
         let inset = if self.bottom_inset.is_finite() { self.bottom_inset.clamp(0.0, (self.vh - 1.0).max(0.0)) } else { 0.0 };
         let area_h = (self.vh - inset).max(1.0);
+        // A point (nothing to fit) is centred in the area above the toolbar at the zoom it has.
+        if !(r.width() > 0.0 || r.height() > 0.0) {
+            self.cx = r.center().x;
+            self.cy = r.center().y + (self.vh - area_h) / 2.0 / self.zoom.max(1e-6);
+            return;
+        }
         // 40 points as measured; a canvas too small for that keeps a quarter of its size on each
         // side instead, so the selection still ends above the toolbar.
         let mx = (self.vw / 4.0).clamp(0.0, 40.0);
diff --git a/crates/ui-egui/src/shortcuts_tests.rs b/crates/ui-egui/src/shortcuts_tests.rs
index e9c822c2b..fea6f21cd 100644
--- a/crates/ui-egui/src/shortcuts_tests.rs
+++ b/crates/ui-egui/src/shortcuts_tests.rs
@@ -91,7 +91,11 @@ fn shift_digits_zoom() {
     assert!(zoom(&u) > fit, "Shift+2 fits the smaller selection");
     let v = &u.app.session.ds().unwrap().view;
     // Centred in the canvas above the bottom toolbar: the page centre sits half the toolbar's strip lower.
-    let expect_cy = 40.0 + v.bottom_inset / 2.0 / v.zoom;
+    // The strip is the canvas's bottom edge less the pill's top, worked out here, not read back.
+    let strip = f64::from(u.app.canvas.rect.max.y - crate::toolbar::pill_rect(u.app.canvas.rect, 0.0).min.y);
+    assert!(strip > 20.0 && strip < 200.0, "the pill is a toolbar's height: {strip}");
+    assert!((v.bottom_inset - strip).abs() < 1e-3, "the app gives the engine the pill's strip: {} vs {strip}", v.bottom_inset);
+    let expect_cy = 40.0 + strip / 2.0 / v.zoom;
     assert_eq!(v.cx, 110.0, "centred on it");
     assert!((v.cy - expect_cy).abs() < 1e-9, "centred above the toolbar: {} vs {expect_cy}", v.cy);
     // `+` and `-` step the zoom.
@@ -204,3 +208,16 @@ fn shortcuts_panel_does_not_show_on_the_home_screen() {
     u.frame(vec![]);
     assert!(!u.app.ui.shortcuts_panel, "the panel closes on the home screen");
 }
+
+/// The strip the bottom toolbar covers is given to the engine while the toolbar shows and is zero
+/// when the interface is hidden.
+#[test]
+fn the_toolbar_strip_is_zero_when_the_interface_is_hidden() {
+    let (mut u, _, _) = setup();
+    u.frame(vec![]);
+    u.frame(vec![]);
+    assert!(u.app.session.ds().unwrap().view.bottom_inset > 0.0, "shown");
+    u.app.session.ds_mut().unwrap().view.ui_hidden = true;
+    u.frame(vec![]);
+    assert_eq!(u.app.session.ds().unwrap().view.bottom_inset, 0.0, "hidden");
+}