fix(ui): improve desktop control sizing and spacing

nebula_app/src/gpui_shell/settings_pane.rs

@@ -33,7 +33,7 @@ use std::time::Duration;
 
 use crate::gpui_shell::config::{DEFAULT_CURSOR_BLINK, effective_cursor_blink};
 use crate::gpui_shell::prelude::*;
-use crate::gpui_shell::widgets::NebulaButton;
+use crate::gpui_shell::widgets::{NebulaButton, settings_control_height};
 
 mod about;
 mod agents;
@@ -683,7 +683,7 @@ impl SettingsPane {
                 .debug_selector(move || format!("settings-select-{key}"))
                 .w(px(SETTINGS_SELECT_WIDTH))
                 .text_color(cx.theme().link)
-                .children(select.map(|state| Select::new(&state)))
+                .children(select.map(|state| Select::new(&state).h(settings_control_height(cx))))
                 .into_any_element()
         });
         self.maybe_marked(key, label, desc, control, cx)
@@ -698,7 +698,7 @@ impl SettingsPane {
                 .w(px(SETTINGS_SELECT_WIDTH))
                 .font_family(cx.theme().mono_font_family.clone())
                 .text_color(cx.theme().link)
-                .child(Select::new(&self.shell_select)),
+                .child(Select::new(&self.shell_select).h(settings_control_height(cx))),
             cx,
         )
     }

nebula_app/src/gpui_shell/settings_pane/design.rs

@@ -127,7 +127,7 @@ impl SettingsPane {
         let reset = dirty.then(|| {
             div()
                 .id(SharedString::from(format!("setting-reset-{label}")))
-                .size(px(20.0))
+                .size(px(32.0))
                 .rounded_md()
                 .flex()
                 .items_center()
@@ -144,7 +144,7 @@ impl SettingsPane {
                     .build(window, cx)
                 })
                 .on_click(cx.listener(move |this, _, window, cx| on_reset(this, window, cx)))
-                .child(Icon::new(IconName::Undo2).xsmall())
+                .child(Icon::new(IconName::Undo2).size(px(16.0)))
                 .into_any_element()
         });
         self.row_shell(label, desc.into(), reset, dirty, RowLayout::Standard, control, cx)
@@ -239,7 +239,7 @@ impl SettingsPane {
                             Button::new(SharedString::from(format!("settings-help-{label}")))
                                 .icon(IconName::Info)
                                 .ghost()
-                                .size(px(22.0))
+                                .size(px(32.0))
                                 .text_color(theme.muted_foreground)
                                 .accessibility_id(SharedString::from(format!(
                                     "settings-help-{label}"

nebula_app/src/gpui_shell/settings_pane/segmented.rs

@@ -31,17 +31,15 @@ impl SettingsPane {
             )))
             .w(px(SETTINGS_SELECT_WIDTH))
             .max_w_full()
-            .small()
             .outline()
             .children(values.iter().copied().zip(labels).enumerate().map(
                 |(index, (value, label))| {
                     Button::new(SharedString::from(format!("settings-choice-{key}-{value}")))
                         .debug_selector(move || format!("settings-choice-{key}-{value}"))
                         .flex_1()
                         .min_w_0()
-                        .small()
-                        .h(px(28.0))
-                        .rounded(px(14.0))
+                        .h(settings_control_height(cx))
+                        .rounded(px(6.0))
                         .selected(index == selected)
                         .label(label)
                         .on_click(cx.listener(move |this, _, window, cx| {

nebula_app/src/gpui_shell/widgets.rs

@@ -16,8 +16,8 @@ use std::sync::Arc;
 
 use gpui::prelude::FluentBuilder as _;
 use gpui::{
-    App, ClickEvent, ElementId, IntoElement, ParentElement as _, RenderImage, RenderOnce,
-    SharedString, Styled as _, Window, div, px,
+    App, ClickEvent, ElementId, InteractiveElement as _, IntoElement, ParentElement as _,
+    RenderImage, RenderOnce, SharedString, Styled as _, Window, div, px,
 };
 use gpui_component::button::{Button, ButtonVariants as _};
 use gpui_component::switch::Switch;
@@ -51,6 +51,20 @@ pub fn shell_brand_image(
     Some(Arc::new(RenderImage::new([Frame::new(rgba)])))
 }
 
+/// Desktop form controls keep their padding even with a small UI font.
+pub(crate) fn settings_control_height(cx: &App) -> gpui::Pixels {
+    px(f32::from(cx.theme().font_size).max(16.0) * 2.0)
+}
+
+/// Toolbar glyphs and their hover/hit surfaces have independent logical sizes.
+pub(crate) fn toolbar_button(id: impl Into<ElementId>, icon: impl Into<Icon>) -> Button {
+    Button::new(id).icon(Icon::new(icon).size(px(18.0))).ghost().size(px(32.0))
+}
+
+#[cfg(all(test, feature = "gpui-test-support"))]
+#[path = "widgets_tests.rs"]
+mod tests;
+
 /// 设置行开关。组件库 `Switch` 的转发壳——`on_click` 与它同签名
 /// （`Fn(&bool, &mut Window, &mut App)`，参数是**点击后**的目标值）。
 #[derive(IntoElement)]
@@ -187,8 +201,12 @@ impl NebulaButton {
 }
 
 impl RenderOnce for NebulaButton {
-    fn render(self, _: &mut Window, _: &mut App) -> impl IntoElement {
+    fn render(self, _: &mut Window, cx: &mut App) -> impl IntoElement {
+        let key = self.key.clone();
         let button = Button::new(ElementId::Name(format!("nebula-btn-{}", self.key).into()))
+            .debug_selector(move || format!("nebula-btn-{key}"))
+            .h(settings_control_height(cx))
+            .px(px(12.0))
             .label(self.label)
             .disabled(self.disabled);
         // Default 走 outline：设置行里的动作按钮需要一条边把自己从行底分出来，

nebula_app/src/gpui_shell/widgets_tests.rs

@@ -0,0 +1,66 @@
+use std::{cell::Cell, rc::Rc};
+
+use gpui::{AppContext as _, Context, Modifiers, Render, TestAppContext, point};
+use gpui_component::{IconName, Root, Theme, h_flex};
+
+use super::*;
+
+struct ControlProbe(Rc<Cell<usize>>);
+
+impl Render for ControlProbe {
+    fn render(&mut self, _: &mut Window, _: &mut Context<Self>) -> impl IntoElement {
+        let action = self.0.clone();
+        let tool = self.0.clone();
+        let disabled = self.0.clone();
+        h_flex()
+            .gap(px(8.0))
+            .child(
+                NebulaButton::new("comfort-action")
+                    .label("查看详情 / Details")
+                    .on_click(move |_, _, _| action.set(action.get() + 1)),
+            )
+            .child(
+                toolbar_button("comfort-tool", IconName::Settings)
+                    .debug_selector(|| "comfort-tool".to_owned())
+                    .on_click(move |_, _, _| tool.set(tool.get() + 1)),
+            )
+            .child(
+                NebulaButton::new("comfort-disabled")
+                    .label("Disabled")
+                    .disabled(true)
+                    .on_click(move |_, _, _| disabled.set(disabled.get() + 1)),
+            )
+    }
+}
+
+#[gpui::test]
+fn desktop_controls_keep_padding_clickable_with_small_ui_fonts(cx: &mut TestAppContext) {
+    cx.update(gpui_component::init);
+    let clicks = Rc::new(Cell::new(0));
+    let (_, cx) = cx.add_window_view(|window, cx| {
+        let view = cx.new(|_| ControlProbe(clicks.clone()));
+        Root::new(view, window, cx)
+    });
+    cx.simulate_resize(gpui::size(px(1000.0), px(200.0)));
+    for (font, height) in [(10.0, 32.0), (14.0, 32.0), (24.0, 48.0)] {
+        cx.update(|window, cx| {
+            Theme::global_mut(cx).font_size = px(font);
+            window.refresh();
+            let _ = window.draw(cx);
+        });
+        let action = cx.debug_bounds("nebula-btn-comfort-action").expect("text button");
+        let tool = cx.debug_bounds("comfort-tool").expect("toolbar button");
+        let disabled = cx.debug_bounds("nebula-btn-comfort-disabled").expect("disabled button");
+        assert!(action.size.height >= px(height));
+        assert_eq!(tool.size, gpui::size(px(32.0), px(32.0)));
+        let before = clicks.get();
+        // These corners are padding, not glyphs: the whole surface must activate.
+        for bounds in [action, tool, disabled] {
+            cx.simulate_click(
+                point(bounds.origin.x + px(2.0), bounds.bottom() - px(2.0)),
+                Modifiers::default(),
+            );
+        }
+        assert_eq!(clicks.get(), before + 2, "disabled padding must not activate");
+    }
+}

nebula_app/src/gpui_shell/workspace/details_panel.rs

@@ -4,6 +4,7 @@
 use super::*;
 use crate::display::side_panel::PanelView;
 use crate::gpui_shell::file_editor::{DocumentDetails, DocumentSection, TextFileView};
+use crate::gpui_shell::widgets::toolbar_button;
 use crate::i18n::Message;
 
 #[cfg(all(test, feature = "gpui-test-support"))]
@@ -103,9 +104,7 @@ impl NebulaWorkspace {
         cx: &mut Context<Self>,
     ) -> Button {
         let visible = self.side_panel.open && !self.reader_focus_active(cx);
-        Button::new("toggle-right-sidebar")
-            .icon(IconName::PanelRight)
-            .ghost()
+        toolbar_button("toggle-right-sidebar", IconName::PanelRight)
             .disabled(disabled)
             .selected(visible)
             .when(visible, |button| button.bg(cx.theme().secondary))

nebula_app/src/gpui_shell/workspace/sidebar.rs

@@ -1,4 +1,5 @@
 use super::*;
+use crate::gpui_shell::widgets::toolbar_button;
 
 /// 折叠箭头的固定布局槽。图标是 SVG，不应借任一字体的 advance 决定留白。
 const TABS_DISCLOSURE_SLOT_W: f32 = 24.0;
@@ -871,15 +872,12 @@ impl NebulaWorkspace {
             .justify_between()
             .child(
                 h_flex()
-                    // 旧壳两枚 32px 命中块之间固定留 8px；默认 Button 正好是
-                    // 32px，`.small()` 会把热区缩成 24px。
-                    .gap_2()
+                    // Keep toolbar gaps independent of the UI font/rem size.
+                    .gap(px(8.0))
                     .items_center()
                     .occlude()
                     .child(
-                        Button::new("toggle-sidebar")
-                            .icon(IconName::PanelLeft)
-                            .ghost()
+                        toolbar_button("toggle-sidebar", IconName::PanelLeft)
                             .disabled(settings_active)
                             // 侧栏是开关而非一次性动作：展开期间必须持续显示
                             // 选中底，和旧壳 `left_sidebar_visible()` 同义。
@@ -899,9 +897,7 @@ impl NebulaWorkspace {
                             })),
                     )
                     .child(
-                        Button::new("open-settings")
-                            .icon(IconName::Settings)
-                            .ghost()
+                        toolbar_button("open-settings", IconName::Settings)
                             .selected(settings_active)
                             .when(settings_active, |button| {
                                 button.bg(settings_active_bg).text_color(settings_active_fg)
@@ -915,19 +911,18 @@ impl NebulaWorkspace {
             .child(self.render_collapsed_tab_title(cx))
             .child(
                 title_bar_panel_controls()
-                    .gap_2()
+                    .gap(px(8.0))
                     .child(
-                        Button::new("toggle-command-manager")
-                            .icon(
-                                Icon::new(Icon::empty())
-                                    .path(crate::gpui_shell::assets::nav::COMMAND_MANAGER),
-                            )
-                            .ghost()
-                            .selected(self.command_manager_open)
-                            .tooltip("命令列表")
-                            .on_click(cx.listener(|this, _, window, cx| {
-                                this.toggle_command_manager(window, cx);
-                            })),
+                        toolbar_button(
+                            "toggle-command-manager",
+                            Icon::new(Icon::empty())
+                                .path(crate::gpui_shell::assets::nav::COMMAND_MANAGER),
+                        )
+                        .selected(self.command_manager_open)
+                        .tooltip("命令列表")
+                        .on_click(cx.listener(|this, _, window, cx| {
+                            this.toggle_command_manager(window, cx);
+                        })),
                     )
                     .child(self.render_right_sidebar_button(settings_active, cx)),
             )

nebula_app/src/gpui_shell/workspace/top_tabs.rs

@@ -16,6 +16,7 @@ use gpui_component::menu::PopupMenuItem;
 
 use crate::gpui_shell::prelude::*;
 use crate::gpui_shell::terminal::view::SidebarActivity;
+use crate::gpui_shell::widgets::toolbar_button;
 
 use super::{
     NebulaWorkspace, NewWindow, OpenSettings, TAB_LABEL_ICON_SIZE, TAB_LABEL_ICON_W, TabDrag,
@@ -683,13 +684,11 @@ impl NebulaWorkspace {
             .child(
                 title_bar_panel_controls()
                     .child(
-                        Button::new("top-toggle-command-manager")
-                            .icon(
-                                Icon::new(Icon::empty()).path(
-                                    crate::gpui_shell::assets::nav::COMMAND_MANAGER,
-                                ),
-                            )
-                            .ghost()
+                        toolbar_button(
+                            "top-toggle-command-manager",
+                            Icon::new(Icon::empty())
+                                .path(crate::gpui_shell::assets::nav::COMMAND_MANAGER),
+                        )
                             .selected(self.command_manager_open)
                             .tooltip("命令列表")
                             .on_click(cx.listener(|this, _, window, cx| {