diff --git a/crates/app-iced/src/pages/frame.rs b/crates/app-iced/src/pages/frame.rs
index 91a8a14..817a5d5 100644
--- a/crates/app-iced/src/pages/frame.rs
+++ b/crates/app-iced/src/pages/frame.rs
@@ -39,7 +39,7 @@ mod tests;
 
 pub use pieces::{
     card, divider, empty_state, filled, gap, glyph, glyph_box, scroll_style, text_action,
-    text_role, text_role_centered, text_role_owned, ICON_PX, ICON_SMALL_PX, SCROLLBAR_MARGIN,
+    text_role, text_role_centered, text_role_owned, BASE, ICON_PX, ICON_SMALL_PX, SCROLLBAR_MARGIN,
     SCROLLBAR_WIDTH,
 };
 
diff --git a/crates/app-iced/src/pages/frame/pieces.rs b/crates/app-iced/src/pages/frame/pieces.rs
index e9e1490..817e04c 100644
--- a/crates/app-iced/src/pages/frame/pieces.rs
+++ b/crates/app-iced/src/pages/frame/pieces.rs
@@ -17,6 +17,7 @@ use unlucky_design::shape::ShapeScale;
 use unlucky_design::spacing::Space;
 use unlucky_design::typography::{TypeRole, TypeStyle};
 
+use crate::app::components::interaction::Base;
 use crate::icons;
 use crate::pages::{Action, Message};
 use crate::theme::Ui;
@@ -32,11 +33,29 @@ pub const SCROLLBAR_WIDTH: f32 = 6.0;
 /// 滑块离卡片内边的留白（2px，避免贴边）。
 pub const SCROLLBAR_MARGIN: f32 = 2.0;
 
+/// 描边卡片**真正画出来的底色**（[`card`] 的 `background` 就是它）。
+///
+/// 装配方式与 `components` 的容器同一条纪律（M234）：容器自己画哪个角色，就导出哪个常量，
+/// 里面放的控件用 `.base(BASE)` 把这条信息传下去——两边同源，改色不会漂一半。
+///
+/// 取值不是「反正是 surface」而是**画法本身**：`card()` 画的是 [`MaterialLayer::Card`]
+/// （= `Role::SurfaceContainerLow`，乘面板 α），所以常量也从**同一个** `MaterialLayer` 取角色。
+/// `frame/tests.rs` 有一条断言把「画出来的颜色」与「常量」逐值对上，另有源码结构断言盯着
+/// `card()` 不许改画别的层。
+///
+/// ⚠️ 面板 α < 1（GPU 档的用户设置）时卡片画的是**半透明**合成色，而 [`Base`] 只装得下一个
+/// `Role`：禁用态会按不透明的角色色合成，与卡片实色差一个 α（M234 的 `base.rs` 已登记这条局限）。
+/// CPU 档（`--software-renderer` 验收图）α 恒为 1，两者逐值相同。
+pub const BASE: Base = Base::of(MaterialLayer::Card.surface_role());
+
 /// 描边卡片（长表单容器）。圆角取**规格卡**的 16（`Ui::card_shape`），不是组件表的 12。
 ///
 /// M229 换肤：规格卡 `CARD` 小节把卡片画成 `rx=16`，而 `component_map` 的 `OutlinedCard` 是
 /// `Medium(12)`（官方值）。M228 把这条差异登记为「换肤时取 `inkcat::metrics::CARD`」，这里就是那次取值；
 /// 组件表的值不动（它还服务别的面）。描边仍走 `OutlineVariant` 1px。
+///
+/// M237：卡片里放的禁用 / 可交互控件要接 [`BASE`]（`.base(frame::BASE)`），否则它们会把
+/// 状态层与禁用色叠在画布色上——卡片内的禁用按钮因此看起来「形丢了」（M223 的视觉缺陷）。
 pub fn card<'a>(ui: &'a Ui, content: impl Into<Element<'a, Message>>) -> Element<'a, Message> {
     let shape = ui.card_shape();
     container(content)
@@ -124,6 +143,10 @@ pub fn empty_state<'a>(
 ///
 /// 只画静息、hover、pressed 三态（focus/disabled 归 M75 的 `interaction.rs`）；
 /// 消息是页面自己的 [`Message::Action`]，与 app 的 `Message` 完全解耦。
+///
+/// ⚠️ 状态层按**画布底**合成（`Role::Surface`）：它只服务页头带那一排动作（页头带就是 Canvas 层）。
+/// 放进卡片/面板里必须换成那个容器的 `BASE`——这里没有 `base` 形参，是因为今天零个卡内调用点；
+/// 真要在卡里用它，加一个 `base` 参数而不是在这里猜（M237 登记的接线口径）。
 pub fn text_action<'a>(ui: &'a Ui, label: &'a str, action: Action) -> Element<'a, Message> {
     let spec = Component::TextButton.spec();
     let height = ui.metrics().control_height;
diff --git a/crates/app-iced/src/pages/frame/tests.rs b/crates/app-iced/src/pages/frame/tests.rs
index 38f7fa2..f29ec90 100644
--- a/crates/app-iced/src/pages/frame/tests.rs
+++ b/crates/app-iced/src/pages/frame/tests.rs
@@ -2,11 +2,13 @@
 use super::pieces::{EMPTY_ICON_BLOCK, EMPTY_ICON_GLYPH};
 use super::*;
 
-use unlucky_design::color::SchemeFlavor;
+use unlucky_design::color::{Role, SchemeFlavor};
+use unlucky_design::elevation::MaterialLayer;
 use unlucky_design::shape::ShapeScale;
 use unlucky_design::typography::Platform;
 
-use crate::pages::layout::{frame_metrics, PaneKit};
+use crate::app::components::interaction::Base;
+use crate::pages::layout::{self, frame_metrics, PaneKit};
 use crate::theme::Families;
 
 fn ui() -> Ui {
@@ -147,3 +149,69 @@ fn body_height_subtracts_the_real_shell_chrome() {
     // 窗口比外壳还矮时不返回负数（不许把版面算成 NaN/负值）。
     assert_eq!(body_height(&ui, metrics, 100.0, true), 0.0);
 }
+
+/// **卡片导出的底 = 卡片真正画出来的底色**（M237）。
+///
+/// 抓得住：①`BASE` 被换成「看着像」的角色（`Surface` / `SurfaceContainer` /
+/// `SurfaceContainerHighest` 都能通过「是个容器色」这种含糊的判据）；②`card()` 改画别的材质层
+/// 而常量没跟上（两边漂一半，卡片里的禁用控件又会与卡底脱节）。
+///
+/// 抓不住：面板 α < 1 时的**半透明**合成——`Ui::layer` 会把角色乘 α，而 [`Base`] 只装得下
+/// 一个 `Role`。CPU 验收档 α 恒 1，两者逐值相同；GPU 档的这条差已登记在 `pieces::BASE` 上。
+///
+/// 判据是**页面级像素**（截图量出来的那份，`pages/settings/tests/java_shot.rs`）的前置条件：
+/// 这一条红了，那边的「叠卡片底」就是拿一个错的值在比。
+#[test]
+fn the_card_base_is_the_colour_the_card_actually_paints() {
+    for flavor in [SchemeFlavor::Light, SchemeFlavor::Dark] {
+        let ui = Ui::with_platform(
+            flavor,
+            Platform::Windows,
+            Families {
+                text: "Segoe UI",
+                display: "Segoe UI",
+                mono: "Consolas",
+            },
+        );
+
+        assert_eq!(
+            BASE.role(),
+            MaterialLayer::Card.surface_role(),
+            "{flavor:?}: 卡片底必须是 `card()` 画的那一层的角色"
+        );
+        assert_eq!(
+            ui.layer(MaterialLayer::Card),
+            ui.color(BASE.role()),
+            "{flavor:?}: `card()` 画的颜色与 `BASE` 求出来的不是同一个值"
+        );
+        // 卡片底 ≠ 画布底：相等的话「卡片里的禁用控件叠哪一层」永远看不出区别（判据恒绿）
+        assert_ne!(BASE, Base::CANVAS, "{flavor:?}: 卡片底不能是画布底");
+        assert_ne!(
+            ui.color(BASE.role()),
+            ui.color(Role::Surface),
+            "{flavor:?}: 卡片色与画布色必须可分"
+        );
+    }
+}
+
+/// **源码结构**：`card()` 用 [`MaterialLayer::Card`] 画底，`BASE` 从**同一个**层取角色。
+///
+/// 为什么还要一条扫源码的：iced 的 `Element` 没有内省接口（容器样式是闭包），「画的是哪一层」
+/// 在运行期拿不到；而这件事本身就是契约——容器画什么，就导出什么。换个写法（先存进局部变量）
+/// 会绕过它，那属于重构后要一起改判据的正常代价（与 `pages/tests.rs` 里 `frame::body` 那两条同源）。
+#[test]
+fn the_card_base_and_the_card_paint_share_one_layer() {
+    const PIECES: &str = include_str!("pieces.rs");
+
+    let body = layout::source::function_body(PIECES, "pub fn card<'a>(");
+    assert!(
+        body.contains("ui.layer(MaterialLayer::Card)"),
+        "`frame::card` 的底色必须取 `MaterialLayer::Card`（`BASE` 就是从它推出来的）：\n{body}"
+    );
+
+    let base = layout::source::statement(PIECES, "pub const BASE");
+    assert!(
+        base.contains("Base::of(") && base.contains("MaterialLayer::Card"),
+        "`frame::BASE` 必须从 `card()` 画的那一层取角色：{base}"
+    );
+}
diff --git a/crates/app-iced/src/pages/instances/detail.rs b/crates/app-iced/src/pages/instances/detail.rs
index 817c010..68ef1e4 100644
--- a/crates/app-iced/src/pages/instances/detail.rs
+++ b/crates/app-iced/src/pages/instances/detail.rs
@@ -195,6 +195,10 @@ fn detail_head<'a>(
     .width(Length::Fill);
 
     // 主操作：**全屏唯一**实心 accent（rubric K2）。不可用时退化成禁用态（只清消息，不改身份）。
+    //
+    // M237：这一行**不在卡片里**（详情列直接铺在画布上），所以这两个按钮的底保持
+    // `Base::CANVAS`——把卡底传进来反而会让禁用色叠错层。卡片内的控件（MODS / SAVES /
+    // 启动参数区）各自传 `frame::BASE`，见那几个模块。
     let launch = if detail.can_launch {
         buttons::filled(
             ui,
diff --git a/crates/app-iced/src/pages/instances/launch_args.rs b/crates/app-iced/src/pages/instances/launch_args.rs
index 059f13c..e9d0543 100644
--- a/crates/app-iced/src/pages/instances/launch_args.rs
+++ b/crates/app-iced/src/pages/instances/launch_args.rs
@@ -28,6 +28,7 @@ use crate::app::components::selection::{chip, Chip};
 
 use crate::theme::Ui;
 
+use super::super::frame::BASE;
 use super::super::model::LaunchFacts;
 use super::super::Message as PageMessage;
 use super::state::{LaunchForm, Message};
@@ -120,7 +121,7 @@ fn args_field<'a>(
     on_input: impl Fn(String) -> PageMessage + 'a,
 ) -> Element<'a, PageMessage> {
     column![
-        text_field(ui, Field::new(value).label(label), on_input),
+        text_field(ui, Field::new(value).label(label).base(BASE), on_input),
         super::super::frame::text_role(
             ui,
             TypeRole::BodySmall,
@@ -143,7 +144,7 @@ fn text_field_with_hint<'a>(
     on_input: impl Fn(String) -> PageMessage + 'a,
 ) -> Element<'a, PageMessage> {
     column![
-        text_field(ui, Field::new(value).label(label), on_input),
+        text_field(ui, Field::new(value).label(label).base(BASE), on_input),
         hint,
     ]
     .spacing(ui.space(Space::X1))
@@ -188,7 +189,8 @@ fn backend_row<'a>(
         } else {
             spec.disabled()
         };
-        chips = chips.push(chip(ui, spec));
+        // M237：启动参数区是一张 `frame::card`，chip 的禁用配色（12% 容器 / 38% 内容）叠卡底。
+        chips = chips.push(chip(ui, spec.base(BASE)));
     }
 
     let mut meta = column![
@@ -226,8 +228,14 @@ fn backend_row<'a>(
 
 fn actions_row<'a>(ui: &'a Ui, texts: Texts) -> Element<'a, PageMessage> {
     row![
-        buttons::filled(ui, Button::new(texts.launch_save(), page(Message::Save))),
-        buttons::text(ui, Button::new(texts.launch_reset(), page(Message::Reset))),
+        buttons::filled(
+            ui,
+            Button::new(texts.launch_save(), page(Message::Save)).base(BASE)
+        ),
+        buttons::text(
+            ui,
+            Button::new(texts.launch_reset(), page(Message::Reset)).base(BASE)
+        ),
     ]
     .spacing(ui.space(Space::X2))
     .into()
diff --git a/crates/app-iced/src/pages/instances/mods.rs b/crates/app-iced/src/pages/instances/mods.rs
index d3fd731..815edf7 100644
--- a/crates/app-iced/src/pages/instances/mods.rs
+++ b/crates/app-iced/src/pages/instances/mods.rs
@@ -290,6 +290,9 @@ fn entry_row<'a>(
             }),
         )
     };
+    // M237：开关住在 `frame::card` 里，禁用态的 12% 轨道 / 38% 滑块要叠**卡底**（`frame::BASE`），
+    // 不是画布底——否则「游戏在跑 / 请求在飞」那两档的开关会与卡片底色脱节。
+    let toggle = toggle.base(frame::BASE);
     // 出图取证（`--force-state`）把开关也钉到同一档：否则截图里只有按钮是 hover、
     // 开关还是静息态，视觉复审没法判"悬停时的开关长什么样"。
     let toggle = match forced {
diff --git a/crates/app-iced/src/pages/instances/saves.rs b/crates/app-iced/src/pages/instances/saves.rs
index af1d5ff..0063f09 100644
--- a/crates/app-iced/src/pages/instances/saves.rs
+++ b/crates/app-iced/src/pages/instances/saves.rs
@@ -236,7 +236,9 @@ pub(super) fn section<'a>(
                         Message::Instances(PageMessage::ReloadSaves),
                     ),
                     forced,
-                ),
+                )
+                // M237：卡片里的控件把底传成卡底（hover / 禁用状态层叠卡实色）。
+                .base(frame::BASE),
             ));
         }
         // 旧列表还在时照旧画出来（失败不清列表），用户能看见上一次读到的东西；
@@ -322,7 +324,9 @@ fn head<'a>(
                 Message::Instances(PageMessage::OpenSavesFolder),
             ),
             forced,
-        ),
+        )
+        // M237：这枚按钮在 SAVES 卡里 ⇒ 状态层叠卡底（`frame::BASE`），不是画布底。
+        .base(frame::BASE),
     );
     row![
         container(left)
diff --git a/crates/app-iced/src/pages/logs/diagnostic.rs b/crates/app-iced/src/pages/logs/diagnostic.rs
index ba3143c..f4b755f 100644
--- a/crates/app-iced/src/pages/logs/diagnostic.rs
+++ b/crates/app-iced/src/pages/logs/diagnostic.rs
@@ -169,10 +169,12 @@ fn summary_block<'a>(ui: &'a Ui, catalog: &Catalog, logs: &Logs) -> Element<'a,
             iced::widget::Space::new().width(Length::Fill),
             buttons::text(
                 ui,
+                // M237：页脚按钮在诊断卡（`panel::card`）里 ⇒ 状态层叠卡底，不是画布底。
                 Button::new(
                     catalog.text(Key::LogsCopySummary),
                     Message::CopySummary(logs.summary()),
-                ),
+                )
+                .base(panel::BASE),
             ),
         ]
         .width(Length::Fill)
diff --git a/crates/app-iced/src/pages/logs/panel.rs b/crates/app-iced/src/pages/logs/panel.rs
index cab5e8b..a25ff8e 100644
--- a/crates/app-iced/src/pages/logs/panel.rs
+++ b/crates/app-iced/src/pages/logs/panel.rs
@@ -20,11 +20,19 @@ use iced::{Background, Element, Length};
 
 use unlucky_design::elevation::MaterialLayer;
 
+use crate::app::components::interaction::Base;
 use crate::theme::Ui;
 
 use super::super::frame;
 use super::super::Message;
 
+/// 本卡的底：**与 [`frame::BASE`] 是同一个常量**（两张卡画的是同一个 `Card` 材质层，只是
+/// 一张按内容撑高、一张定高）。
+///
+/// 卡片里的控件（`Copy summary` 这类 Text 按钮）要用 `.base(BASE)`：它们的 hover / 禁用状态层
+/// 都得叠在卡片实色上，不是画布上。
+pub const BASE: Base = frame::BASE;
+
 /// 定高卡片（`Card` 材质层 + `OutlinedCard` 形状与 **1px 描边**，与 `frame::card` 同一套令牌：
 /// 实例页 / 下载页的卡都带这条描边，日志页的两张主卡不能例外）。
 pub fn card<'a>(
diff --git a/crates/app-iced/src/pages/settings/general.rs b/crates/app-iced/src/pages/settings/general.rs
index c44b083..4842889 100644
--- a/crates/app-iced/src/pages/settings/general.rs
+++ b/crates/app-iced/src/pages/settings/general.rs
@@ -335,10 +335,11 @@ fn chip<'a>(ui: &'a Ui, text: &'a str, selected: bool, choice: LangChoice) -> El
         let background = if selected {
             Some(Background::Color(ui.color(Role::SecondaryContainer)))
         } else if matches!(status, button::Status::Hovered | button::Status::Pressed) {
+            // M237：这一组整个住在 `frame::card` 里，状态层叠**卡底**（不是画布）。
             Some(Background::Color(ui.state_over(
                 StateLayer::Hover,
                 Role::OnSurface,
-                Role::Surface,
+                frame::BASE.role(),
             )))
         } else {
             None
diff --git a/crates/app-iced/src/pages/settings/general/theme.rs b/crates/app-iced/src/pages/settings/general/theme.rs
index 4e80676..8c4e6f6 100644
--- a/crates/app-iced/src/pages/settings/general/theme.rs
+++ b/crates/app-iced/src/pages/settings/general/theme.rs
@@ -120,10 +120,11 @@ fn chip<'a>(ui: &'a Ui, text: &'a str, selected: bool, mode: ThemeMode) -> Eleme
         let background = if selected {
             Some(Background::Color(ui.color(Role::SecondaryContainer)))
         } else if matches!(status, button::Status::Hovered | button::Status::Pressed) {
+            // M237：主题三档同样住在设置卡里，状态层叠卡底（`frame::BASE`）。
             Some(Background::Color(ui.state_over(
                 StateLayer::Hover,
                 Role::OnSurface,
-                Role::Surface,
+                frame::BASE.role(),
             )))
         } else {
             None
diff --git a/crates/app-iced/src/pages/settings/java/download_view.rs b/crates/app-iced/src/pages/settings/java/download_view.rs
index 1a5f76b..f63f5d8 100644
--- a/crates/app-iced/src/pages/settings/java/download_view.rs
+++ b/crates/app-iced/src/pages/settings/java/download_view.rs
@@ -26,7 +26,7 @@ use unlucky_design::typography::TypeRole;
 use unlucky_i18n::{Catalog, Key};
 
 use crate::app::components::selection::{chip, Chip};
-use crate::pages::frame::{divider, text_role_owned};
+use crate::pages::frame::{divider, text_role_owned, BASE};
 use crate::pages::Message;
 use crate::theme::Ui;
 
@@ -122,22 +122,24 @@ fn choice_row<'a>(
 ) -> Element<'a, Message> {
     let title = format!("Java {}", choice.major);
     let mut badges = row![].spacing(ui.space(Space::X1));
+    // M237：徽标是**禁用配色**（`Chip::badge` = 12% 容器 / 38% 内容），而这个板块整个住在
+    // `frame::card` 里 ⇒ 底必须是卡底，否则徽标会把禁用色叠在画布色上。
     if choice.lts {
         badges = badges.push(chip(
             ui,
-            Chip::badge(catalog.text(Key::SettingsJavaDownloadLts)),
+            Chip::badge(catalog.text(Key::SettingsJavaDownloadLts)).base(BASE),
         ));
     }
     if choice.baseline {
         badges = badges.push(chip(
             ui,
-            Chip::badge(catalog.text(Key::SettingsJavaDownloadBaseline)),
+            Chip::badge(catalog.text(Key::SettingsJavaDownloadBaseline)).base(BASE),
         ));
     }
     if recommended {
         badges = badges.push(chip(
             ui,
-            Chip::badge(catalog.text(Key::SettingsJavaDownloadRecommended)),
+            Chip::badge(catalog.text(Key::SettingsJavaDownloadRecommended)).base(BASE),
         ));
     }
 
@@ -256,11 +258,12 @@ fn install_button<'a>(
         Key::SettingsJavaDownloadAction
     });
     if busy {
-        return chip(ui, Chip::badge(label));
+        // 忙时那枚「下载」是**禁用配色**的徽标（不是可点 chip），同样叠在卡底上（M237）。
+        return chip(ui, Chip::badge(label).base(BASE));
     }
     chip(
         ui,
-        Chip::filter(label, false, msg(JavaMessage::Download(major))),
+        Chip::filter(label, false, msg(JavaMessage::Download(major))).base(BASE),
     )
 }
 
diff --git a/crates/app-iced/src/pages/settings/java/fields.rs b/crates/app-iced/src/pages/settings/java/fields.rs
index dc4ac00..87676ed 100644
--- a/crates/app-iced/src/pages/settings/java/fields.rs
+++ b/crates/app-iced/src/pages/settings/java/fields.rs
@@ -14,7 +14,7 @@ use unlucky_i18n::{Catalog, Key};
 
 use crate::app::components::buttons::{self, Button};
 use crate::app::components::inputs::{text_field, Field, FieldVariant};
-use crate::pages::frame::text_role_owned;
+use crate::pages::frame::{text_role_owned, BASE};
 use crate::pages::Message;
 use crate::theme::Ui;
 
@@ -23,16 +23,19 @@ use super::view::msg;
 use super::Message as JavaMessage;
 
 /// 手动添加一行：输入框 + 「添加」按钮 + 原因。
+///
+/// M237：这一行住在 `frame::card` 里，输入框与按钮都把底传成 `frame::BASE`（禁用/状态层叠卡底）。
 pub(super) fn add_row<'a>(ui: &'a Ui, catalog: Catalog, state: &'a State) -> Element<'a, Message> {
     let field = Field::new(&state.add_draft)
         .variant(FieldVariant::Outlined)
         .label(catalog.text(Key::SettingsJavaAdd))
         .placeholder(catalog.text(Key::SettingsJavaAddPlaceholder))
-        .supporting(catalog.text(Key::SettingsJavaAddHint));
+        .supporting(catalog.text(Key::SettingsJavaAddHint))
+        .base(BASE);
     let add = if state.add_draft.trim().is_empty() || !state.storage {
         buttons::outlined(
             ui,
-            Button::disabled(catalog.text(Key::SettingsJavaAddAction)),
+            Button::disabled(catalog.text(Key::SettingsJavaAddAction)).base(BASE),
         )
     } else {
         buttons::outlined(
@@ -40,7 +43,8 @@ pub(super) fn add_row<'a>(ui: &'a Ui, catalog: Catalog, state: &'a State) -> Ele
             Button::new(
                 catalog.text(Key::SettingsJavaAddAction),
                 msg(JavaMessage::Add),
-            ),
+            )
+            .base(BASE),
         )
     };
     row![
@@ -71,7 +75,8 @@ pub(super) fn memory_field<'a>(
     );
     let field = Field::new(&state.memory)
         .variant(FieldVariant::Outlined)
-        .label(catalog.text(Key::SettingsJavaMemory));
+        .label(catalog.text(Key::SettingsJavaMemory))
+        .base(BASE);
     // 校验不过就把输入框本身标红（不只是下面那行字）：用户一眼看到「是这个框有问题」。
     let field = match state.validate() {
         Err(Refusal::MemoryEmpty | Refusal::MemoryNotNumber | Refusal::MemoryRange) => {
@@ -124,7 +129,8 @@ pub(super) fn jvm_field<'a>(
         .variant(FieldVariant::Outlined)
         .label(catalog.text(Key::SettingsJavaJvm))
         .placeholder(catalog.text(Key::SettingsJavaJvmPlaceholder))
-        .supporting(catalog.text(Key::SettingsJavaJvmHint));
+        .supporting(catalog.text(Key::SettingsJavaJvmHint))
+        .base(BASE);
     // 两种拒绝都长在这个框上：引号没配对、或者粘了超过 1024 字符的一整段（M199）。
     let field = if matches!(
         state.validate(),
@@ -165,9 +171,9 @@ pub(super) fn actions_row<'a>(
 ) -> Element<'a, Message> {
     let label = catalog.text(Key::SettingsJavaSave);
     if state.can_save() {
-        buttons::filled(ui, Button::new(label, msg(JavaMessage::Save)))
+        buttons::filled(ui, Button::new(label, msg(JavaMessage::Save)).base(BASE))
     } else {
-        buttons::filled(ui, Button::disabled(label))
+        buttons::filled(ui, Button::disabled(label).base(BASE))
     }
 }
 
diff --git a/crates/app-iced/src/pages/settings/java/prefs_view.rs b/crates/app-iced/src/pages/settings/java/prefs_view.rs
index 108552c..ff889c5 100644
--- a/crates/app-iced/src/pages/settings/java/prefs_view.rs
+++ b/crates/app-iced/src/pages/settings/java/prefs_view.rs
@@ -23,7 +23,7 @@ use unlucky_i18n::{Catalog, Key};
 use crate::app::components::buttons::{self, Button};
 use crate::app::components::inputs::{text_field, Field, FieldVariant};
 use crate::app::components::selection::{chip, Chip};
-use crate::pages::frame::{divider, text_role_owned};
+use crate::pages::frame::{divider, text_role_owned, BASE};
 use crate::pages::Message;
 use crate::theme::Ui;
 
@@ -52,7 +52,8 @@ fn install_root<'a>(ui: &'a Ui, catalog: Catalog, state: &'a State) -> Element<'
         .variant(FieldVariant::Outlined)
         .label(catalog.text(Key::SettingsJavaInstallRoot))
         .placeholder(catalog.text(Key::SettingsJavaInstallRootPlaceholder))
-        .supporting(catalog.text(Key::SettingsJavaInstallRootHint));
+        .supporting(catalog.text(Key::SettingsJavaInstallRootHint))
+        .base(BASE);
     let field = if prefs.validate().is_err() {
         field.error()
     } else {
@@ -184,7 +185,8 @@ fn vendor_order<'a>(ui: &'a Ui, catalog: Catalog, state: &'a State) -> Element<'
             Button::new(
                 catalog.text(Key::SettingsJavaVendorReset),
                 msg(JavaMessage::ResetPriority),
-            ),
+            )
+            .base(BASE),
         ));
     }
     list.into()
@@ -215,7 +217,8 @@ fn vendor_row<'a>(
             catalog.text(Key::SettingsJavaVendorUp),
             false,
             msg(JavaMessage::MoveVendor { index, up: true }),
-        ),
+        )
+        .base(BASE),
     );
     let down = chip(
         ui,
@@ -223,7 +226,8 @@ fn vendor_row<'a>(
             catalog.text(Key::SettingsJavaVendorDown),
             false,
             msg(JavaMessage::MoveVendor { index, up: false }),
-        ),
+        )
+        .base(BASE),
     );
     row![
         container(
@@ -266,7 +270,8 @@ fn auto_install<'a>(ui: &'a Ui, catalog: Catalog, state: &'a State) -> Element<'
                 catalog.text(Key::SettingsJavaAutoInstallOn),
                 on,
                 msg(JavaMessage::ToggleAutoInstall(true)),
-            ),
+            )
+            .base(BASE),
         ),
         chip(
             ui,
@@ -274,7 +279,8 @@ fn auto_install<'a>(ui: &'a Ui, catalog: Catalog, state: &'a State) -> Element<'
                 catalog.text(Key::SettingsJavaAutoInstallOff),
                 !on,
                 msg(JavaMessage::ToggleAutoInstall(false)),
-            ),
+            )
+            .base(BASE),
         ),
     ]
     .spacing(ui.space(Space::X1));
@@ -304,9 +310,12 @@ fn auto_install<'a>(ui: &'a Ui, catalog: Catalog, state: &'a State) -> Element<'
 fn actions<'a>(ui: &'a Ui, catalog: Catalog, state: &'a State) -> Element<'a, Message> {
     let label = catalog.text(Key::SettingsJavaPrefsSave);
     let save = if state.prefs.dirty() && state.storage {
-        buttons::filled(ui, Button::new(label, msg(JavaMessage::SavePrefs)))
+        buttons::filled(
+            ui,
+            Button::new(label, msg(JavaMessage::SavePrefs)).base(BASE),
+        )
     } else {
-        buttons::filled(ui, Button::disabled(label))
+        buttons::filled(ui, Button::disabled(label).base(BASE))
     };
     let hint = if state.prefs.dirty() {
         catalog.text(Key::SettingsJavaPrefsUnsaved).to_string()
diff --git a/crates/app-iced/src/pages/settings/java/view.rs b/crates/app-iced/src/pages/settings/java/view.rs
index 612912e..25b445f 100644
--- a/crates/app-iced/src/pages/settings/java/view.rs
+++ b/crates/app-iced/src/pages/settings/java/view.rs
@@ -25,7 +25,7 @@ use unlucky_i18n::{Catalog, Key, Lang};
 
 use crate::app::components::buttons::{self, Button};
 use crate::app::components::selection::{chip, Chip};
-use crate::pages::frame::{card, divider, text_role_owned};
+use crate::pages::frame::{card, divider, text_role_owned, BASE};
 use crate::pages::Message;
 use crate::theme::Ui;
 
@@ -114,10 +114,15 @@ fn status_row<'a>(ui: &'a Ui, catalog: Catalog, state: &State) -> Element<'a, Me
     };
 
     let scan_label = catalog.text(Key::SettingsJavaScan);
+    // M237：这一整张卡片是 `frame::card` 画的（`Role::SurfaceContainerLow`），所以卡片里的
+    // 控件把底传成 `frame::BASE`——禁用态的 10% / 12% 叠在卡底上，不是画布上。
     let scan = if scanning || !state.storage {
-        buttons::filled(ui, Button::disabled(scan_label))
+        buttons::filled(ui, Button::disabled(scan_label).base(BASE))
     } else {
-        buttons::filled(ui, Button::new(scan_label, msg(JavaMessage::Scan)))
+        buttons::filled(
+            ui,
+            Button::new(scan_label, msg(JavaMessage::Scan)).base(BASE),
+        )
     };
     // 已经按过取消（线程还没退出）时，「取消」也灰掉：再按一次没有任何意义。
     let cancel = buttons::tonal(
@@ -129,7 +134,8 @@ fn status_row<'a>(ui: &'a Ui, catalog: Catalog, state: &State) -> Element<'a, Me
             )
         } else {
             Button::disabled(catalog.text(Key::SettingsJavaCancel))
-        },
+        }
+        .base(BASE),
     );
 
     // 「扫描已取消」那句只在线程**真退出之后**出现；退出之前状态行本身写着「正在取消…」。
@@ -227,7 +233,7 @@ fn runtime_row<'a>(
         None => (String::new(), ui.color(Role::OnSurfaceVariant)),
     };
 
-    let action = chip(ui, action_chip(catalog, state, runtime));
+    let action = chip(ui, action_chip(catalog, state, runtime).base(BASE));
 
     let mut block = column![row![
         container(
diff --git a/crates/app-iced/src/pages/settings/logs_row.rs b/crates/app-iced/src/pages/settings/logs_row.rs
index a2eef3e..b543034 100644
--- a/crates/app-iced/src/pages/settings/logs_row.rs
+++ b/crates/app-iced/src/pages/settings/logs_row.rs
@@ -105,7 +105,12 @@ fn action_button<'a>(ui: &'a Ui, label: &'a str, message: Message) -> Element<'a
     .style(move |_theme: &IcedTheme, status| {
         let background =
             matches!(status, button::Status::Hovered | button::Status::Pressed).then(|| {
-                Background::Color(ui.state_over(StateLayer::Hover, Role::OnSurface, Role::Surface))
+                // M237：这一行住在设置卡里（`frame::card`），hover 状态层叠卡底。
+                Background::Color(ui.state_over(
+                    StateLayer::Hover,
+                    Role::OnSurface,
+                    frame::BASE.role(),
+                ))
             });
         button::Style {
             background,
diff --git a/crates/app-iced/src/pages/settings/tests/java_shot.rs b/crates/app-iced/src/pages/settings/tests/java_shot.rs
new file mode 100644
index 0000000..3749060
--- /dev/null
+++ b/crates/app-iced/src/pages/settings/tests/java_shot.rs
@@ -0,0 +1,206 @@
+//! 「Java」卡片里的**禁用控件叠的是卡底**——页面级**像素**判据（M237）。
+//!
+//! ## 为什么非要从页面量
+//!
+//! `interaction::disabled::tests` 能证明「`Base` 传对了，合成就是对的」，`buttons::tests::base`
+//! 能证明「`Button::base` 接到了样式闭包」——两条都**不**证明页面那天真的把 `frame::BASE` 传下去了
+//! （M229 的教训：参数在、语义在，8 个调用点全传死 `Role::Surface`）。只有页面自己的像素能证明
+//! 「这一屏里的禁用按钮是叠在卡底上画的」。
+//!
+//! ## 量什么
+//!
+//! `ULL_JAVA_STATE=scanning` 那一格里有一颗**禁用**的 Filled 按钮（「立即扫描」；「保存」同样是
+//! 禁用态，但在这张卡的下半段、1180×760 的一帧里落在折叠线以下，量不到），
+//! 它住在 `frame::card` 里（卡底 = `MaterialLayer::Card` = `SurfaceContainerLow`）。
+//! 禁用容器 = `OnSurface` @10% 叠在底上，于是「叠卡底」与「叠画布」是**两个不同的逐位值**
+//! （实测的 8 位 RGB，十进制写在这里——色值十六进制字面量在源码里是禁的，见
+//! `tests/no_hardcoded_tokens.rs`）：
+//!
+//! | 板 | 叠画布（`Base::CANVAS`） | 叠卡底（`frame::BASE`） | 逐位差 |
+//! |---|---|---|---|
+//! | Silver（浅） | (226, 226, 227) | (221, 221, 222) | 5/255 |
+//! | Ink（深） | (37, 43, 36) | (40, 45, 40) | 3/255 |
+//!
+//! 差得这么小正是**必须逐位匹配**的理由：肉眼（以及 `±10` 容差的扫描器）分不出这两档，
+//! 而「叠错层」这件事本身是确定的。两个值都在测试里**现算**
+//! （`interaction::disabled_button_colors`），不写死——换板 / 改令牌时判据跟着走；
+//! 上表只是给人读的量测记录。
+//!
+//! ## 跑法（1180×760 @1.0，`--software-renderer`）
+//!
+//! ```text
+//! EXE=${CARGO_TARGET_DIR:-target}/debug/unlucky-launcher-iced
+//! OUT=${CARGO_TARGET_DIR:-target}/m237 && mkdir -p "$OUT"
+//!
+//! ULL_START_ROUTE=settings ULL_SETTINGS_GROUP=2 ULL_JAVA_STATE=scanning \
+//!   $EXE --software-renderer --scale-factor=1 \
+//!   --screenshot "$OUT/java-light.png" --screenshot-theme=light
+//! ULL_M237_JAVA_SHOT="$OUT/java-light.png" cargo test -p unlucky-app-iced java_shot
+//! ```
+//!
+//! `ULL_SETTINGS_GROUP=2` 是「Java」组（`settings::java::JAVA_GROUP`）；不给就画出 General 组，
+//! 那张图上没有禁用填充按钮，判据会拿不到样本并**大声报出来**（不是静默通过）。
+//!
+//! ## 抓得住 / 抓不住
+//!
+//! - 抓得住：① 页面调用点漏了 `.base(..)`（回落到 `Base::CANVAS`）——卡区里会出现「叠画布」档、
+//!   「叠卡底」档消失；② `frame::BASE` 被改成别的角色（判据跟着 `BASE` 走，于是与像素对不上）；
+//!   ③ 出图通道换了组 / 换了主题（判据先用卡底色**认出**板，认不出就红）。
+//! - 抓不住：① 面板 α < 1 的 GPU 档（本判据读的是 tiny-skia 的图，α 恒 1）；② 卡外的控件
+//!   （判据只看卡区）；③ 具体是哪一颗按钮变成了卡底（只数颜色总量，不定位控件）。
+
+use unlucky_design::color::SchemeFlavor;
+use unlucky_design::typography::Platform;
+
+use crate::app::components::interaction::{self, Base};
+use crate::pages::frame;
+use crate::theme::{Families, Ui};
+
+const FAMILIES: Families = Families {
+    text: "Segoe UI",
+    display: "Segoe UI",
+    mono: "Consolas",
+};
+
+/// 出图路径（判据的输入）。
+const SHOT_ENV: &str = "ULL_M237_JAVA_SHOT";
+/// 卡区里「叠卡底」的禁用容器像素下限（两颗 40 高的药丸，扣掉字形与圆角后实测 ≈3100）。
+const MIN_HITS: usize = 1000;
+/// 「正确档 : 错误档」的最小倍数（抗锯齿会在边缘撞上另一档的精确值，实测个位到十几像素）。
+const STRAY_RATIO: usize = 10;
+/// 卡区的下限（一张 400+ 宽的卡，实测 ≈32 万像素）——低于它说明这一屏根本没有卡。
+const MIN_CARD_PX: usize = 50_000;
+
+fn ui(flavor: SchemeFlavor) -> Ui {
+    Ui::with_platform(flavor, Platform::Windows, FAMILIES)
+}
+
+/// iced 颜色 → 8 位三元组（与 `to_iced` 同一条口径：`f32` 0..1 四舍五入回 0..255）。
+fn rgb(color: iced::Color) -> [u8; 3] {
+    let byte = |channel: f32| (channel * 255.0).round().clamp(0.0, 255.0) as u8;
+    [byte(color.r), byte(color.g), byte(color.b)]
+}
+
+/// 一张 RGB 图（只留本判据要的两件事：尺寸 + 取点）。
+struct Shot {
+    width: usize,
+    height: usize,
+    pixels: Vec<[u8; 3]>,
+}
+
+impl Shot {
+    fn load(path: &std::path::Path) -> Self {
+        let bytes = std::fs::read(path).expect("读截图");
+        let image = image::load_from_memory(&bytes).expect("解 PNG").to_rgb8();
+        let (width, height) = (image.width() as usize, image.height() as usize);
+        Self {
+            width,
+            height,
+            pixels: image.pixels().map(|pixel| pixel.0).collect(),
+        }
+    }
+
+    fn at(&self, x: usize, y: usize) -> [u8; 3] {
+        self.pixels[y * self.width + x]
+    }
+
+    /// 逐位相等的像素数（`±10` 容差在这里没用：两档底只差 5 个 RGB 单位）。
+    fn count(&self, color: [u8; 3]) -> usize {
+        self.pixels.iter().filter(|pixel| **pixel == color).count()
+    }
+
+    /// 某颜色像素的外接矩形 `(x0, y0, x1, y1)`（闭区间），一个都没有时 `None`。
+    fn bbox(&self, color: [u8; 3]) -> Option<(usize, usize, usize, usize)> {
+        let mut found = None;
+        for y in 0..self.height {
+            for x in 0..self.width {
+                if self.at(x, y) == color {
+                    let (x0, y0, x1, y1) = found.unwrap_or((x, y, x, y));
+                    found = Some((x0.min(x), y0.min(y), x1.max(x), y1.max(y)));
+                }
+            }
+        }
+        found
+    }
+
+    /// 矩形内的逐位相等像素数。
+    fn count_in(&self, color: [u8; 3], rect: (usize, usize, usize, usize)) -> usize {
+        let (x0, y0, x1, y1) = rect;
+        (y0..=y1.min(self.height - 1))
+            .map(|y| {
+                (x0..=x1.min(self.width - 1))
+                    .filter(|x| self.at(*x, y) == color)
+                    .count()
+            })
+            .sum()
+    }
+}
+
+/// 按**卡底色**认出这张图是哪块板（认不出 = 这一屏没有卡 / 主题对不上，直接红）。
+fn flavor_of(shot: &Shot) -> SchemeFlavor {
+    let mut candidates = Vec::new();
+    for flavor in [SchemeFlavor::Light, SchemeFlavor::Dark] {
+        let card = rgb(ui(flavor).color(frame::BASE.role()));
+        let hits = shot.count(card);
+        if hits >= MIN_CARD_PX {
+            candidates.push((flavor, card, hits));
+        }
+    }
+    assert_eq!(
+        candidates.len(),
+        1,
+        "这一屏里「卡底」色的像素必须恰好落在一种板上，实测 {candidates:?}：\
+         检查出图命令是否带了 `--screenshot-theme` 与 `ULL_SETTINGS_GROUP=2`"
+    );
+    candidates[0].0
+}
+
+#[test]
+fn the_java_card_composites_disabled_controls_over_its_own_base() {
+    let Some(path) = std::env::var_os(SHOT_ENV) else {
+        // 本机允许不喂图（会大声说一句）；CI 里没图就是失败——判据静默空转等于没有判据。
+        assert!(
+            std::env::var_os("CI").is_none(),
+            "守门未喂图：{SHOT_ENV} 没设（跑法见 `java_shot.rs` 的模块文档）"
+        );
+        eprintln!("[skip] {SHOT_ENV} 没设：页面级像素判据未执行（本机档）");
+        return;
+    };
+
+    let shot = Shot::load(std::path::Path::new(&path));
+    let flavor = flavor_of(&shot);
+    let ui = ui(flavor);
+
+    let over_card = rgb(interaction::disabled_button_colors(&ui, frame::BASE).0);
+    let over_canvas = rgb(interaction::disabled_button_colors(&ui, Base::CANVAS).0);
+    assert_ne!(
+        over_card, over_canvas,
+        "{flavor:?}: 叠卡底与叠画布的禁用容器算出来一样 —— 判据自己立不住"
+    );
+
+    // 卡区 = 卡底色像素的外接矩形（卡是这一屏最大的同色块）
+    let card_color = rgb(ui.color(frame::BASE.role()));
+    let rect = shot
+        .bbox(card_color)
+        .unwrap_or_else(|| panic!("{flavor:?}: 图里找不到卡底色 {card_color:?}"));
+
+    let hits = shot.count_in(over_card, rect);
+    let stray = shot.count_in(over_canvas, rect);
+
+    eprintln!(
+        "[pages] OK flavor={flavor:?} 卡区 {rect:?}：叠卡底 {over_card:?} {hits} px · \
+         叠画布 {over_canvas:?} {stray} px"
+    );
+
+    assert!(
+        hits >= MIN_HITS,
+        "{flavor:?}: 卡区里「叠 {:?}」的禁用容器只有 {hits} px（应 ≥{MIN_HITS}）—— \
+         卡片里的禁用控件没把 `frame::BASE` 传下去（还在按画布合成）",
+        frame::BASE.role()
+    );
+    assert!(
+        hits > stray * STRAY_RATIO,
+        "{flavor:?}: 卡区里「叠卡底」{hits} px，而「叠画布」{stray} px（要求前者 ≥ 后者 ×{STRAY_RATIO}）—— \
+         卡区里仍有一部分禁用控件按 `Role::Surface` 合成"
+    );
+}
diff --git a/crates/app-iced/src/pages/settings/tests/mod.rs b/crates/app-iced/src/pages/settings/tests/mod.rs
index f9a9260..097d7ed 100644
--- a/crates/app-iced/src/pages/settings/tests/mod.rs
+++ b/crates/app-iced/src/pages/settings/tests/mod.rs
@@ -40,6 +40,7 @@ mod appearance_section;
 mod download_section;
 mod general_section;
 mod java_section;
+mod java_shot;
 mod scroll_fit;
 mod update_section;
 
diff --git a/crates/app-iced/src/pages/tests.rs b/crates/app-iced/src/pages/tests.rs
index ee065e5..a9f2a11 100644
--- a/crates/app-iced/src/pages/tests.rs
+++ b/crates/app-iced/src/pages/tests.rs
@@ -2,6 +2,8 @@
 //!
 //! 每条断言都注明了「抓得住什么 / 抓不住什么」——只测到纯函数，渲染真像素另见报告里的图与量测。
 
+mod base_wiring;
+
 use super::layout::{self, frame_metrics, measure_cap_px, PaneKit, WidthClass};
 use super::nav::NAV;
 use super::*;
diff --git a/crates/app-iced/src/pages/tests/base_wiring.rs b/crates/app-iced/src/pages/tests/base_wiring.rs
new file mode 100644
index 0000000..5b79859
--- /dev/null
+++ b/crates/app-iced/src/pages/tests/base_wiring.rs
@@ -0,0 +1,116 @@
+//! 页面层**接线**守门：卡片里的控件有没有把 `frame::BASE` 传下去（M237）。
+//!
+//! ## 为什么还要一条「数接线点」的判据
+//!
+//! 像素判据（`pages/settings/tests/java_shot.rs`）只落在**一屏能拍到的**控件上。实例详情页的
+//! MODS / SAVES 两张卡在现有夹具下拍不到禁用控件：`ULL_MODS_FIXTURE` 把 `running` 写死成
+//! `false`（开关全是启用态），SAVES 的动作行在 1180×760 的折叠线以下。那几处接线于是**没有
+//! 任何渲染证据**能守——有人删掉一个 `.base(..)`，图和一整张像素判据都不会变。
+//!
+//! 这里退一步，只数「每个文件里出现了几次接线调用」。它证明的是**接线还在**，不是「画对了」；
+//! 真正的「叠的是哪一层底」由像素判据与 `interaction::disabled::tests` 两层负责。
+//!
+//! ## 抓得住 / 抓不住
+//!
+//! - 抓得住：删掉 / 注释掉某个调用点的 `.base(..)`、或把整个文件的接线回退（数字掉一即红）。
+//! - 抓不住：① 传**错的**底（换成 `Base::CANVAS` 数字不变，只有像素判据能抓）；
+//!   ② 把接线搬进辅助函数（那是等价重构，改这里的数字并在提交信息里说明搬去了哪）；
+//!   ③ 新加的控件（新调用点没人接线时数字不会变——这条只守**已经签过的**那几处）。
+//!
+//! ## 数字怎么来的
+//!
+//! 每个文件里 `.base(` 的出现次数（`grep -o "\.base(" <file> | wc -l`），三个手写样式的文件
+//! 数是 `BASE.role()`（它们不走组件的 `.base(..)`，而是把状态层直接叠在 `frame::BASE` 上）。
+
+/// `(文件, 期望的接线次数)`：文件路径相对 `pages/`。
+const WIRED: [(&str, usize); 8] = [
+    ("instances/mods.rs", 1),
+    ("instances/saves.rs", 2),
+    ("instances/launch_args.rs", 5),
+    ("logs/diagnostic.rs", 1),
+    ("settings/java/view.rs", 4),
+    ("settings/java/fields.rs", 7),
+    ("settings/java/prefs_view.rs", 8),
+    ("settings/java/download_view.rs", 5),
+];
+
+/// 手写样式（不走组件 `.base(..)`）的三处：状态层直接叠在 `frame::BASE.role()` 上。
+const ROLE_SITES: [(&str, usize); 3] = [
+    ("settings/general.rs", 1),
+    ("settings/general/theme.rs", 1),
+    ("settings/logs_row.rs", 1),
+];
+
+fn count(haystack: &str, needle: &str) -> usize {
+    haystack.matches(needle).count()
+}
+
+#[test]
+fn every_card_internal_control_site_still_passes_a_base() {
+    let sources: [(&str, &str); 11] = [
+        ("instances/mods.rs", include_str!("../instances/mods.rs")),
+        ("instances/saves.rs", include_str!("../instances/saves.rs")),
+        (
+            "instances/launch_args.rs",
+            include_str!("../instances/launch_args.rs"),
+        ),
+        ("logs/diagnostic.rs", include_str!("../logs/diagnostic.rs")),
+        (
+            "settings/java/view.rs",
+            include_str!("../settings/java/view.rs"),
+        ),
+        (
+            "settings/java/fields.rs",
+            include_str!("../settings/java/fields.rs"),
+        ),
+        (
+            "settings/java/prefs_view.rs",
+            include_str!("../settings/java/prefs_view.rs"),
+        ),
+        (
+            "settings/java/download_view.rs",
+            include_str!("../settings/java/download_view.rs"),
+        ),
+        (
+            "settings/general.rs",
+            include_str!("../settings/general.rs"),
+        ),
+        (
+            "settings/general/theme.rs",
+            include_str!("../settings/general/theme.rs"),
+        ),
+        (
+            "settings/logs_row.rs",
+            include_str!("../settings/logs_row.rs"),
+        ),
+    ];
+
+    for (name, want) in WIRED {
+        let source = sources
+            .iter()
+            .find(|(file, _)| *file == name)
+            .map(|(_, source)| *source)
+            .unwrap_or_else(|| panic!("{name} 不在本判据的清单里（清单与文件对不上）"));
+        let got = count(source, ".base(");
+        assert_eq!(
+            got, want,
+            "{name}: `.base(..)` 出现 {got} 次，期望 {want} 次 —— 卡片内的控件必须把 \
+             `frame::BASE` 传下去（`pages/frame/pieces.rs` 的 `BASE`）。\
+             如果你是把接线搬进了辅助函数（等价重构），把这里的数字跟着改并说明搬去了哪。"
+        );
+    }
+
+    for (name, want) in ROLE_SITES {
+        let source = sources
+            .iter()
+            .find(|(file, _)| *file == name)
+            .map(|(_, source)| *source)
+            .unwrap_or_else(|| panic!("{name} 不在本判据的清单里（清单与文件对不上）"));
+        let got = count(source, "BASE.role()");
+        assert_eq!(
+            got, want,
+            "{name}: `BASE.role()` 出现 {got} 次，期望 {want} 次 —— 手写按钮的 hover / 禁用\
+             状态层必须叠在卡片底上（画布底会让它在卡里偏色，M237）"
+        );
+    }
+}