refactor: remove exact nested css duplicates

app/config/architecture-inventory.json

@@ -309,13 +309,13 @@
   "code_hotspots": [
     {
       "path": "frontend/styles/styles.css",
-      "bytes": 361501,
+      "bytes": 360238,
-      "lines": 15450
+      "lines": 15385
     },
     {
       "path": "frontend/styles/redesign-v2.css",
-      "bytes": 263467,
+      "bytes": 262826,
-      "lines": 8569
+      "lines": 8554
     },
     {
       "path": "frontend/index.html",

app/frontend/styles/redesign-v2.css

@@ -751,9 +751,6 @@ body.sidebar-collapsed .status-bar { left: 64px; }
     min-height: 50px;
     padding: 6px 8px;
   }
-  .market-tape { display: none; }
-  .header-actions { width: 100%; }
-  .header-command-group { position: absolute; }
   .module-nav,
   body.sidebar-collapsed .module-nav {
     inset: auto 0 0;
@@ -769,14 +766,6 @@ body.sidebar-collapsed .status-bar { left: 64px; }
     border: 0;
     border-top: 1px solid var(--r2-line);
   }
-  .sidebar-brand,
-  .module-nav .nav-group-label,
-  .sidebar-collapse-button,
-  .module-nav .market-sub-tab { display: none; }
-  .module-nav .nav-group,
-  body.sidebar-collapsed .module-nav .nav-group { display: contents; }
-  .module-nav .module-tab,
-  body.sidebar-collapsed .module-nav .module-tab { display: none; }
   .module-nav .module-tab.mobile-primary-tab,
   body.sidebar-collapsed .module-nav .module-tab.mobile-primary-tab {
     min-height: 54px;
@@ -789,12 +778,8 @@ body.sidebar-collapsed .status-bar { left: 64px; }
     padding: 3px 2px;
     font-size: 10px;
   }
-  .module-nav .module-tab.mobile-primary-tab span { display: inline; }
   .app-main { width: 100%; margin: 0; padding: 0 8px 16px; overflow: visible; }
   .overview-strip { margin-inline: -8px; padding-inline: 8px; overflow-x: auto; }
-  .overview-strip .metric:nth-of-type(n + 4),
-  .overview-strip .metric-wide { display: none; }
-  .overview-toggle { display: none; }
   .redesigned-page-head { align-items: flex-start; flex-wrap: wrap; margin-top: 12px; }
   .redesigned-page-head .section-title-group { width: 100%; flex-wrap: wrap; }
   .redesigned-page-head .toolbar-controls { width: 100%; margin-left: 0; justify-content: space-between; }

app/frontend/styles/styles.css

@@ -4775,10 +4775,6 @@ body.sidebar-collapsed .sidebar-collapse-button .lucide {
 }
 
 @media (min-width: 721px) and (max-width: 1279px) {
-  .market-tape {
-    display: none;
-  }
-
   .app-header {
     grid-template-columns: 190px minmax(0, 1fr) auto;
   }
@@ -4980,21 +4976,6 @@ body.sidebar-collapsed .sidebar-collapse-button .lucide {
     box-shadow: 0 -4px 18px rgba(24, 34, 45, 0.07);
   }
 
-  .module-nav .nav-brand,
-  .module-nav .nav-group-label,
-  .module-nav .market-sub-tab,
-  .module-nav .sidebar-collapse-button {
-    display: none;
-  }
-
-  .module-nav .nav-group,
-  body.sidebar-collapsed .module-nav .nav-group {
-    display: contents;
-    margin: 0;
-    padding: 0;
-    border: 0;
-  }
-
   .module-nav .module-tab,
   body.sidebar-collapsed .module-nav .module-tab {
     min-height: 54px;
@@ -5009,11 +4990,6 @@ body.sidebar-collapsed .sidebar-collapse-button .lucide {
     text-align: center;
   }
 
-  .module-nav .module-tab.mobile-primary-tab,
-  body.sidebar-collapsed .module-nav .module-tab.mobile-primary-tab {
-    display: flex;
-  }
-
   .module-nav .module-tab span,
   body.sidebar-collapsed .module-nav .module-tab span {
     display: block;
@@ -13017,10 +12993,6 @@ button.account-role-badge:focus-visible { outline: 2px solid var(--blue); outlin
 }
 
 @media (max-width: 720px) {
-  body.mentor-directory-open {
-    overflow: hidden;
-  }
-
   .mentor-layout {
     height: auto;
     min-height: 580px;
@@ -14874,13 +14846,6 @@ dialog::backdrop {
     width: 100%;
   }
 
-  body,
-  body.sidebar-collapsed {
-    display: block;
-    min-height: 100dvh;
-    padding-bottom: calc(68px + env(safe-area-inset-bottom));
-  }
-
   .app-header {
     width: 100%;
     height: 108px;
@@ -14893,10 +14858,6 @@ dialog::backdrop {
     background: rgba(255, 255, 255, .98);
   }
 
-  .brand-block {
-    height: 42px;
-  }
-
   .brand-block .brand-mark,
   .brand-block .brand-logo {
     width: 34px;
@@ -14912,20 +14873,6 @@ dialog::backdrop {
     font-size: 16px;
   }
 
-  .header-actions {
-    position: absolute;
-    inset: 56px 10px auto;
-    display: flex;
-    justify-content: space-between;
-    gap: 6px;
-  }
-
-  .header-date-group {
-    height: 42px;
-    min-width: 0;
-    flex: 1;
-  }
-
   .header-date-group .date-input {
     width: 112px;
     flex: 1;
@@ -14937,12 +14884,6 @@ dialog::backdrop {
     min-width: 30px;
   }
 
-  .header-actions > .icon-button {
-    width: 40px;
-    min-width: 40px;
-    min-height: 42px;
-  }
-
   .header-menu-button {
     display: grid;
   }
@@ -15056,9 +14997,7 @@ dialog::backdrop {
     font-size: 14px;
   }
 
-  .overview-strip .metric:nth-of-type(1) { grid-column: 2; grid-row: 1; }
   .overview-strip .metric:nth-of-type(2) { grid-column: 3; grid-row: 1; border-right: 0; }
-  .overview-strip .metric:nth-of-type(3) { grid-column: 2; grid-row: 2; }
   .overview-strip .metric:nth-of-type(4) { grid-column: 3; grid-row: 2; border-right: 0; }
   .overview-strip .metric:nth-of-type(5) { grid-column: 1 / 2; grid-row: 3; border-bottom: 0; }
   .overview-strip .metric:nth-of-type(6) { grid-column: 2 / 4; grid-row: 3; border-right: 0; border-bottom: 0; }
@@ -15315,10 +15254,6 @@ dialog::backdrop {
     overflow-y: auto;
   }
 
-  .curated-strategy-list {
-    grid-template-columns: 1fr;
-  }
-
   .quant-universe-grid {
     grid-template-columns: 1fr 1fr;
   }

app/tests/e2e/app-shell.spec.js

@@ -1803,21 +1803,29 @@ test("heart breathing prepares once then contracts on each exhale", async ({ pag
   await expect(page.locator(".heart-breath-ripple span").first()).toHaveCSS("transition-duration", "4s");
 });
 
-test("stylesheet layers do not repeat identical top-level rules", async ({ page }) => {
+test("stylesheet layers do not repeat identical rules in the same cascade context", async ({ page }) => {
   await mockApplication(page, session("admin", true));
   await page.goto("/index.html");
 
   const duplicates = await page.evaluate(() => {
     const occurrences = new Map();
-    for (const sheet of Array.from(document.styleSheets)) {
+    const visitRules = (rules, href, context = []) => {
-      const href = sheet.href ? new URL(sheet.href).pathname : "inline";
+      for (const rule of Array.from(rules || [])) {
-      for (const rule of Array.from(sheet.cssRules || [])) {
+        if (typeof rule.selectorText === "string" && rule.style) {
-        if (typeof rule.selectorText !== "string" || !rule.style) continue;
+          const key = `${context.join("\u0001")}\u0000${rule.selectorText}\u0000${rule.style.cssText}`;
-        const key = `${rule.selectorText}\u0000${rule.style.cssText}`;
           const rows = occurrences.get(key) || [];
           rows.push(href);
           occurrences.set(key, rows);
+          continue;
         }
+        if (!rule.cssRules) continue;
+        const condition = rule.conditionText || rule.media?.mediaText || rule.name || "";
+        visitRules(rule.cssRules, href, [...context, `${rule.type}:${condition}`]);
+      }
+    };
+    for (const sheet of Array.from(document.styleSheets)) {
+      const href = sheet.href ? new URL(sheet.href).pathname : "inline";
+      visitRules(sheet.cssRules, href);
     }
     return Array.from(occurrences.entries())
       .filter(([, paths]) => new Set(paths).size > 1)

app/tests/preservation_helpers.py

@@ -29,10 +29,11 @@ RETIRED_FRONTEND_SOURCE_RANGES = (
 )
 AUDITED_FRONTEND_SOURCE_LINE_COUNT = 9283
 
-# CR-12 removes only declarations that are repeated verbatim by a later
+# CR-12 and CR-13 remove only declarations repeated by a later stylesheet
-# stylesheet layer under the same top-level cascade context. Keeping the exact
+# layer under the same cascade context. Entries are either an exact retired
-# source fragments here makes every other byte of the accepted CSS baseline a
+# fragment or an exact (source, replacement) pair when surrounding context is
-# preservation requirement.
+# needed to identify one nested occurrence. Every other byte remains part of
+# the accepted CSS baseline.
 AUDITED_CSS_RETIREMENTS = {
     "styles.css": (
         ".workspace-view.active-view {\n  display: block;\n}\n\n",
@@ -44,6 +45,78 @@ AUDITED_CSS_RETIREMENTS = {
             "  display: block;\n"
             "}\n\n"
         ),
+        (
+            (
+                "@media (min-width: 721px) and (max-width: 1279px) {\n"
+                "  .market-tape {\n"
+                "    display: none;\n"
+                "  }\n\n"
+                "  .app-header {"
+            ),
+            (
+                "@media (min-width: 721px) and (max-width: 1279px) {\n"
+                "  .app-header {"
+            ),
+        ),
+        (
+            "  .module-nav .nav-brand,\n"
+            "  .module-nav .nav-group-label,\n"
+            "  .module-nav .market-sub-tab,\n"
+            "  .module-nav .sidebar-collapse-button {\n"
+            "    display: none;\n"
+            "  }\n\n"
+        ),
+        (
+            "  .module-nav .nav-group,\n"
+            "  body.sidebar-collapsed .module-nav .nav-group {\n"
+            "    display: contents;\n"
+            "    margin: 0;\n"
+            "    padding: 0;\n"
+            "    border: 0;\n"
+            "  }\n\n"
+        ),
+        (
+            "  .module-nav .module-tab.mobile-primary-tab,\n"
+            "  body.sidebar-collapsed .module-nav .module-tab.mobile-primary-tab {\n"
+            "    display: flex;\n"
+            "  }\n\n"
+        ),
+        "  body.mentor-directory-open {\n    overflow: hidden;\n  }\n\n",
+        (
+            "  body,\n"
+            "  body.sidebar-collapsed {\n"
+            "    display: block;\n"
+            "    min-height: 100dvh;\n"
+            "    padding-bottom: calc(68px + env(safe-area-inset-bottom));\n"
+            "  }\n\n"
+        ),
+        "  .brand-block {\n    height: 42px;\n  }\n\n",
+        (
+            "  .header-actions {\n"
+            "    position: absolute;\n"
+            "    inset: 56px 10px auto;\n"
+            "    display: flex;\n"
+            "    justify-content: space-between;\n"
+            "    gap: 6px;\n"
+            "  }\n\n"
+        ),
+        (
+            "  .header-date-group {\n"
+            "    height: 42px;\n"
+            "    min-width: 0;\n"
+            "    flex: 1;\n"
+            "  }\n\n"
+        ),
+        (
+            "  .header-actions > .icon-button {\n"
+            "    width: 40px;\n"
+            "    min-width: 40px;\n"
+            "    min-height: 42px;\n"
+            "  }\n\n"
+        ),
+        "  .overview-strip .metric:nth-of-type(1) { grid-column: 2; grid-row: 1; }\n",
+        "  .overview-strip .metric:nth-of-type(3) { grid-column: 2; grid-row: 2; }\n",
+        "  .curated-strategy-list {\n    grid-template-columns: 1fr;\n  }\n\n",
     ),
     "renovation.css": (
         ".overview-strip .sentiment-block { padding-left: 0; }\n",
@@ -54,6 +127,27 @@ AUDITED_CSS_RETIREMENTS = {
     ),
     "redesign-v2.css": (
         "#dragonView .dragon-operation-table .dragon-col-reason { width: auto; }\n",
+        (
+            "  .market-tape { display: none; }\n"
+            "  .header-actions { width: 100%; }\n"
+            "  .header-command-group { position: absolute; }\n"
+        ),
+        (
+            "  .sidebar-brand,\n"
+            "  .module-nav .nav-group-label,\n"
+            "  .sidebar-collapse-button,\n"
+            "  .module-nav .market-sub-tab { display: none; }\n"
+            "  .module-nav .nav-group,\n"
+            "  body.sidebar-collapsed .module-nav .nav-group { display: contents; }\n"
+            "  .module-nav .module-tab,\n"
+            "  body.sidebar-collapsed .module-nav .module-tab { display: none; }\n"
+        ),
+        "  .module-nav .module-tab.mobile-primary-tab span { display: inline; }\n",
+        (
+            "  .overview-strip .metric:nth-of-type(n + 4),\n"
+            "  .overview-strip .metric-wide { display: none; }\n"
+            "  .overview-toggle { display: none; }\n"
+        ),
     ),
 }
 
@@ -154,8 +248,9 @@ def assert_moved_asset_matches(
     if original_relative in AUDITED_CSS_RETIREMENTS:
         original = (ORIGINAL_STATIC / original_relative).read_text(encoding="utf-8")
         for retired in AUDITED_CSS_RETIREMENTS[original_relative]:
-            testcase.assertEqual(original.count(retired), 1, retired)
+            source, replacement = retired if isinstance(retired, tuple) else (retired, "")
-            original = original.replace(retired, "", 1)
+            testcase.assertEqual(original.count(source), 1, source)
+            original = original.replace(source, replacement, 1)
         testcase.assertEqual(
             (FRONTEND_ROOT / target_relative).read_text(encoding="utf-8"),
             original,

docs/governance/code-reduction.md

@@ -321,6 +321,33 @@
 本批基线为`xiaobai-reduction-11-heaven-interpret-fix-20260802`；检查点为
 `xiaobai-reduction-12-css-exact-duplicates-20260802`。
 
+## CR-13验收口径
+
+- 本批只处理不同样式文件中、处于浏览器规范化后完全相同媒体条件下、选择器与完整CSSOM声明完全
+  相同的规则；不同媒体上下文、同文件重复、近似声明、动画和问天隔离样式继续保留。
+- 删除的必须是较早加载的副本，较晚样式层继续提供相同声明；媒体条件、规则顺序、选择器优先级、
+  变量、HTML、JavaScript和主题逻辑不得改变。
+- 保真门禁必须逐段登记允许退休的原始源码；浏览器门禁必须递归遍历嵌套规则，并只将同一上下文内
+  跨文件的完整重复判为失败。
+- 390×844明暗主题、1000×800中等宽度和1000×600低高度断点必须保持原计算样式与视觉结果。
+
+## CR-13结果
+
+- 浏览器CSSOM确认22组跨文件嵌套重复：1组位于721-1279px媒体条件，12组位于720px移动端条件，
+  9组位于720px或1023px低高度复合条件；全部删除较早层副本，后层规则原样保留。
+- `styles.css`减少65行，`redesign-v2.css`减少15行，生产CSS合计净减少80行、约1.9 KB；没有新增
+  兼容覆盖、声明值、选择器或样式文件。
+- Playwright门禁由顶层扫描扩展为递归上下文扫描，修改后同一嵌套上下文的跨文件完整重复为0；同文件
+  重复和不同上下文规则不在本批范围，未被误删。
+- 1000×800和1000×600修改前后截图逐字节一致；390×844明暗主题的关键显示、定位、间距、网格、
+  溢出和导航状态一致，页面目视无差异。
+- 候选330项、CSS/前端契约33项、迁移对照63项及46项Playwright全部通过；24个JavaScript文件、
+  API/架构注册表和SQLite完整性检查通过。
+- 本批不修改页面布局、颜色、字体、间距、主题、动画、业务功能、API、数据库、数据源、LLM或部署。
+
+本批基线为`xiaobai-reduction-12-css-exact-duplicates-20260802`；检查点为
+`xiaobai-reduction-13-css-nested-duplicates-20260802`。
+
 ## 人工验收记录
 
 - 2026-08-01：用户检查CR-02与CR-03运行结果，确认未发现明显异常。本记录仅表示本轮可见功能与