diff --git a/Cargo.lock b/Cargo.lock
index a4f8826..6ee9349 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -661,7 +661,7 @@ dependencies = [
 [[package]]
 name = "build_helpers"
 version = "0.14.0"
-source = "git+https://github.com/pop-os/libcosmic?rev=03d7dcb832bc6d15bc1bb07327a1aa426b2d5bc0#03d7dcb832bc6d15bc1bb07327a1aa426b2d5bc0"
+source = "git+https://github.com/ferese-wm/libcosmic?tag=ferese-v0.1.0#9e7b137321cc197eca5034470031ab4896781048"
 dependencies = [
  "cfg_aliases",
 ]
@@ -902,7 +902,7 @@ checksum = "fe6d2e5af09e8c8ad56c969f2157a3d4238cebc7c55f0a517728c38f7b200f81"
 dependencies = [
  "serde",
  "termcolor",
- "unicode-width 0.2.2",
+ "unicode-width 0.1.14",
 ]
 
 [[package]]
@@ -1034,7 +1034,7 @@ dependencies = [
 [[package]]
 name = "cosmic-config"
 version = "1.0.0"
-source = "git+https://github.com/pop-os/libcosmic?rev=03d7dcb832bc6d15bc1bb07327a1aa426b2d5bc0#03d7dcb832bc6d15bc1bb07327a1aa426b2d5bc0"
+source = "git+https://github.com/ferese-wm/libcosmic?tag=ferese-v0.1.0#9e7b137321cc197eca5034470031ab4896781048"
 dependencies = [
  "atomicwrites",
  "cosmic-config-derive",
@@ -1055,7 +1055,7 @@ dependencies = [
 [[package]]
 name = "cosmic-config-derive"
 version = "1.0.0"
-source = "git+https://github.com/pop-os/libcosmic?rev=03d7dcb832bc6d15bc1bb07327a1aa426b2d5bc0#03d7dcb832bc6d15bc1bb07327a1aa426b2d5bc0"
+source = "git+https://github.com/ferese-wm/libcosmic?tag=ferese-v0.1.0#9e7b137321cc197eca5034470031ab4896781048"
 dependencies = [
  "quote",
  "syn 2.0.119",
@@ -1124,7 +1124,7 @@ dependencies = [
 [[package]]
 name = "cosmic-theme"
 version = "1.0.0"
-source = "git+https://github.com/pop-os/libcosmic?rev=03d7dcb832bc6d15bc1bb07327a1aa426b2d5bc0#03d7dcb832bc6d15bc1bb07327a1aa426b2d5bc0"
+source = "git+https://github.com/ferese-wm/libcosmic?tag=ferese-v0.1.0#9e7b137321cc197eca5034470031ab4896781048"
 dependencies = [
  "almost",
  "configparser",
@@ -1655,6 +1655,7 @@ dependencies = [
  "ferese-ipc",
  "ferese-layout",
  "ferese-protocols",
+ "ferese-shape",
  "fontdb",
  "futures-lite",
  "image",
@@ -1782,6 +1783,11 @@ dependencies = [
  "zeroize",
 ]
 
+[[package]]
+name = "ferese-shape"
+version = "0.1.0"
+source = "git+https://github.com/ferese-wm/ferese-shape?tag=v0.1.0#63d7b6dfd520dd882fc493d3272e26029ae0c9b8"
+
 [[package]]
 name = "ferese-shell"
 version = "0.1.0"
@@ -2617,7 +2623,7 @@ dependencies = [
 [[package]]
 name = "iced"
 version = "0.14.0"
-source = "git+https://github.com/pop-os/libcosmic?rev=03d7dcb832bc6d15bc1bb07327a1aa426b2d5bc0#03d7dcb832bc6d15bc1bb07327a1aa426b2d5bc0"
+source = "git+https://github.com/ferese-wm/libcosmic?tag=ferese-v0.1.0#9e7b137321cc197eca5034470031ab4896781048"
 dependencies = [
  "build_helpers",
  "dnd",
@@ -2639,7 +2645,7 @@ dependencies = [
 [[package]]
 name = "iced_accessibility"
 version = "0.1.0"
-source = "git+https://github.com/pop-os/libcosmic?rev=03d7dcb832bc6d15bc1bb07327a1aa426b2d5bc0#03d7dcb832bc6d15bc1bb07327a1aa426b2d5bc0"
+source = "git+https://github.com/ferese-wm/libcosmic?tag=ferese-v0.1.0#9e7b137321cc197eca5034470031ab4896781048"
 dependencies = [
  "accesskit",
  "accesskit_winit",
@@ -2648,13 +2654,14 @@ dependencies = [
 [[package]]
 name = "iced_core"
 version = "0.14.0"
-source = "git+https://github.com/pop-os/libcosmic?rev=03d7dcb832bc6d15bc1bb07327a1aa426b2d5bc0#03d7dcb832bc6d15bc1bb07327a1aa426b2d5bc0"
+source = "git+https://github.com/ferese-wm/libcosmic?tag=ferese-v0.1.0#9e7b137321cc197eca5034470031ab4896781048"
 dependencies = [
  "bitflags 2.13.2",
  "build_helpers",
  "bytes",
  "cosmic-client-toolkit",
  "dnd",
+ "ferese-shape",
  "glam",
  "iced_accessibility",
  "lilt",
@@ -2675,7 +2682,7 @@ dependencies = [
 [[package]]
 name = "iced_debug"
 version = "0.14.0"
-source = "git+https://github.com/pop-os/libcosmic?rev=03d7dcb832bc6d15bc1bb07327a1aa426b2d5bc0#03d7dcb832bc6d15bc1bb07327a1aa426b2d5bc0"
+source = "git+https://github.com/ferese-wm/libcosmic?tag=ferese-v0.1.0#9e7b137321cc197eca5034470031ab4896781048"
 dependencies = [
  "iced_core",
  "iced_futures",
@@ -2685,7 +2692,7 @@ dependencies = [
 [[package]]
 name = "iced_futures"
 version = "0.14.0"
-source = "git+https://github.com/pop-os/libcosmic?rev=03d7dcb832bc6d15bc1bb07327a1aa426b2d5bc0#03d7dcb832bc6d15bc1bb07327a1aa426b2d5bc0"
+source = "git+https://github.com/ferese-wm/libcosmic?tag=ferese-v0.1.0#9e7b137321cc197eca5034470031ab4896781048"
 dependencies = [
  "futures",
  "iced_core",
@@ -2699,7 +2706,7 @@ dependencies = [
 [[package]]
 name = "iced_graphics"
 version = "0.14.0"
-source = "git+https://github.com/pop-os/libcosmic?rev=03d7dcb832bc6d15bc1bb07327a1aa426b2d5bc0#03d7dcb832bc6d15bc1bb07327a1aa426b2d5bc0"
+source = "git+https://github.com/ferese-wm/libcosmic?tag=ferese-v0.1.0#9e7b137321cc197eca5034470031ab4896781048"
 dependencies = [
  "bitflags 2.13.2",
  "bytemuck",
@@ -2720,7 +2727,7 @@ dependencies = [
 [[package]]
 name = "iced_program"
 version = "0.14.0"
-source = "git+https://github.com/pop-os/libcosmic?rev=03d7dcb832bc6d15bc1bb07327a1aa426b2d5bc0#03d7dcb832bc6d15bc1bb07327a1aa426b2d5bc0"
+source = "git+https://github.com/ferese-wm/libcosmic?tag=ferese-v0.1.0#9e7b137321cc197eca5034470031ab4896781048"
 dependencies = [
  "iced_graphics",
  "iced_runtime",
@@ -2729,7 +2736,7 @@ dependencies = [
 [[package]]
 name = "iced_renderer"
 version = "0.14.0"
-source = "git+https://github.com/pop-os/libcosmic?rev=03d7dcb832bc6d15bc1bb07327a1aa426b2d5bc0#03d7dcb832bc6d15bc1bb07327a1aa426b2d5bc0"
+source = "git+https://github.com/ferese-wm/libcosmic?tag=ferese-v0.1.0#9e7b137321cc197eca5034470031ab4896781048"
 dependencies = [
  "iced_graphics",
  "iced_tiny_skia",
@@ -2741,7 +2748,7 @@ dependencies = [
 [[package]]
 name = "iced_runtime"
 version = "0.14.0"
-source = "git+https://github.com/pop-os/libcosmic?rev=03d7dcb832bc6d15bc1bb07327a1aa426b2d5bc0#03d7dcb832bc6d15bc1bb07327a1aa426b2d5bc0"
+source = "git+https://github.com/ferese-wm/libcosmic?tag=ferese-v0.1.0#9e7b137321cc197eca5034470031ab4896781048"
 dependencies = [
  "build_helpers",
  "bytes",
@@ -2758,7 +2765,7 @@ dependencies = [
 [[package]]
 name = "iced_tiny_skia"
 version = "0.14.0"
-source = "git+https://github.com/pop-os/libcosmic?rev=03d7dcb832bc6d15bc1bb07327a1aa426b2d5bc0#03d7dcb832bc6d15bc1bb07327a1aa426b2d5bc0"
+source = "git+https://github.com/ferese-wm/libcosmic?tag=ferese-v0.1.0#9e7b137321cc197eca5034470031ab4896781048"
 dependencies = [
  "bytemuck",
  "cosmic-text",
@@ -2775,7 +2782,7 @@ dependencies = [
 [[package]]
 name = "iced_wgpu"
 version = "0.14.0"
-source = "git+https://github.com/pop-os/libcosmic?rev=03d7dcb832bc6d15bc1bb07327a1aa426b2d5bc0#03d7dcb832bc6d15bc1bb07327a1aa426b2d5bc0"
+source = "git+https://github.com/ferese-wm/libcosmic?tag=ferese-v0.1.0#9e7b137321cc197eca5034470031ab4896781048"
 dependencies = [
  "as-raw-xcb-connection",
  "bitflags 2.13.2",
@@ -2807,7 +2814,7 @@ dependencies = [
 [[package]]
 name = "iced_widget"
 version = "0.14.2"
-source = "git+https://github.com/pop-os/libcosmic?rev=03d7dcb832bc6d15bc1bb07327a1aa426b2d5bc0#03d7dcb832bc6d15bc1bb07327a1aa426b2d5bc0"
+source = "git+https://github.com/ferese-wm/libcosmic?tag=ferese-v0.1.0#9e7b137321cc197eca5034470031ab4896781048"
 dependencies = [
  "build_helpers",
  "cosmic-client-toolkit",
@@ -2827,7 +2834,7 @@ dependencies = [
 [[package]]
 name = "iced_winit"
 version = "0.14.0"
-source = "git+https://github.com/pop-os/libcosmic?rev=03d7dcb832bc6d15bc1bb07327a1aa426b2d5bc0#03d7dcb832bc6d15bc1bb07327a1aa426b2d5bc0"
+source = "git+https://github.com/ferese-wm/libcosmic?tag=ferese-v0.1.0#9e7b137321cc197eca5034470031ab4896781048"
 dependencies = [
  "build_helpers",
  "cosmic-client-toolkit",
@@ -3358,7 +3365,7 @@ checksum = "3eaf3ede3fee6db1a4c2ee091bf8a8b4dccdc6d17f656fb07896ee72867612f2"
 [[package]]
 name = "libcosmic"
 version = "1.0.0"
-source = "git+https://github.com/pop-os/libcosmic?rev=03d7dcb832bc6d15bc1bb07327a1aa426b2d5bc0#03d7dcb832bc6d15bc1bb07327a1aa426b2d5bc0"
+source = "git+https://github.com/ferese-wm/libcosmic?tag=ferese-v0.1.0#9e7b137321cc197eca5034470031ab4896781048"
 dependencies = [
  "apply",
  "ashpd 0.12.3",
diff --git a/Cargo.toml b/Cargo.toml
index dd66ff5..7501eaa 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -26,11 +26,12 @@ license = "MIT"
 rust-version = "1.95"
 
 [workspace.dependencies]
+ferese-shape = { git = "https://github.com/ferese-wm/ferese-shape", tag = "v0.1.0" }
 bitflags = "2.9.4"
 calloop = { version = "0.14.4", features = ["signals"] }
 jiff = "0.2.37"
 libc = "0.2.176"
-libcosmic = { git = "https://github.com/pop-os/libcosmic", rev = "03d7dcb832bc6d15bc1bb07327a1aa426b2d5bc0", default-features = false, features = ["multi-window", "tokio", "wayland"] }
+libcosmic = { git = "https://github.com/ferese-wm/libcosmic", tag = "ferese-v0.1.0", default-features = false, features = ["multi-window", "tokio", "wayland"] }
 smithay = { version = "0.7.0", default-features = false, features = [
     "backend_drm",
     "backend_gbm",
diff --git a/README.md b/README.md
index db48978..caaff40 100644
--- a/README.md
+++ b/README.md
@@ -25,7 +25,7 @@ Ferese combines a window manager and desktop shell with one configuration.
 - [Continuum motion](docs/configuration.md#animations): interruptible springs, gesture momentum and motion settings shared by the compositor and shell
 - Multiple monitors with fractional scaling and automatic refresh-rate switching on low battery
 - Themes, wallpapers and blur that update live, with Light/Dark/Auto modes and custom KDL themes
-- Squircle window corners with matching borders and shadows
+- Squircle window and shell corners with matching borders, shadows and blur masks
 - Desktop widgets, including a clock and sticky notes
 - Screenshots with annotation, screen sharing and built-in recording
 - A built-in lock screen and authentication dialogs
diff --git a/compositor/Cargo.toml b/compositor/Cargo.toml
index 57913ea..1de664e 100644
--- a/compositor/Cargo.toml
+++ b/compositor/Cargo.toml
@@ -6,6 +6,7 @@ license.workspace = true
 rust-version.workspace = true
 
 [dependencies]
+ferese-shape.workspace = true
 ferese-config = { path = "../crates/ferese-config" }
 ab_glyph = "0.2.32"
 fontdb = "0.23.0"
diff --git a/compositor/src/presentation.rs b/compositor/src/presentation.rs
index a2c23d8..c70d2a9 100644
--- a/compositor/src/presentation.rs
+++ b/compositor/src/presentation.rs
@@ -146,12 +146,7 @@ pub(crate) fn physical_rect(
     )
 }
 
-#[derive(Clone, Copy, Debug, Default, PartialEq, Eq)]
-pub(crate) enum CornerShape {
-    #[default]
-    Circular,
-    Continuous,
-}
+pub(crate) use ferese_shape::Shape as CornerShape;
 
 /// Conservative extent of the corner shoulders, in physical pixels.
 pub(crate) fn corner_extent(radius: f32, size: smithay::utils::Size<i32, Physical>, shape: CornerShape) -> f32 {
diff --git a/compositor/src/render/corner_tests.rs b/compositor/src/render/corner_tests.rs
index e5145a8..4da6adb 100644
--- a/compositor/src/render/corner_tests.rs
+++ b/compositor/src/render/corner_tests.rs
@@ -153,28 +153,50 @@ fn coverage(distance: f64) -> f64 {
 }
 
 #[test]
-fn shell_roles_and_shader_sources_keep_circular_corners() {
-    use crate::effects::SemanticRole::*;
+fn shared_geometry_matches_the_existing_window_profile() {
+    let bounds = [1.25, 2.5, 61.5, 59.0];
 
-    for role in [Panel, PanelElevated, Popover, Menu, Notification, Hud, Modal] {
-        assert_eq!(corner_shape_for_role(Some(role)), CornerShape::Circular);
+    for shape in [CornerShape::Circular, CornerShape::Continuous] {
+        for radius in [0.0, 0.375, 8.25, 12.375, 24.0, 29.49, 29.5] {
+            let outline = ferese_shape::Outline::new(bounds, [radius; 4], shape).unwrap();
+
+            for y in 0..64 {
+                for x in 0..64 {
+                    let point = [x as f64 + 0.5, y as f64 + 0.5];
+                    let expected = reference_distance(point, bounds, radius, shape);
+                    let actual = outline.signed_distance(point);
+                    assert!(
+                        (actual - expected).abs() < 0.01,
+                        "{shape:?} radius={radius} point={point:?}"
+                    );
+                    assert!((coverage(actual) - coverage(expected)).abs() <= 2.0 / 255.0);
+                }
+            }
+        }
     }
+}
 
-    assert_eq!(corner_shape_for_role(None), CornerShape::Continuous);
-
+#[test]
+fn shell_masks_match_the_shared_squircle_profile() {
     for source in [BLUR_SHADER, MATERIAL_SHADER, ROUNDED_TEXTURE_SHADER] {
         assert_eq!(
             corner_shader(source),
-            source.replace("//_CORNERS_", include_str!("shaders/corners.glsl"))
+            corner_shader_for(source, CornerShape::Continuous)
         );
-        assert!(!corner_shader(source).contains("CORNER_EXTENT"));
+        assert!(corner_shader(source).contains("CORNER_EXTENT"));
+        assert!(!corner_shader_for(source, CornerShape::Circular).contains("CORNER_EXTENT"));
     }
 }
 
 fn renderer() -> GlesRenderer {
     use smithay::backend::egl::{EGLContext, EGLDevice, EGLDisplay};
 
-    let device = EGLDevice::enumerate().unwrap().last().expect("an EGL device");
+    let devices = EGLDevice::enumerate().unwrap().collect::<Vec<_>>();
+    let software = std::env::var_os("FERESE_TEST_EGL_SOFTWARE").is_some();
+    let device = devices
+        .into_iter()
+        .find(|device| device.is_software() == software)
+        .expect("the requested EGL device");
     let display = unsafe { EGLDisplay::new(device).unwrap() };
     unsafe { GlesRenderer::new(EGLContext::new(&display).unwrap()).unwrap() }
 }
@@ -334,12 +356,12 @@ fn apple_window_fill_and_inset_border_match_path_reference_at_fractional_scales(
 
 #[test]
 #[ignore = "requires an EGL rendering device"]
-fn window_programs_do_not_change_cached_shell_materials_and_blur() {
+fn circular_and_squircle_programs_keep_independent_caches() {
     let mut renderer = renderer();
     let mut resources = RenderResources::default();
     let context = renderer.context_id().erased();
-    let circular = rounded_clip_program(&mut resources, &mut renderer).unwrap();
-    material_program(&mut resources, &mut renderer).unwrap();
+    let circular = corner_program(&mut resources, &mut renderer, CornerShape::Circular).unwrap();
+    material_program_for_corners(&mut resources, &mut renderer, CornerShape::Circular).unwrap();
     blur_program(&mut resources, &mut renderer).unwrap();
     let uniforms = [
         Uniform::new("clip_rect", [0.0f32, 0.0, 64.0, 64.0]),
@@ -349,7 +371,7 @@ fn window_programs_do_not_change_cached_shell_materials_and_blur() {
     let before = rasterize(&mut renderer, &circular.solid, &uniforms);
     corner_program(&mut resources, &mut renderer, CornerShape::Continuous).unwrap();
     material_program_for_corners(&mut resources, &mut renderer, CornerShape::Continuous).unwrap();
-    let circular = rounded_clip_program(&mut resources, &mut renderer).unwrap();
+    let circular = corner_program(&mut resources, &mut renderer, CornerShape::Circular).unwrap();
     let after = rasterize(&mut renderer, &circular.solid, &uniforms);
     assert_eq!(before, after);
     let cache = &resources.contexts[&context];
@@ -550,3 +572,57 @@ fn measured_uikit_profile_has_flat_shoulders_but_small_internal_join_discontinui
         assert!((curvature_jump - 0.354_989_57).abs() < 1.0e-6);
     }
 }
+
+#[test]
+#[ignore = "manual EGL timing; optional FERESE_CORNER_REFERENCE_SHADER path"]
+fn corner_heavy_shader_timing_sample() {
+    use smithay::backend::renderer::gles::{UniformName, UniformType};
+    let mut renderer = renderer();
+    let reference = std::env::var_os("FERESE_CORNER_REFERENCE_SHADER")
+        .map(|path| std::fs::read_to_string(path).expect("reference GLSL"));
+    let current = include_str!("shaders/window_corners.glsl");
+    let size = (1024, 768).into();
+    let rect = Rectangle::<i32, Physical>::from_size(size);
+    let mut texture: GlesTexture = renderer.create_buffer(Fourcc::Abgr8888, (1024, 768).into()).unwrap();
+    let body = "\nvoid main() { float d = rounded_rect_distance(mod(gl_FragCoord.xy, vec2(64.0)), vec4(0.0, 0.0, 64.0, 64.0), radius); gl_FragColor = vec4(edge_coverage(d)); }";
+    for (name, source) in reference
+        .as_deref()
+        .map(|s| ("reference", s))
+        .into_iter()
+        .chain([("optimized", current)])
+    {
+        let shader = format!("precision highp float; uniform float radius;\n{source}{body}");
+        let program = renderer
+            .compile_custom_pixel_shader(shader, &[UniformName::new("radius", UniformType::_1f)])
+            .unwrap();
+        for radius in [8.0f32, 16.0, 24.0] {
+            let mut samples = Vec::new();
+            for i in 0..110 {
+                let start = std::time::Instant::now();
+                let mut target = renderer.bind(&mut texture).unwrap();
+                let mut frame = renderer.render(&mut target, size, Transform::Normal).unwrap();
+                frame.clear(Color32F::TRANSPARENT, &[rect]).unwrap();
+                frame
+                    .render_pixel_shader_to(
+                        &program,
+                        Rectangle::from_size((1024.0, 768.0).into()),
+                        rect,
+                        (1024, 768).into(),
+                        Some(&[rect]),
+                        1.0,
+                        &[Uniform::new("radius", radius)],
+                    )
+                    .unwrap();
+                frame.finish().unwrap().wait().unwrap();
+                if i >= 10 {
+                    samples.push(start.elapsed());
+                }
+            }
+            samples.sort_unstable();
+            eprintln!(
+                "corner-heavy {name} radius={radius}: median={:?}, p95={:?}",
+                samples[50], samples[95]
+            );
+        }
+    }
+}
diff --git a/compositor/src/render/decorations.rs b/compositor/src/render/decorations.rs
index 832e37d..56c1341 100644
--- a/compositor/src/render/decorations.rs
+++ b/compositor/src/render/decorations.rs
@@ -4,7 +4,7 @@ pub(super) fn rounded_clip_program(
     resources: &mut RenderResources,
     renderer: &mut GlesRenderer,
 ) -> Option<RoundedClipPrograms> {
-    corner_program(resources, renderer, CornerShape::Circular)
+    corner_program(resources, renderer, CornerShape::Continuous)
 }
 
 pub(super) fn corner_program(
diff --git a/compositor/src/render/materials.rs b/compositor/src/render/materials.rs
index 7df6a78..02fea8e 100644
--- a/compositor/src/render/materials.rs
+++ b/compositor/src/render/materials.rs
@@ -428,7 +428,7 @@ pub(super) fn material_program(
     resources: &mut RenderResources,
     renderer: &mut GlesRenderer,
 ) -> Option<MaterialProgram> {
-    material_program_for_corners(resources, renderer, CornerShape::Circular)
+    material_program_for_corners(resources, renderer, CornerShape::Continuous)
 }
 
 pub(super) fn material_program_for_corners(
diff --git a/compositor/src/render/mod.rs b/compositor/src/render/mod.rs
index b882e6c..d7d46bb 100644
--- a/compositor/src/render/mod.rs
+++ b/compositor/src/render/mod.rs
@@ -119,7 +119,7 @@ const MATERIAL_SHADER: &str = include_str!("shaders/material_shader.frag");
 const BLUR_SHADER: &str = include_str!("shaders/blur_shader.frag");
 
 fn corner_shader(source: &str) -> String {
-    corner_shader_for(source, CornerShape::Circular)
+    corner_shader_for(source, CornerShape::Continuous)
 }
 
 fn corner_shader_for(source: &str, shape: CornerShape) -> String {
@@ -137,21 +137,9 @@ fn corner_shader_for(source: &str, shape: CornerShape) -> String {
     }
 }
 
-pub(crate) fn window_corner_shape(window: &smithay::desktop::Window) -> CornerShape {
-    // Semantic shell surfaces keep their client-matching circular outlines.
-    corner_shape_for_role(
-        window
-            .toplevel()
-            .and_then(|toplevel| crate::effects::surface_role(toplevel.wl_surface()).map(|(role, _)| role)),
-    )
-}
-
-fn corner_shape_for_role(role: Option<crate::effects::SemanticRole>) -> CornerShape {
-    if role.is_some() {
-        CornerShape::Circular
-    } else {
-        CornerShape::Continuous
-    }
+pub(crate) fn window_corner_shape(_window: &smithay::desktop::Window) -> CornerShape {
+    // Shell surfaces and application windows use the same shared squircle profile.
+    CornerShape::Continuous
 }
 
 #[derive(Clone, Debug)]
diff --git a/compositor/src/render/shaders/material_shader.frag b/compositor/src/render/shaders/material_shader.frag
index 4e5603e..b26d989 100644
--- a/compositor/src/render/shaders/material_shader.frag
+++ b/compositor/src/render/shaders/material_shader.frag
@@ -15,6 +15,9 @@ void main() {
     float sdf = rounded_rect_distance(gl_FragCoord.xy, visible_rect, material_radius);
     float coverage = edge_coverage(sdf);
     if (paint_mode > 0.5) {
+        // The shadow pass is multiplied by (1 - coverage). Fully covered
+        // pixels need neither a second contour solve nor a Gaussian sample.
+        if (coverage >= 1.0) { gl_FragColor = vec4(0.0); return; }
         float distance = max(rounded_rect_distance(gl_FragCoord.xy, shadow_rect, material_radius), 0.0);
         float sigma = max(shadow_values.x * 0.5, 0.5);
         float opacity = exp(-0.5 * distance * distance / (sigma * sigma))
diff --git a/compositor/src/render/shaders/rounded_border_shader.frag b/compositor/src/render/shaders/rounded_border_shader.frag
index a359c23..902898f 100644
--- a/compositor/src/render/shaders/rounded_border_shader.frag
+++ b/compositor/src/render/shaders/rounded_border_shader.frag
@@ -26,7 +26,7 @@ void main() {
 
 #ifdef CONTINUOUS_WINDOW_CORNERS
     // Inset the outer distance field along its normals, rather than shrinking
-    // the quartic's bounding box/radius and changing border thickness.
+    // the profile's bounding box/radius and changing border thickness.
     float inner_coverage = edge_coverage(signed_distance + border_width);
 #else
     vec2 inner_size = max(clip_rect.zw - vec2(2.0 * border_width), vec2(0.0));
diff --git a/compositor/src/render/shaders/window_corners.glsl b/compositor/src/render/shaders/window_corners.glsl
index 8843dba..69e22ad 100644
--- a/compositor/src/render/shaders/window_corners.glsl
+++ b/compositor/src/render/shaders/window_corners.glsl
@@ -44,7 +44,11 @@ float corner_nearest(vec2 query, float t, vec2 a, vec2 b, vec2 c, vec2 d) {
         vec2 error = point - query;
         float speed_squared = dot(tangent, tangent);
         float denominator = max(speed_squared + dot(error, acceleration), speed_squared * 0.25);
-        t = clamp(t - clamp(dot(error, tangent) / denominator, -0.25, 0.25), 0.0, 1.0);
+        float next = clamp(t - clamp(dot(error, tangent) / denominator, -0.25, 0.25), 0.0, 1.0);
+        if (next == t) {
+            break;
+        }
+        t = next;
     }
 
     return t;
@@ -71,13 +75,23 @@ float rounded_rect_distance(vec2 point, vec4 rect, float radius) {
         return -min(inset.x, inset.y);
     }
 
-    vec2 query = inset / radius;
+    // Reflect onto the first half of the symmetric corner. The opposite
+    // shoulder cannot be nearer than its reflection, so omit segment 2.
+    vec2 query = vec2(min(inset.x, inset.y), max(inset.x, inset.y)) / radius;
     float best_squared = 1.0e20;
     float side = 1.0;
 
-    for (int segment = 0; segment < 3; segment++) {
+    for (int segment = 0; segment < 2; segment++) {
         vec2 a, b, c, d;
         corner_controls(segment, blend, a, b, c, d);
+        // The cubic stays inside its control hull. Reject only when even
+        // that hull's box cannot improve the closest point found so far.
+        vec2 low = min(min(a, b), min(c, d));
+        vec2 high = max(max(a, b), max(c, d));
+        vec2 delta = max(max(low - query, query - high), 0.0);
+        if (dot(delta, delta) > best_squared) {
+            continue;
+        }
 
         for (int seed = 0; seed < 2; seed++) {
             float t = corner_nearest(query, float(seed), a, b, c, d);
diff --git a/crates/ferese-theme/Cargo.toml b/crates/ferese-theme/Cargo.toml
index ae71748..73d3be3 100644
--- a/crates/ferese-theme/Cargo.toml
+++ b/crates/ferese-theme/Cargo.toml
@@ -10,7 +10,7 @@ jiff.workspace = true
 ferese-theme-model = { path = "../ferese-theme-model" }
 libcosmic = { workspace = true, features = ["a11y"] }
 
-iced_accessibility = { git = "https://github.com/pop-os/libcosmic", rev = "03d7dcb832bc6d15bc1bb07327a1aa426b2d5bc0" }
+iced_accessibility = { git = "https://github.com/ferese-wm/libcosmic", tag = "ferese-v0.1.0" }
 
 [dev-dependencies]
 ferese-config = { path = "../ferese-config" }
diff --git a/crates/ferese-theme/src/button.rs b/crates/ferese-theme/src/button.rs
index 2d3a6ab..dd48234 100644
--- a/crates/ferese-theme/src/button.rs
+++ b/crates/ferese-theme/src/button.rs
@@ -1,3 +1,4 @@
+use cosmic::iced::border::Shape as BorderShape;
 use cosmic::iced::{Background, Color};
 use cosmic::theme;
 use cosmic::widget::button;
@@ -27,6 +28,8 @@ pub(crate) fn accent_button_style(theme: &cosmic::Theme, state: State, focused:
     let background = composite(fill, native.primary(false).base.into());
     let foreground = foreground(background, component.on.into());
     button::Style {
+        shape: Some(BorderShape::Continuous),
+        outline: None,
         background: Some(Background::Color(background)),
         text_color: Some(foreground),
         icon_color: Some(foreground),
diff --git a/crates/ferese-theme/src/calendar.rs b/crates/ferese-theme/src/calendar.rs
index 8f839e4..7196db6 100644
--- a/crates/ferese-theme/src/calendar.rs
+++ b/crates/ferese-theme/src/calendar.rs
@@ -1,4 +1,5 @@
 //! Date/time labels and a calendar grid; callers own navigation and popup behavior.
+use cosmic::iced::border::Shape as BorderShape;
 use cosmic::iced::{Alignment, Background, Border, Length};
 use cosmic::widget::{column, container, row};
 use cosmic::{Element, theme};
@@ -124,6 +125,7 @@ pub fn grid<'a, M: Clone + 'a>(
                 .class(theme::Container::custom(move |_| container::Style {
                     background: is_today.then_some(Background::Color(palette.accent.scale_alpha(0.2 * opacity))),
                     border: Border {
+                        shape: BorderShape::Continuous,
                         radius: palette.radius.min(12.).into(),
                         ..Default::default()
                     },
diff --git a/crates/ferese-theme/src/controls.rs b/crates/ferese-theme/src/controls.rs
index a08e581..77fb528 100644
--- a/crates/ferese-theme/src/controls.rs
+++ b/crates/ferese-theme/src/controls.rs
@@ -1,3 +1,4 @@
+use cosmic::iced::border::Shape as BorderShape;
 use cosmic::iced::{Background, Border, Color, Vector};
 use cosmic::widget::{button, container};
 use cosmic::{theme, widget};
@@ -66,6 +67,8 @@ pub fn text_button<'a, M: Clone + 'a>(
 
 pub fn switch<'a, M: Clone + 'a>(enabled: bool, palette: Palette) -> button::Button<'a, M> {
     let paint = move |focused| button::Style {
+        shape: Some(BorderShape::Continuous),
+        outline: None,
         background: None,
         text_color: Some(palette.text),
         icon_color: Some(palette.text),
@@ -100,6 +103,8 @@ pub fn navigation_style(p: Palette, selected: bool) -> theme::Button {
 
 pub fn settings_input(p: Palette) -> theme::TextInput {
     let appearance = move |focused: bool, hovered: bool| cosmic::widget::text_input::Appearance {
+        shape: Some(BorderShape::Continuous),
+        outline: None,
         background: mix(p.card, p.text, if hovered { 0.06 } else { 0.035 }).into(),
         border_radius: p.radius.min(7.).into(),
         border_width: 1.,
@@ -133,9 +138,11 @@ pub fn select<'a, M: 'a>(
     widget::container(content).class(theme::Container::custom(move |_| container::Style {
         background: Some(mix(p.card, p.text, 0.035).into()),
         border: Border {
+            shape: BorderShape::Continuous,
             width: 1.,
             color: mix(p.card, p.text, 0.18),
             radius: p.radius.min(7.).into(),
+            ..Default::default()
         },
         ..Default::default()
     }))
@@ -170,6 +177,8 @@ fn styled_button(p: Palette, selected: bool, navigation: bool, opacity: f32, foc
         };
 
         button::Style {
+            shape: Some(BorderShape::Continuous),
+            outline: None,
             background: Some(Background::Color(background)),
             text_color: Some(on),
             icon_color: Some(on),
@@ -208,6 +217,8 @@ pub fn authentication_button(palette: Palette) -> theme::Button {
             (crate::composite(palette.card, palette.background), palette.muted)
         };
         button::Style {
+            shape: Some(BorderShape::Continuous),
+            outline: None,
             background: Some(Background::Color(fill)),
             text_color: Some(foreground),
             icon_color: Some(foreground),
@@ -231,6 +242,8 @@ pub fn authentication_input(palette: Palette) -> theme::TextInput {
     let accent = palette.accent;
     let radius = palette.radius.min(10.);
     let appearance = move |focused: bool| widget::text_input::Appearance {
+        shape: Some(BorderShape::Continuous),
+        outline: None,
         background: Color::from_rgba(text.r, text.g, text.b, 0.045).into(),
         border_radius: radius.into(),
         border_width: 1.,
@@ -258,6 +271,8 @@ pub fn authentication_input(palette: Palette) -> theme::TextInput {
 
 pub fn lock_input(radius: f32, accent: cosmic::iced::Color, surface: cosmic::iced::Color) -> theme::TextInput {
     let appearance = move |focused: bool| widget::text_input::Appearance {
+        shape: Some(BorderShape::Continuous),
+        outline: None,
         background: cosmic::iced::Color::from_rgba(
             (surface.r + 1.) * 0.5,
             (surface.g + 1.) * 0.5,
@@ -299,6 +314,8 @@ pub fn shell_button(
     pressed: bool,
 ) -> button::Style {
     button::Style {
+        shape: Some(BorderShape::Continuous),
+        outline: None,
         text_color: Some(foreground),
         icon_color: Some(foreground),
         border_radius: radius.into(),
@@ -318,6 +335,7 @@ pub fn surface_appearance(background: Color, radius: f32) -> container::Style {
     container::Style {
         background: Some(Background::Color(background)),
         border: Border {
+            shape: BorderShape::Continuous,
             radius: radius.into(),
             ..Default::default()
         },
@@ -327,6 +345,8 @@ pub fn surface_appearance(background: Color, radius: f32) -> container::Style {
 
 pub fn notification_button(foreground: Color, hover: Color, radius: f32, filled: bool) -> theme::Button {
     let style = move |active: bool| button::Style {
+        shape: Some(BorderShape::Continuous),
+        outline: None,
         text_color: Some(foreground),
         icon_color: Some(foreground),
         background: (active || filled).then_some(Background::Color(hover)),
@@ -343,6 +363,8 @@ pub fn notification_button(foreground: Color, hover: Color, radius: f32, filled:
 
 pub fn filled_button(fill: Color, foreground: Color, radius: f32, opacity: f32) -> theme::Button {
     let paint = move |outline| button::Style {
+        shape: Some(BorderShape::Continuous),
+        outline: None,
         background: Some(Color { a: opacity, ..fill }.into()),
         text_color: Some(foreground),
         icon_color: Some(foreground),
diff --git a/crates/ferese-theme/src/gallery.rs b/crates/ferese-theme/src/gallery.rs
index f7b830e..0283cfc 100644
--- a/crates/ferese-theme/src/gallery.rs
+++ b/crates/ferese-theme/src/gallery.rs
@@ -1,5 +1,6 @@
 use cosmic::iced::advanced::widget::{Id, Operation, Tree, tree};
 use cosmic::iced::advanced::{Clipboard, Layout, Shell, Widget, layout, mouse, renderer};
+use cosmic::iced::border::Shape as BorderShape;
 use cosmic::iced::{Event, Length, Rectangle, Size, keyboard};
 use cosmic::{Element, Renderer, Theme};
 use ferese_theme_model::Appearance;
@@ -65,6 +66,8 @@ pub fn tile<M: Clone + 'static>(
 
 fn tile_style(palette: crate::Palette, selected: bool) -> cosmic::theme::Button {
     let style = move |focused: bool, hovered: bool| cosmic::widget::button::Style {
+        shape: Some(BorderShape::Continuous),
+        outline: None,
         background: Some(if hovered { palette.sidebar } else { palette.card }.into()),
         border_width: if selected { 2. } else { 0. },
         border_color: palette.accent,
@@ -395,9 +398,11 @@ impl<M: Clone> Widget<M, Theme, Renderer> for Radio<'_, M> {
                 renderer::Quad {
                     bounds: layout.bounds(),
                     border: cosmic::iced::Border {
+                        shape: BorderShape::Continuous,
                         color: style.text_color,
                         width: 2.,
                         radius: 10.into(),
+                        ..Default::default()
                     },
                     ..Default::default()
                 },
diff --git a/crates/ferese-theme/src/geometry.rs b/crates/ferese-theme/src/geometry.rs
index 629a2b2..05096b2 100644
--- a/crates/ferese-theme/src/geometry.rs
+++ b/crates/ferese-theme/src/geometry.rs
@@ -1,4 +1,4 @@
-/// Radius of a concentric inset, in the same units as the outer radius.
+/// Radius of a circular inset. Squircle insets retain an `Outline` and its distance offset.
 pub fn inner_radius(outer: f32, padding: f32) -> f32 {
     (outer - padding).max(0.0)
 }
diff --git a/crates/ferese-theme/src/menus.rs b/crates/ferese-theme/src/menus.rs
index 2fa268e..cf7b2e5 100644
--- a/crates/ferese-theme/src/menus.rs
+++ b/crates/ferese-theme/src/menus.rs
@@ -1,5 +1,6 @@
 //! Shared menu layouts and paint; callers own actions and animation timing.
 use cosmic::Element;
+use cosmic::iced::border::Shape as BorderShape;
 use cosmic::iced::{Alignment, Color, Length};
 use cosmic::widget::{button, container, row as iced_row};
 
@@ -115,11 +116,13 @@ pub fn slider(foreground: Color, opacity: f32) -> cosmic::theme::iced::Slider {
                 ),
                 width: 4.,
                 border: cosmic::iced::Border {
+                    shape: BorderShape::Continuous,
                     radius: 2.into(),
                     ..Default::default()
                 },
             },
             handle: Handle {
+                corner_shape: BorderShape::Circular,
                 shape: HandleShape::Circle { radius: 6. },
                 background: foreground.into(),
                 border_width: 0.,
diff --git a/crates/ferese-theme/src/palette.rs b/crates/ferese-theme/src/palette.rs
index 63209ff..69533c7 100644
--- a/crates/ferese-theme/src/palette.rs
+++ b/crates/ferese-theme/src/palette.rs
@@ -1,4 +1,5 @@
 use cosmic::iced::Color;
+use cosmic::iced::border::Shape as BorderShape;
 
 #[derive(Clone, Copy, Debug, PartialEq)]
 pub struct Palette {
@@ -68,8 +69,9 @@ impl Palette {
             .text_tint(rgba(self.text).color)
             .accent(rgba(self.accent).color)
             .build();
+
         crate::apply(&mut native, self.on_accent);
-        cosmic::Theme::custom(std::sync::Arc::new(native))
+        cosmic::Theme::custom(std::sync::Arc::new(native)).corner_shape(BorderShape::Continuous)
     }
 
     pub fn application_style(self, background: Color) -> cosmic::iced::theme::Style {
@@ -135,7 +137,9 @@ mod tests {
                 resolved.accessibility.increase_contrast = high_contrast;
                 let palette = Palette::from_resolved(&resolved);
                 assert_eq!(palette.high_contrast, high_contrast);
-                assert_eq!(palette.native_theme().cosmic().is_high_contrast, high_contrast);
+                let native = palette.native_theme();
+                assert_eq!(native.cosmic().is_high_contrast, high_contrast);
+                assert_eq!(native.corner_shape, BorderShape::Continuous);
             }
         }
     }
diff --git a/docs/configuration.md b/docs/configuration.md
index f1fef4d..fad2f7b 100644
--- a/docs/configuration.md
+++ b/docs/configuration.md
@@ -193,7 +193,7 @@ Live windows, overview thumbnails and retained images share a window identity
 and presentation state. Entering overview inherits the window's visible position
 and velocity, including motion from a workspace slide. Resize images use the same
 content mapping in overview and remain visible if the window closes during a resize.
-Content, clipping and borders use the same rounded rectangle at the output's scale.
+Content, clipping and borders use the same squircle outline at the output's scale.
 
 ### Spring tuning
 
@@ -837,7 +837,10 @@ Text input is available by default; Ctrl+Alt+Escape releases an active shortcut
 inhibitor. Use `feresectl --help` for runtime control commands.
 
 Shell rounding is controlled in Settings → Appearance → Shell corner radius.
-Small controls cap the radius to fit their size. Window rounding remains under
+The shell and compositor use the same squircle profile for fills, borders, shadows
+and blur masks. Small controls cap the radius to fit their size; circles and pills
+keep circular outlines. The measured profile has small tangent and curvature
+discontinuities at its internal segment joins. Window rounding remains under
 Settings → Windows. `theme.geometry.shell-radius` takes precedence over the old
 `appearance.corner-radius` and then `theme.geometry.top-bar-radius` keys; when
 none are set, the shell uses 14 px. Legacy clock/note radius fields no longer
diff --git a/shell/ferese-lock/src/main.rs b/shell/ferese-lock/src/main.rs
index 9a12d8c..0d79e69 100644
--- a/shell/ferese-lock/src/main.rs
+++ b/shell/ferese-lock/src/main.rs
@@ -457,9 +457,11 @@ impl Locker {
                     text_color: Some(on),
                     icon_color: Some(on),
                     border: iced::Border {
+                        shape: cosmic::iced::border::Shape::Continuous,
                         radius: (avatar_size / 2.).into(),
                         width: 1.,
                         color: a.accent.scale_alpha(0.3),
+                        ..Default::default()
                     },
                     ..Default::default()
                 }
diff --git a/shell/ferese-settings/src/main.rs b/shell/ferese-settings/src/main.rs
index b70b68a..0d23334 100644
--- a/shell/ferese-settings/src/main.rs
+++ b/shell/ferese-settings/src/main.rs
@@ -1130,6 +1130,120 @@ mod tests {
         }
     }
 
+    #[test]
+    #[ignore = "release scroll/render sample; requires both renderer backends"]
+    fn profile_dense_pages_on_both_renderers() {
+        use cosmic::iced::advanced::renderer::{Headless, Renderer as _};
+        use cosmic::iced::advanced::{Layout, Shell, clipboard, layout, mouse, renderer, widget::Tree};
+        use cosmic::iced::{Color, Event, Font, Pixels, Point, Rectangle, Size};
+        let runtime = tokio::runtime::Builder::new_current_thread()
+            .enable_all()
+            .build()
+            .unwrap();
+        let bounds = Rectangle::with_size(Size::new(1000.0, 780.0));
+        let scale = 1.25;
+        let size = Size::new(1250, 975);
+
+        for backend in ["wgpu", "tiny-skia"] {
+            let mut renderer = runtime
+                .block_on(<cosmic::Renderer as Headless>::new(
+                    Font::default(),
+                    Pixels(14.0),
+                    Some(backend),
+                ))
+                .expect("requested renderer");
+            eprintln!("renderer={}", Headless::name(&renderer));
+
+            for page in [Page::Shortcuts, Page::Appearance] {
+                let mut app = shortcuts(500);
+                app.page = page;
+                let theme = app.native_palette.native_theme();
+                let mut tree: Option<Tree> = None;
+                let mut samples = Vec::new();
+
+                for frame in 0..48 {
+                    let mut messages = Vec::new();
+                    let mut clipboard = clipboard::Null;
+                    let mut shell = Shell::new(&mut messages);
+                    let cursor = mouse::Cursor::Available(Point::new(700.0, 450.0));
+                    let started = std::time::Instant::now();
+                    let mut view = app.page_view();
+                    let tree = tree.get_or_insert_with(|| Tree::new(view.as_widget()));
+                    tree.diff(view.as_widget_mut());
+                    let node =
+                        view.as_widget_mut()
+                            .layout(tree, &renderer, &layout::Limits::new(Size::ZERO, bounds.size()));
+                    view.as_widget_mut().update(
+                        tree,
+                        &Event::Mouse(mouse::Event::WheelScrolled {
+                            delta: mouse::ScrollDelta::Lines {
+                                x: 0.0,
+                                y: if frame < 24 { -1.0 } else { 1.0 },
+                            },
+                        }),
+                        Layout::new(&node),
+                        cursor,
+                        &renderer,
+                        &mut clipboard,
+                        &mut shell,
+                        &bounds,
+                    );
+                    let layout_elapsed = started.elapsed();
+                    renderer.reset(bounds);
+                    let draw_started = std::time::Instant::now();
+                    view.as_widget().draw(
+                        tree,
+                        &mut renderer,
+                        &theme,
+                        &renderer::Style {
+                            text_color: Color::WHITE,
+                            icon_color: Color::WHITE,
+                            scale_factor: scale as f64,
+                        },
+                        Layout::new(&node),
+                        cursor,
+                        &bounds,
+                    );
+                    let draw_elapsed = draw_started.elapsed();
+                    drop(view);
+                    let render_started = std::time::Instant::now();
+                    let pixels = Headless::screenshot(&mut renderer, size, scale, theme.cosmic().bg_color().into());
+                    std::hint::black_box(pixels);
+                    let render_elapsed = render_started.elapsed();
+
+                    for message in messages {
+                        let _ = app.update(message);
+                    }
+
+                    if frame >= 8 {
+                        samples.push((
+                            layout_elapsed.as_micros(),
+                            draw_elapsed.as_micros(),
+                            render_elapsed.as_micros(),
+                        ));
+                    }
+                }
+
+                for (stage, index) in [("layout", 0), ("draw_queue", 1), ("render_and_readback", 2)] {
+                    let mut times = samples
+                        .iter()
+                        .map(|sample| match index {
+                            0 => sample.0,
+                            1 => sample.1,
+                            _ => sample.2,
+                        })
+                        .collect::<Vec<_>>();
+                    times.sort_unstable();
+                    eprintln!(
+                        "backend={backend} page={page:?} stage={stage} median_us={} p95_us={}",
+                        times[times.len() / 2],
+                        times[times.len() * 95 / 100]
+                    );
+                }
+            }
+        }
+    }
+
     #[test]
     fn disabling_auto_keeps_the_effective_appearance() {
         for appearance in [
diff --git a/shell/ferese-shell/Cargo.toml b/shell/ferese-shell/Cargo.toml
index 8dbf911..1cb40e9 100644
--- a/shell/ferese-shell/Cargo.toml
+++ b/shell/ferese-shell/Cargo.toml
@@ -17,7 +17,7 @@ libc.workspace = true
 # Keep GPU rendering available as a fallback/override. The shell defaults to
 # tiny-skia to avoid a second GPU initialization during desktop startup.
 libcosmic = { workspace = true, features = ["wgpu", "a11y"] }
-iced_accessibility = { git = "https://github.com/pop-os/libcosmic", rev = "03d7dcb832bc6d15bc1bb07327a1aa426b2d5bc0" }
+iced_accessibility = { git = "https://github.com/ferese-wm/libcosmic", tag = "ferese-v0.1.0" }
 serde.workspace = true
 serde_json.workspace = true
 tempfile.workspace = true
diff --git a/shell/ferese-shell/src/bar.rs b/shell/ferese-shell/src/bar.rs
index db2bf90..86462d9 100644
--- a/shell/ferese-shell/src/bar.rs
+++ b/shell/ferese-shell/src/bar.rs
@@ -2,6 +2,7 @@ use super::{
     Background, BarMetrics, Border, Color, Element, FereseShell, Length, Message, ShellSnapshot, ShellTheme, alignment,
     bar_icon, button, color, color_with_opacity, container, control, motion, row, status_ui, text, theme, window,
 };
+use cosmic::iced::border::Shape as BorderShape;
 
 impl FereseShell {
     pub(super) fn output_for_bar(&self, id: window::Id) -> Option<&control::OutputSnapshot> {
@@ -327,9 +328,11 @@ pub(super) fn workspace_selector_style(
             None
         },
         border: Border {
+            shape: BorderShape::Continuous,
             color: color_with_opacity(shell_theme.accent, 0.55),
             width: if active_elsewhere { 1.0 } else { 0.0 },
             radius: shell_theme.material_radius.min(14.0).into(),
+            ..Default::default()
         },
         ..Default::default()
     }
@@ -350,9 +353,11 @@ pub(super) fn bar_group_style(theme: ShellTheme) -> container::Style {
     container::Style {
         background: Some(Background::Color(color_with_opacity(theme.border, 0.25))),
         border: Border {
+            shape: BorderShape::Continuous,
             color: color(theme.border),
             width: 1.0,
             radius: theme.material_radius.min(16.0).into(),
+            ..Default::default()
         },
         ..Default::default()
     }
diff --git a/shell/ferese-shell/src/desktop_widgets.rs b/shell/ferese-shell/src/desktop_widgets.rs
index a71e599..a3e4b01 100644
--- a/shell/ferese-shell/src/desktop_widgets.rs
+++ b/shell/ferese-shell/src/desktop_widgets.rs
@@ -4,6 +4,7 @@ use super::{
     configured_font, container, destroy_layer_surface, format_bar_time, motion, note_store, row, set_anchor,
     set_margin, stacked_clock_digits, text, theme, window,
 };
+use cosmic::iced::border::Shape as BorderShape;
 
 impl FereseShell {
     pub(super) fn flush_note_changes(&mut self) -> Task<Message> {
@@ -398,6 +399,7 @@ impl FereseShell {
             .class(theme::Container::custom(move |_| container::Style {
                 background,
                 border: Border {
+                    shape: BorderShape::Continuous,
                     radius: radius.into(),
                     ..Default::default()
                 },
@@ -613,6 +615,7 @@ impl FereseShell {
             .class(theme::Container::custom(move |_| container::Style {
                 background,
                 border: Border {
+                    shape: BorderShape::Continuous,
                     radius: radius.into(),
                     ..Default::default()
                 },
diff --git a/shell/ferese-shell/src/notification_ui.rs b/shell/ferese-shell/src/notification_ui.rs
index c6fd5af..9090134 100644
--- a/shell/ferese-shell/src/notification_ui.rs
+++ b/shell/ferese-shell/src/notification_ui.rs
@@ -1,3 +1,4 @@
+use cosmic::iced::border::Shape as BorderShape;
 use cosmic::iced::widget::scrollable::{Direction, Scrollbar};
 use cosmic::widget::{column, scrollable};
 
@@ -56,6 +57,23 @@ fn card_button<'a>(
         .into()
 }
 
+fn card_surface<'a>(
+    content: impl Into<Element<'a, cosmic::Action<Message>>>,
+    history: bool,
+    style: container::Style,
+) -> Element<'a, cosmic::Action<Message>> {
+    container(content)
+        .id(if history {
+            "ferese-history-card"
+        } else {
+            "ferese-blur-card"
+        })
+        .width(Length::Fill)
+        .clip_to_border(true)
+        .class(theme::Container::custom(move |_| style))
+        .into()
+}
+
 fn icon_control<'a>(
     source: &'static [u8],
     label: &'static str,
@@ -82,6 +100,7 @@ fn icon_control<'a>(
     .class(theme::Container::custom(move |_| container::Style {
         background: Some(Background::Color(background)),
         border: Border {
+            shape: BorderShape::Continuous,
             radius: motion::radius(12.0).into(),
             ..Default::default()
         },
@@ -287,6 +306,7 @@ impl FereseShell {
             .class(theme::Container::custom(move |_| container::Style {
                 background: Some(Background::Color(well)),
                 border: Border {
+                    shape: BorderShape::Continuous,
                     radius: motion::radius(15.0).into(),
                     ..Default::default()
                 },
@@ -313,6 +333,7 @@ impl FereseShell {
             .class(theme::Container::custom(move |_| container::Style {
                 background: Some(Background::Color(badge_fill.scale_alpha(opacity))),
                 border: Border {
+                    shape: BorderShape::Continuous,
                     radius: motion::radius(8.0).into(),
                     ..Default::default()
                 },
@@ -448,15 +469,10 @@ impl FereseShell {
                     .push(actions);
             }
         }
-        let card = container(face)
-            .id(if history {
-                "ferese-history-card"
-            } else {
-                "ferese-blur-card"
-            })
-            .width(Length::Fill)
-            .clip(true)
-            .class(theme::Container::custom(move |_| container::Style {
+        let card = card_surface(
+            face,
+            history,
+            container::Style {
                 background: if history {
                     Some(Background::Color(Color {
                         a: 0.045 * opacity,
@@ -466,14 +482,16 @@ impl FereseShell {
                     (!compositor_material).then_some(Background::Color(base))
                 },
                 border: Border {
+                    shape: BorderShape::Continuous,
                     color: color_with_opacity(palette.text_muted, 0.18 * opacity),
                     width: if history { 0.0 } else { 1.0 },
                     radius: palette.material_radius.into(),
+                    ..Default::default()
                 },
                 snap: true,
                 ..Default::default()
-            }));
-        let card: Element<'_, cosmic::Action<Message>> = card.into();
+            },
+        );
         let card: Element<'_, cosmic::Action<Message>> = if count > 1 {
             // With translucent materials, complete backing rectangles show
             // through the face and multiply its tint. Paint only the exposed
@@ -488,6 +506,7 @@ impl FereseShell {
                                 ..foreground
                             })),
                             border: Border {
+                                shape: BorderShape::Continuous,
                                 radius: [0.0, 0.0, motion::radius(6.0), motion::radius(6.0)].into(),
                                 ..Default::default()
                             },
@@ -648,6 +667,7 @@ impl FereseShell {
                 .class(theme::Container::custom(move |_| container::Style {
                     background: Some(Background::Color(base)),
                     border: Border {
+                        shape: BorderShape::Continuous,
                         radius: palette.material_radius.into(),
                         ..Default::default()
                     },
@@ -665,6 +685,7 @@ impl FereseShell {
                             .class(theme::Container::custom(move |_| container::Style {
                                 background: Some(Background::Color(well)),
                                 border: Border {
+                                    shape: BorderShape::Continuous,
                                     radius: motion::radius(28.0).into(),
                                     ..Default::default()
                                 },
@@ -766,9 +787,11 @@ impl FereseShell {
                 .class(theme::Container::custom(move |_| container::Style {
                     background: (!compositor_material).then_some(Background::Color(color(palette.surface_popover))),
                     border: Border {
+                        shape: BorderShape::Continuous,
                         color: color_with_opacity(palette.text_muted, 0.18 * opacity),
                         width: 1.0,
                         radius: palette.material_radius.into(),
+                        ..Default::default()
                     },
                     snap: true,
                     ..Default::default()
@@ -803,3 +826,91 @@ impl FereseShell {
         }
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use cosmic::iced::advanced::renderer::{Headless, Renderer as _};
+    use cosmic::iced::advanced::{Layout, layout, mouse, widget::Tree};
+    use cosmic::iced::{Font, Pixels, Rectangle, Size};
+
+    #[test]
+    fn notification_action_hover_stays_inside_card_corners() {
+        check_action_hover("tiny-skia");
+    }
+
+    #[test]
+    #[ignore = "requires a GPU or software Vulkan adapter"]
+    fn gpu_notification_action_hover_stays_inside_card_corners() {
+        check_action_hover("wgpu");
+    }
+
+    fn check_action_hover(backend: &str) {
+        let runtime = tokio::runtime::Builder::new_current_thread()
+            .enable_all()
+            .build()
+            .unwrap();
+        let mut renderer = runtime
+            .block_on(<cosmic::Renderer as Headless>::new(
+                Font::default(),
+                Pixels(14.0),
+                Some(backend),
+            ))
+            .unwrap();
+        let theme = cosmic::Theme::dark();
+        let bounds = Rectangle::with_size(Size::new(368.0, 114.0));
+        for history in [false, true] {
+            for scale in [1.0, 1.25, 1.5] {
+                let action = card_button(
+                    cosmic::widget::Space::new().height(38),
+                    Message::InvokeNotification(1, "action".into()),
+                    Color::WHITE,
+                    Color::WHITE,
+                    false,
+                    "Action".into(),
+                );
+                let face = column([cosmic::widget::Space::new().height(76).into(), action]);
+                let mut card = card_surface(
+                    face,
+                    history,
+                    container::Style {
+                        border: Border {
+                            shape: BorderShape::Continuous,
+                            radius: 14.0.into(),
+                            width: if history { 0.0 } else { 1.0 },
+                            ..Default::default()
+                        },
+                        snap: true,
+                        ..Default::default()
+                    },
+                );
+                let mut tree = Tree::new(card.as_widget());
+                let node =
+                    card.as_widget_mut()
+                        .layout(&mut tree, &renderer, &layout::Limits::new(Size::ZERO, bounds.size()));
+                renderer.reset(bounds);
+                card.as_widget().draw(
+                    &tree,
+                    &mut renderer,
+                    &theme,
+                    &Default::default(),
+                    Layout::new(&node),
+                    mouse::Cursor::Available((80.0, 100.0).into()),
+                    &bounds,
+                );
+                let size = Size::new((bounds.width * scale) as u32, (bounds.height * scale) as u32);
+                let pixels = Headless::screenshot(&mut renderer, size, scale, Color::TRANSPARENT);
+                let alpha = |x: u32, y: u32| pixels[((y * size.width + x) * 4 + 3) as usize];
+                assert_eq!(
+                    alpha(0, size.height - 1),
+                    0,
+                    "{backend}, scale={scale}, history={history}"
+                );
+                assert!(
+                    alpha(size.width / 2, size.height - 4) > 200,
+                    "the action hover must still render"
+                );
+            }
+        }
+    }
+}
diff --git a/shell/ferese-shell/src/status_ui/bar.rs b/shell/ferese-shell/src/status_ui/bar.rs
index 08b3664..f26eed3 100644
--- a/shell/ferese-shell/src/status_ui/bar.rs
+++ b/shell/ferese-shell/src/status_ui/bar.rs
@@ -1,3 +1,4 @@
+use cosmic::iced::border::Shape as BorderShape;
 use cosmic::iced::{Alignment, Background, Border, Rectangle, alignment};
 use cosmic::widget::{button, container, row};
 use cosmic::{Element, theme};
@@ -82,6 +83,7 @@ impl FereseShell {
                     move |_| container::Style {
                         background: Some(Background::Color(foreground)),
                         border: Border {
+                            shape: BorderShape::Continuous,
                             radius: motion::radius(2.0).into(),
                             ..Default::default()
                         },
diff --git a/shell/ferese-shell/src/status_ui/controls.rs b/shell/ferese-shell/src/status_ui/controls.rs
index 97d1370..fdb4e3f 100644
--- a/shell/ferese-shell/src/status_ui/controls.rs
+++ b/shell/ferese-shell/src/status_ui/controls.rs
@@ -1,3 +1,4 @@
+use cosmic::iced::border::Shape as BorderShape;
 use cosmic::iced::{Alignment, Background, Border, Color, Length};
 use cosmic::widget::{button, column, container, row, slider};
 use cosmic::{Element, theme};
@@ -32,6 +33,7 @@ pub(super) fn status_summary<'a>(
                 ..badge_color
             })),
             border: Border {
+                shape: BorderShape::Continuous,
                 radius: motion::radius(16.0).into(),
                 ..Default::default()
             },
@@ -79,6 +81,7 @@ pub(super) fn level_meter(value: u8, foreground: Color, opacity: f32) -> Element
                     }
                 })),
                 border: Border {
+                    shape: BorderShape::Continuous,
                     radius: motion::radius(2.5).into(),
                     ..Default::default()
                 },
diff --git a/shell/ferese-shell/src/status_ui/mod.rs b/shell/ferese-shell/src/status_ui/mod.rs
index 91711f0..8ab006d 100644
--- a/shell/ferese-shell/src/status_ui/mod.rs
+++ b/shell/ferese-shell/src/status_ui/mod.rs
@@ -11,6 +11,7 @@ mod system;
 
 use bar::status_icon;
 use controls::{control_card, menu_button, toggle_row};
+use cosmic::iced::border::Shape as BorderShape;
 use cosmic::widget::column;
 use status::{Action, Snapshot};
 
@@ -242,9 +243,11 @@ impl FereseShell {
                 text_color: Some(primary),
                 icon_color: Some(primary),
                 border: Border {
+                    shape: BorderShape::Continuous,
                     color: color_with_opacity(theme.border, p),
                     width: 1.0,
                     radius: theme.material_radius.into(),
+                    ..Default::default()
                 },
                 snap: true,
                 ..Default::default()
diff --git a/shell/ferese-shell/src/system_modal.rs b/shell/ferese-shell/src/system_modal.rs
index 228b7a3..2168fb9 100644
--- a/shell/ferese-shell/src/system_modal.rs
+++ b/shell/ferese-shell/src/system_modal.rs
@@ -1,3 +1,4 @@
+use cosmic::iced::border::Shape as BorderShape;
 use cosmic::iced::widget::Space;
 use cosmic::widget::column;
 
@@ -620,9 +621,11 @@ impl FereseShell {
                     text_color: Some(palette.text),
                     icon_color: Some(palette.text),
                     border: Border {
+                        shape: BorderShape::Continuous,
                         color: palette.muted.scale_alpha(0.16),
                         width: 1.0,
                         radius: theme.material_radius.into(),
+                        ..Default::default()
                     },
                     snap: true,
                     ..Default::default()