diff --git a/crates/app/src/shot.rs b/crates/app/src/shot.rs
index 8e4f29a..f0f0e98 100644
--- a/crates/app/src/shot.rs
+++ b/crates/app/src/shot.rs
@@ -90,6 +90,7 @@ enum Op {
     RegionData,
     XpsSetup,
     CraftSetup,
+    PanelControls(bool),
     XpsTab(plotx_core::state::XpsWorkbenchTab),
     /// Show a Ribbon task tab. Sets the state directly (like [`Op::XpsTab`])
     /// so the capture shows the tab's command row without the side effects a
@@ -197,6 +198,18 @@ const SCENES: &[Scene] = &[
     shot(8, "xps_diagnostics"),
     act(2, Op::CraftSetup),
     shot(8, "craft_results"),
+    act(2, Op::PanelControls(false)),
+    shot(8, "panel_controls_collapsed"),
+    act(2, Op::Resize(720.0, 700.0)),
+    shot(8, "panel_controls_narrow"),
+    act(2, Op::Resize(1440.0, 900.0)),
+    act(2, Op::PanelControls(true)),
+    shot(8, "panel_controls_expanded"),
+    Scene {
+        settle: 4,
+        op: None,
+        shot: None,
+    },
 ];
 
 pub struct ShotDriver {
@@ -379,6 +392,10 @@ fn run_op(op: Op, app: &mut PlotxApp, ctx: &egui::Context) -> Result<(), String>
         }
         Op::XpsSetup => xps_setup(app, ctx)?,
         Op::CraftSetup => craft_shot::setup(app, ctx)?,
+        Op::PanelControls(expanded) => {
+            app.session.ui.ribbon_expanded = expanded;
+            app.session.ui.craft_task_collapsed = !expanded;
+        }
         Op::XpsTab(tab) => app.session.ui.xps_workbench_tab = tab,
         Op::RibbonTab(tab) => app.session.ui.ribbon_tab = tab,
         Op::Zoom(factor) => ctx.set_zoom_factor(factor),
@@ -773,24 +790,5 @@ fn save_png(path: &Path, image: &egui::ColorImage) -> Result<(), String> {
 }
 
 #[cfg(test)]
-mod tests {
-    use super::*;
-
-    #[test]
-    fn automated_exit_bypasses_dirty_project_prompt() {
-        let mut app = PlotxApp::new_with_settings(plotx_core::settings::Settings::default());
-        app.mark_document_dirty();
-        let ctx = egui::Context::default();
-
-        let output = ctx.run_ui(egui::RawInput::default(), |ui| {
-            request_exit(&mut app, ui.ctx());
-        });
-
-        assert!(app.session.allow_close);
-        let root = output
-            .viewport_output
-            .get(&egui::ViewportId::ROOT)
-            .expect("root viewport output");
-        assert!(root.commands.contains(&egui::ViewportCommand::Close));
-    }
-}
+#[path = "shot/tests.rs"]
+mod tests;
diff --git a/crates/app/src/shot/tests.rs b/crates/app/src/shot/tests.rs
new file mode 100644
index 0000000..7cde2dd
--- /dev/null
+++ b/crates/app/src/shot/tests.rs
@@ -0,0 +1,19 @@
+use super::*;
+
+#[test]
+fn automated_exit_bypasses_dirty_project_prompt() {
+    let mut app = PlotxApp::new_with_settings(plotx_core::settings::Settings::default());
+    app.mark_document_dirty();
+    let ctx = egui::Context::default();
+
+    let output = ctx.run_ui(egui::RawInput::default(), |ui| {
+        request_exit(&mut app, ui.ctx());
+    });
+
+    assert!(app.session.allow_close);
+    let root = output
+        .viewport_output
+        .get(&egui::ViewportId::ROOT)
+        .expect("root viewport output");
+    assert!(root.commands.contains(&egui::ViewportCommand::Close));
+}
diff --git a/crates/app/src/ui/mod.rs b/crates/app/src/ui/mod.rs
index e47e927..4766cd8 100644
--- a/crates/app/src/ui/mod.rs
+++ b/crates/app/src/ui/mod.rs
@@ -22,6 +22,7 @@ mod menus;
 #[cfg(target_os = "macos")]
 pub(crate) mod native_menu;
 mod object_inspector;
+mod panel_chrome;
 mod present;
 mod primary_sidebar;
 pub(crate) mod processing_templates;
diff --git a/crates/app/src/ui/panel_chrome.rs b/crates/app/src/ui/panel_chrome.rs
new file mode 100644
index 0000000..c26d2a5
--- /dev/null
+++ b/crates/app/src/ui/panel_chrome.rs
@@ -0,0 +1,75 @@
+use egui::{Color32, Rect, Response, Sense, Stroke, StrokeKind, Ui, vec2};
+
+pub(super) const BUTTON_WIDTH: f32 = 30.0;
+
+#[derive(Clone, Copy)]
+pub(super) enum Edge {
+    Left,
+    Right,
+    Top,
+    Bottom,
+}
+
+pub(super) fn toggle(ui: &mut Ui, edge: Edge, visible: bool, label: &str) -> Response {
+    let (rect, response) = button(ui, label);
+    let color = if visible {
+        ui.style().interact(&response).text_color()
+    } else {
+        ui.visuals().weak_text_color()
+    };
+    paint_glyph(ui, rect, edge, visible, color);
+    response.on_hover_text(label)
+}
+
+pub(super) fn close(ui: &mut Ui, label: &str) -> Response {
+    ui.add_sized(
+        vec2(BUTTON_WIDTH, ui.spacing().interact_size.y),
+        egui::Button::new(egui_phosphor::regular::X).frame_when_inactive(false),
+    )
+    .on_hover_text(label)
+}
+
+fn button(ui: &mut Ui, label: &str) -> (Rect, Response) {
+    let (rect, response) = ui.allocate_exact_size(
+        vec2(BUTTON_WIDTH, ui.spacing().interact_size.y),
+        Sense::click(),
+    );
+    response.widget_info(|| {
+        egui::WidgetInfo::labeled(egui::WidgetType::Button, ui.is_enabled(), label)
+    });
+    let visuals = ui.style().interact(&response);
+    if response.hovered() || response.is_pointer_button_down_on() || response.has_focus() {
+        ui.painter()
+            .rect_filled(rect, visuals.corner_radius, visuals.weak_bg_fill);
+    }
+    (rect, response)
+}
+
+fn paint_glyph(ui: &Ui, rect: Rect, edge: Edge, filled: bool, color: Color32) {
+    let painter = ui.painter();
+    let outer = Rect::from_center_size(rect.center(), vec2(16.0, 12.0));
+    painter.rect_stroke(outer, 3.0, Stroke::new(1.2_f32, color), StrokeKind::Inside);
+    let inner = outer.shrink(2.0);
+    let band = match edge {
+        Edge::Left => Rect::from_min_size(inner.min, vec2(5.0, inner.height())),
+        Edge::Right => Rect::from_min_size(
+            inner.right_top() - vec2(5.0, 0.0),
+            vec2(5.0, inner.height()),
+        ),
+        Edge::Top => Rect::from_min_size(inner.min, vec2(inner.width(), 3.0)),
+        Edge::Bottom => Rect::from_min_size(
+            inner.left_bottom() - vec2(0.0, 3.0),
+            vec2(inner.width(), 3.0),
+        ),
+    };
+    if filled {
+        painter.rect_filled(band, 1.5, color);
+    } else {
+        painter.rect_stroke(band, 1.5, Stroke::new(1.0_f32, color), StrokeKind::Inside);
+    }
+}
+
+pub(super) fn collapse(ui: &mut Ui, collapsed: bool, name: &str) -> Response {
+    let action = if collapsed { "Expand" } else { "Collapse" };
+    toggle(ui, Edge::Bottom, !collapsed, &format!("{action} {name}"))
+}
diff --git a/crates/app/src/ui/ribbon.rs b/crates/app/src/ui/ribbon.rs
index 9116ecd..6014835 100644
--- a/crates/app/src/ui/ribbon.rs
+++ b/crates/app/src/ui/ribbon.rs
@@ -177,22 +177,16 @@ fn render_chrome_controls(
     ui: &mut Ui,
     compact_controls: bool,
 ) {
-    let collapse_label = if compact_controls {
+    let collapse = super::panel_chrome::toggle(
+        ui,
+        super::panel_chrome::Edge::Top,
+        app.session.ui.ribbon_expanded,
         if app.session.ui.ribbon_expanded {
-            icon::CARET_UP.to_owned()
+            "Collapse ribbon"
         } else {
-            icon::CARET_DOWN.to_owned()
-        }
-    } else if app.session.ui.ribbon_expanded {
-        format!("{} Collapse ribbon", icon::CARET_UP)
-    } else {
-        format!("{} Expand ribbon", icon::CARET_DOWN)
-    };
-    // The strip next to the task tabs stays quiet: chrome buttons show
-    // their frame only on hover so they read no heavier than the tabs.
-    let collapse = ui
-        .add(Button::new(collapse_label).frame_when_inactive(false))
-        .on_hover_text("Collapse or expand the ribbon command area");
+            "Expand ribbon"
+        },
+    );
     if collapse.clicked() {
         app.session.ui.ribbon_expanded = !app.session.ui.ribbon_expanded;
     }
diff --git a/crates/app/src/ui/ribbon_chrome.rs b/crates/app/src/ui/ribbon_chrome.rs
index 4539820..293aeb3 100644
--- a/crates/app/src/ui/ribbon_chrome.rs
+++ b/crates/app/src/ui/ribbon_chrome.rs
@@ -109,13 +109,6 @@ fn task_tabs_width(ui: &Ui) -> f32 {
 fn controls_width(app: &PlotxApp, ui: &Ui, compact: bool) -> f32 {
     use plotx_core::update::UpdateStatus;
 
-    let collapse = if compact {
-        icon::CARET_UP.to_owned()
-    } else if app.session.ui.ribbon_expanded {
-        format!("{} Collapse ribbon", icon::CARET_UP)
-    } else {
-        format!("{} Expand ribbon", icon::CARET_DOWN)
-    };
     let search = if compact {
         icon::MAGNIFYING_GLASS.to_owned()
     } else {
@@ -135,21 +128,21 @@ fn controls_width(app: &PlotxApp, ui: &Ui, compact: bool) -> f32 {
         _ => String::new(),
     };
     let spacing = CONTROL_SPACING;
-    [collapse, search, update]
+    [search, update]
         .into_iter()
         .filter(|text| !text.is_empty())
         .map(|text| text_width(ui, text, TextStyle::Button))
         .sum::<f32>()
-        // The two sidebar layout toggles, the separator before them, and
+        // The two sidebar toggles, Ribbon toggle, separator, and
         // their share of the item spacing.
-        + 2.0 * SIDEBAR_TOGGLE_WIDTH
+        + 3.0 * SIDEBAR_TOGGLE_WIDTH
         + 6.0
         + 5.0 * spacing
 }
 
 /// Fixed width of one sidebar layout toggle; shared with the width estimate
 /// in `controls_width` so compaction accounts for the pair.
-pub(super) const SIDEBAR_TOGGLE_WIDTH: f32 = 30.0;
+pub(super) const SIDEBAR_TOGGLE_WIDTH: f32 = super::panel_chrome::BUTTON_WIDTH;
 
 /// Fixed gap between task tabs. Command density applies only below this row,
 /// so switching tabs cannot move the task buttons or trailing chrome.
@@ -171,69 +164,17 @@ pub(super) fn sidebar_toggle_button(
     use super::commands;
 
     let command = commands::describe(app, id);
-    let sidebar_visible = command.checked == Some(true);
-    let (rect, response) = ui.allocate_exact_size(
-        egui::vec2(SIDEBAR_TOGGLE_WIDTH, ui.spacing().interact_size.y),
-        egui::Sense::click(),
-    );
-    if response.clicked() {
-        commands::execute(id, app, clipboard, ui.ctx());
-    }
-    let visuals = ui.style().interact(&response);
-    if response.hovered() || response.is_pointer_button_down_on() {
-        // Match the neighbouring frameless chrome buttons: a quiet fill that
-        // appears only under the pointer.
-        ui.painter()
-            .rect_filled(rect, visuals.corner_radius, visuals.weak_bg_fill);
-    }
-    let color = if sidebar_visible {
-        visuals.text_color()
-    } else {
-        ui.visuals().weak_text_color()
-    };
-    paint_sidebar_glyph(
-        ui,
-        rect,
-        id == commands::CommandId::TogglePrimarySidebar,
-        sidebar_visible,
-        color,
-    );
     let tip = match &command.shortcut {
         Some(shortcut) => format!("{} ({shortcut})", command.label),
         None => command.label.clone(),
     };
-    response.on_hover_text(tip);
-}
-
-fn paint_sidebar_glyph(ui: &Ui, rect: egui::Rect, left: bool, filled: bool, color: egui::Color32) {
-    let painter = ui.painter();
-    let outer = egui::Rect::from_center_size(rect.center(), egui::vec2(16.0, 12.0));
-    painter.rect_stroke(
-        outer,
-        3.0,
-        egui::Stroke::new(1.2_f32, color),
-        egui::StrokeKind::Inside,
-    );
-    let band = if left {
-        egui::Rect::from_min_max(
-            outer.min + egui::vec2(2.0, 2.0),
-            egui::pos2(outer.min.x + 7.0, outer.max.y - 2.0),
-        )
+    let edge = if id == commands::CommandId::TogglePrimarySidebar {
+        super::panel_chrome::Edge::Left
     } else {
-        egui::Rect::from_min_max(
-            egui::pos2(outer.max.x - 7.0, outer.min.y + 2.0),
-            outer.max - egui::vec2(2.0, 2.0),
-        )
+        super::panel_chrome::Edge::Right
     };
-    if filled {
-        painter.rect_filled(band, 1.5, color);
-    } else {
-        painter.rect_stroke(
-            band,
-            1.5,
-            egui::Stroke::new(1.0_f32, color),
-            egui::StrokeKind::Inside,
-        );
+    if super::panel_chrome::toggle(ui, edge, command.checked == Some(true), &tip).clicked() {
+        commands::execute(id, app, clipboard, ui.ctx());
     }
 }
 
diff --git a/crates/app/src/ui/tools/craft.rs b/crates/app/src/ui/tools/craft.rs
index 0f61ac9..90a6a95 100644
--- a/crates/app/src/ui/tools/craft.rs
+++ b/crates/app/src/ui/tools/craft.rs
@@ -1,5 +1,4 @@
 use egui::{Button, Ui};
-use egui_phosphor::regular as icon;
 use plotx_core::state::{
     CraftAnalysisIntent, CraftTaskPage, Dataset, FrameRef, PlotxApp, Selection, TaskDockTab, Tool,
 };
@@ -207,27 +206,10 @@ pub(crate) fn render_task(app: &mut PlotxApp, host: &mut Ui) {
         ui.set_width(width);
         crate::ui::card_frame(dark, egui::Margin::ZERO).show(ui, |ui| {
             task_card::header(ui, area_id, "CRAFT", None::<&str>, |ui| {
-                if ui
-                    .small_button(icon::X)
-                    .on_hover_text("Close CRAFT")
-                    .clicked()
-                {
+                if crate::ui::panel_chrome::close(ui, "Close CRAFT").clicked() {
                     close = true;
                 }
-                let glyph = if collapsed {
-                    icon::CARET_DOWN
-                } else {
-                    icon::CARET_UP
-                };
-                if ui
-                    .small_button(glyph)
-                    .on_hover_text(if collapsed {
-                        "Expand CRAFT"
-                    } else {
-                        "Collapse CRAFT"
-                    })
-                    .clicked()
-                {
+                if crate::ui::panel_chrome::collapse(ui, collapsed, "CRAFT").clicked() {
                     toggle_collapse = true;
                 }
             });
diff --git a/crates/app/src/ui/tools/curve_fit.rs b/crates/app/src/ui/tools/curve_fit.rs
index 5ca247d..8200961 100644
--- a/crates/app/src/ui/tools/curve_fit.rs
+++ b/crates/app/src/ui/tools/curve_fit.rs
@@ -82,27 +82,10 @@ pub(crate) fn render_task(app: &mut PlotxApp, host: &mut Ui) {
                 "Curve Fit",
                 Some(format!("{curve_count} · {points} points each")),
                 |ui| {
-                    if ui
-                        .small_button(icon::X)
-                        .on_hover_text("Close Curve Fit")
-                        .clicked()
-                    {
+                    if crate::ui::panel_chrome::close(ui, "Close Curve Fit").clicked() {
                         close = true;
                     }
-                    let glyph = if collapsed {
-                        icon::CARET_DOWN
-                    } else {
-                        icon::CARET_UP
-                    };
-                    if ui
-                        .small_button(glyph)
-                        .on_hover_text(if collapsed {
-                            "Expand Curve Fit"
-                        } else {
-                            "Collapse Curve Fit"
-                        })
-                        .clicked()
-                    {
+                    if crate::ui::panel_chrome::collapse(ui, collapsed, "Curve Fit").clicked() {
                         toggle_collapse = true;
                     }
                 },
diff --git a/crates/app/src/ui/tools/processing/surface.rs b/crates/app/src/ui/tools/processing/surface.rs
index bf43cd5..ac5b1d0 100644
--- a/crates/app/src/ui/tools/processing/surface.rs
+++ b/crates/app/src/ui/tools/processing/surface.rs
@@ -140,19 +140,10 @@ pub(super) fn render(app: &mut PlotxApp, host: &mut Ui) {
                 "Frequency-domain output"
             };
             task_card::header(ui, area_id, "Processing", Some(domain), |ui| {
-                if ui
-                    .small_button(icon::X)
-                    .on_hover_text("Close Processing")
-                    .clicked()
-                {
+                if crate::ui::panel_chrome::close(ui, "Close Processing").clicked() {
                     close = true;
                 }
-                let glyph = if collapsed {
-                    icon::CARET_DOWN
-                } else {
-                    icon::CARET_UP
-                };
-                if ui.small_button(glyph).clicked() {
+                if crate::ui::panel_chrome::collapse(ui, collapsed, "Processing").clicked() {
                     toggle = true;
                 }
                 ui.menu_button(icon::DOTS_THREE_VERTICAL, |ui| panel_menu(app, di, ui));
@@ -238,19 +229,10 @@ fn render_xrd(app: &mut PlotxApp, host: &mut Ui, di: usize) {
         ui.set_width(width);
         crate::ui::card_frame(dark, egui::Margin::ZERO).show(ui, |ui| {
             task_card::header(ui, area_id, "XRD Processing", None::<&str>, |ui| {
-                if ui
-                    .small_button(icon::X)
-                    .on_hover_text("Close Processing")
-                    .clicked()
-                {
+                if crate::ui::panel_chrome::close(ui, "Close Processing").clicked() {
                     close = true;
                 }
-                let glyph = if collapsed {
-                    icon::CARET_DOWN
-                } else {
-                    icon::CARET_UP
-                };
-                if ui.small_button(glyph).clicked() {
+                if crate::ui::panel_chrome::collapse(ui, collapsed, "Processing").clicked() {
                     toggle = true;
                 }
                 ui.menu_button(icon::DOTS_THREE_VERTICAL, |ui| panel_menu(app, di, ui));
diff --git a/crates/app/src/ui/tools/region_analysis.rs b/crates/app/src/ui/tools/region_analysis.rs
index 2d6fe2f..d64e58c 100644
--- a/crates/app/src/ui/tools/region_analysis.rs
+++ b/crates/app/src/ui/tools/region_analysis.rs
@@ -93,27 +93,10 @@ pub(crate) fn render_task(app: &mut PlotxApp, host: &mut Ui) {
                 format!("{count} regions")
             };
             task_card::header(ui, area_id, "Regions", Some(state), |ui| {
-                if ui
-                    .small_button(icon::X)
-                    .on_hover_text("Close region tools")
-                    .clicked()
-                {
+                if crate::ui::panel_chrome::close(ui, "Close region tools").clicked() {
                     close = true;
                 }
-                let glyph = if collapsed {
-                    icon::CARET_DOWN
-                } else {
-                    icon::CARET_UP
-                };
-                if ui
-                    .small_button(glyph)
-                    .on_hover_text(if collapsed {
-                        "Expand region tools"
-                    } else {
-                        "Collapse region tools"
-                    })
-                    .clicked()
-                {
+                if crate::ui::panel_chrome::collapse(ui, collapsed, "region tools").clicked() {
                     toggle_collapse = true;
                 }
                 if collapsed
diff --git a/crates/app/src/ui/tools/statistics.rs b/crates/app/src/ui/tools/statistics.rs
index 02c7dfc..7d9525e 100644
--- a/crates/app/src/ui/tools/statistics.rs
+++ b/crates/app/src/ui/tools/statistics.rs
@@ -83,27 +83,10 @@ pub(crate) fn render_task(app: &mut PlotxApp, host: &mut Ui) {
                 "Statistics",
                 Some(format!("{columns} columns · {points} rows")),
                 |ui| {
-                    if ui
-                        .small_button(icon::X)
-                        .on_hover_text("Close Statistics")
-                        .clicked()
-                    {
+                    if crate::ui::panel_chrome::close(ui, "Close Statistics").clicked() {
                         close = true;
                     }
-                    let glyph = if collapsed {
-                        icon::CARET_DOWN
-                    } else {
-                        icon::CARET_UP
-                    };
-                    if ui
-                        .small_button(glyph)
-                        .on_hover_text(if collapsed {
-                            "Expand Statistics"
-                        } else {
-                            "Collapse Statistics"
-                        })
-                        .clicked()
-                    {
+                    if crate::ui::panel_chrome::collapse(ui, collapsed, "Statistics").clicked() {
                         toggle_collapse = true;
                     }
                 },
diff --git a/docs/src/content/docs/reference/ribbon.md b/docs/src/content/docs/reference/ribbon.md
index 26f90f5..5ae2e68 100644
--- a/docs/src/content/docs/reference/ribbon.md
+++ b/docs/src/content/docs/reference/ribbon.md
@@ -49,7 +49,7 @@ The Ribbon measures the active tab's content against the window:
   lower priority, and every group keeps its position.
 - Only when every group is already a single button and the row still does not
   fit do whole groups move into the **More** menu.
-- The command area never hides by itself. **Collapse ribbon** (the caret at
+- The command area never hides by itself. **Collapse ribbon** (the window icon with a top band at
   the right end of the task row) puts it away and brings it back.
 
 Buttons that start a computation, such as **Run Peak Fit**, use the filled
diff --git a/docs/src/content/docs/reference/ui-overview.md b/docs/src/content/docs/reference/ui-overview.md
index 8418b18..3b7b593 100644
--- a/docs/src/content/docs/reference/ui-overview.md
+++ b/docs/src/content/docs/reference/ui-overview.md
@@ -45,6 +45,10 @@ buttons at the right end of the Ribbon's task row, press
 (right; <kbd>Cmd</kbd> on macOS), or drag a Side Bar's inner edge past its
 minimum width to hide it.
 
+The Ribbon's show/hide button uses the same window-outline style, with a band
+at the top. Task cards use a bottom band for their body; a filled band means
+the region is visible. Closing a task card remains a separate **×** button.
+
 ## Recurring elements
 
 - **Figure panel (Panel)** — a labelled section of a figure that can contain
diff --git a/docs/src/content/docs/zh-cn/reference/ribbon.md b/docs/src/content/docs/zh-cn/reference/ribbon.md
index d04b641..9b56c47 100644
--- a/docs/src/content/docs/zh-cn/reference/ribbon.md
+++ b/docs/src/content/docs/zh-cn/reference/ribbon.md
@@ -42,7 +42,7 @@ Ribbon 以活动页签的内容对照窗口宽度实测：
   一个带组名的按钮，点击即在弹出面板中展开整组。任何分组都不会比优先级更低的
   分组缩得更小，且每个分组始终留在原位。
 - 只有当所有分组都已折成单个按钮而仍然放不下时，整组才会移入 **More** 菜单。
-- 命令区不会自行隐藏。**Collapse ribbon**（任务行右端的箭头）负责收起与
+- 命令区不会自行隐藏。**Collapse ribbon**（任务行右端带顶部条带的窗口图标）负责收起与
   展开。
 
 启动计算的按钮（如 **Run Peak Fit**）使用强调色填充样式——与任务卡片的
diff --git a/docs/src/content/docs/zh-cn/reference/ui-overview.md b/docs/src/content/docs/zh-cn/reference/ui-overview.md
index 89ee82a..66509b2 100644
--- a/docs/src/content/docs/zh-cn/reference/ui-overview.md
+++ b/docs/src/content/docs/zh-cn/reference/ui-overview.md
@@ -38,6 +38,10 @@ PlotX 的界面为英文；手册中加粗的英文词即界面上的原文标
 <kbd>Ctrl</kbd>+<kbd>B</kbd>（左）或 <kbd>Ctrl</kbd>+<kbd>Shift</kbd>+<kbd>B</kbd>
 （右；macOS 上为 <kbd>Cmd</kbd>），或把侧栏内缘拖过其最小宽度即可将其隐藏。
 
+Ribbon 的显示/隐藏按钮沿用相同的窗口轮廓样式，顶部条带表示命令区。
+任务卡片使用底部条带表示内容区；实心条带表示该区域可见。
+关闭任务卡片仍使用独立的 **×** 按钮。
+
 ## 常见元素
 
 - **图版面板（Panel）**——图版中带标签的分区，可以包含图表、图片、文本与形状。