diff --git a/src/i18n/locales/en.ts b/src/i18n/locales/en.ts
index f82a337..6ad7155 100644
--- a/src/i18n/locales/en.ts
+++ b/src/i18n/locales/en.ts
@@ -494,7 +494,7 @@ export const en: Record<MessageKey, string> = {
   'usage.stat.successMetaTitle': '{success} succeeded, {failed} failed, {canceled} canceled',
   'usage.stat.averageLatency': 'Average Latency',
   'usage.stat.tps': 'TPS',
-  'usage.stat.performanceMeta': '{samples} samples · RPM {rpm} · {latency} ms',
+  'usage.stat.performanceMeta': '{samples} samples · RPM {rpm}',
   'usage.stat.performanceMetaTitle': 'TPS {tps} (weighted by total latency), {samples} valid samples, RPM {rpm}, average latency {latency} ms',
   'usage.stat.cacheHitRate': 'Cache Hit Rate',
   'usage.stat.cacheHitMeta': 'Read {hit} · Input {input}',
@@ -1456,8 +1456,8 @@ export const en: Record<MessageKey, string> = {
   'kernel.install.completed': '{version} installed',
   'kernel.error.progressListener': 'Failed to listen for download progress: {error}',
   'kernel.action.start': 'start',
-  'kernel.action.stop': 'stop',
-  'kernel.action.restart': 'restart',
+  'kernel.action.stop': 'Stop',
+  'kernel.action.restart': 'Restart',
   'kernel.notice.actionSuccess': 'Core {action} succeeded',
   'kernel.notice.actionFailed': 'Core {action} failed: {error}',
   'kernel.notice.networkRestarted': 'Network settings saved and the core restarted',
diff --git a/src/pages/ConfigPanel.tsx b/src/pages/ConfigPanel.tsx
index 9f9b433..69997ce 100644
--- a/src/pages/ConfigPanel.tsx
+++ b/src/pages/ConfigPanel.tsx
@@ -984,6 +984,7 @@ export function ConfigPanelPage() {
 
   return (
     <section className="page config-page">
+      <h1 className="sr-only">{t('app.nav.config')}</h1>
       <div className="agent-subpage-tabs config-subpage-tabs" role="tablist" aria-label={t('config.tabs.label')}>
         <button
           type="button"
@@ -1694,7 +1695,7 @@ export function ConfigPanelPage() {
                     </button>
                   ))}
                 </div>
-                <small title={settings?.routingStrategy || undefined}>
+                <small className="sr-only" title={settings?.routingStrategy || undefined}>
                   {loading
                     ? t('common.loading')
                     : settings === null
diff --git a/src/pages/Kernel.tsx b/src/pages/Kernel.tsx
index 4ca4ff2..5000edb 100644
--- a/src/pages/Kernel.tsx
+++ b/src/pages/Kernel.tsx
@@ -219,6 +219,7 @@ export function KernelPage({ view = 'home' }: { view?: KernelView }) {
 
   return (
     <section className="page kernel-page home-page">
+      <h1 className="sr-only">{t('app.nav.home')}</h1>
       <div className="kernel-layout home-layout">
         <div className="panel control-panel">
           <div className="panel-heading">
@@ -426,7 +427,6 @@ export function KernelPage({ view = 'home' }: { view?: KernelView }) {
         <button
           type="button"
           className="home-quick-card"
-          aria-label="Token 统计与请求日志"
           onClick={() => window.dispatchEvent(new CustomEvent('app:navigate', { detail: 'usage-records' }))}
         >
           <span className="home-quick-icon">
diff --git a/src/pages/ThinkingAliasesPage.tsx b/src/pages/ThinkingAliasesPage.tsx
index 694d213..c74b644 100644
--- a/src/pages/ThinkingAliasesPage.tsx
+++ b/src/pages/ThinkingAliasesPage.tsx
@@ -558,6 +558,11 @@ export function ThinkingAliasesPage({ embedded = false }: { embedded?: boolean }
       <MessageNotice tone="success" message={!error ? notice : null} onDismiss={() => setNotice('')} />
 
       <header className="management-header">
+        <div>
+          {embedded
+            ? <h2>{t('app.nav.thinkingAliases')}</h2>
+            : <h1>{t('app.nav.thinkingAliases')}</h1>}
+        </div>
         <div className="management-heading-actions">
           <span className="muted-summary">{entries.length}</span>
           <button
diff --git a/src/pages/VersionManagementPage.tsx b/src/pages/VersionManagementPage.tsx
index f931897..66c17bf 100644
--- a/src/pages/VersionManagementPage.tsx
+++ b/src/pages/VersionManagementPage.tsx
@@ -9,6 +9,7 @@ import {
   RefreshCw,
   RotateCcw,
   Trash2,
+  X,
 } from 'lucide-react';
 import { useCoreRuntime } from '../coreRuntime';
 import { useCoreUpdate } from '../coreUpdate';
@@ -485,16 +486,16 @@ export function VersionManagementPage() {
     : t('common.close');
 
   const installDialogActionDisabled = (installing || progress?.running) && (cancellingInstall || !progress?.cancellable);
+  const closeCustomMirrorDialog = () => {
+    setCustomMirrorDialogOpen(false);
+    setCustomMirrorDraft('');
+    setVersionSourceError('');
+  };
+
   const customMirrorDialogRef = useDialogFocusTrap<HTMLFormElement>({
     active: customMirrorDialogOpen,
     initialFocusRef: customMirrorInputRef,
-    onEscape: versionSourceSaving
-      ? undefined
-      : () => {
-          setCustomMirrorDialogOpen(false);
-          setCustomMirrorDraft('');
-          setVersionSourceError('');
-        },
+    onEscape: versionSourceSaving ? undefined : closeCustomMirrorDialog,
     preventEscape: versionSourceSaving,
   });
   const confirmUpdateDialogRef = useDialogFocusTrap<HTMLElement>({
@@ -718,8 +719,20 @@ export function VersionManagementPage() {
             }}
           >
             <div className="install-dialog-heading">
-              <span>{t('kernel.versions.downloadSource')}</span>
-              <h2 id="custom-mirror-dialog-title">{t('kernel.versions.customMirrorDialogTitle')}</h2>
+              <div>
+                <span>{t('kernel.versions.downloadSource')}</span>
+                <h2 id="custom-mirror-dialog-title">{t('kernel.versions.customMirrorDialogTitle')}</h2>
+              </div>
+              <button
+                type="button"
+                className="icon-button quiet"
+                onClick={closeCustomMirrorDialog}
+                disabled={versionSourceSaving}
+                title={t('common.close')}
+                aria-label={t('common.close')}
+              >
+                <X size={18} aria-hidden="true" />
+              </button>
             </div>
             <p className="custom-mirror-dialog-description">
               {t('kernel.versions.customMirrorDialogDescription')}
@@ -758,11 +771,7 @@ export function VersionManagementPage() {
                 type="button"
                 className="secondary-button"
                 disabled={versionSourceSaving}
-                onClick={() => {
-                  setCustomMirrorDialogOpen(false);
-                  setCustomMirrorDraft('');
-                  setVersionSourceError('');
-                }}
+                onClick={closeCustomMirrorDialog}
               >
                 {t('common.cancel')}
               </button>
diff --git a/src/styles.css b/src/styles.css
index 964fdf6..77dbe72 100644
--- a/src/styles.css
+++ b/src/styles.css
@@ -106,7 +106,7 @@
   --theme-f8f6f1: #f8f6f1;
   --theme-faf8f2: #faf8f2;
   --theme-faf8f4: #faf8f4;
-  --theme-faf9f5: #ffffff;
+  --theme-faf9f5: #f6f7f5;
   --theme-fdf1ee: #fdf1ee;
   --theme-fff: #fff;
   --theme-fff1ee: #fff1ee;
@@ -115,7 +115,7 @@
   --theme-fffdf8: #fffdf8;
   --theme-ffffff: #ffffff;
 
-  --bg-secondary: #ffffff;
+  --bg-secondary: #f6f7f5;
   --bg-primary: #ffffff;
   --bg-tertiary: #f8fafc;
   --bg-hover: #f1f5f9;
@@ -8568,7 +8568,7 @@ textarea:focus-visible {
 .usage-overview-layout {
   display: grid;
   grid-template-columns: minmax(0, 1.35fr) minmax(260px, 0.65fr);
-  grid-template-rows: auto minmax(280px, 1fr);
+  grid-template-rows: max-content minmax(280px, 1fr);
   gap: 14px;
   align-items: stretch;
   overflow-x: hidden;
diff --git a/src/styles/ui-refinements.css b/src/styles/ui-refinements.css
index 76b2d44..0a9e6ad 100644
--- a/src/styles/ui-refinements.css
+++ b/src/styles/ui-refinements.css
@@ -4,12 +4,12 @@
 
 /* 1. Global Light Theme Surface & Contrast Variables */
 :root {
-  --bg-secondary: #ffffff;
+  --bg-secondary: #f6f7f5;
   --bg-primary: #ffffff;
   --bg-card: #ffffff;
-  --bg-tertiary: #f8fafc;
-  --bg-hover: #f1f5f9;
-  --bg-quinary: #f8fafc;
+  --bg-tertiary: #eff3f0;
+  --bg-hover: #f6f8f6;
+  --bg-quinary: #f9faf9;
   --border-color: #e2e8f0;
   --border-secondary: #f1f5f9;
   --border-primary: #cbd5e1;
@@ -18,7 +18,7 @@
   --text-secondary: #1e293b;
   --text-tertiary: #334155;
   --text-quaternary: #475569;
-  --theme-faf9f5: #ffffff;
+  --theme-faf9f5: #f6f7f5;
   --theme-faf8f4: #ffffff;
   --theme-faf8f2: #ffffff;
   --theme-fffdf8: #ffffff;
@@ -216,6 +216,13 @@ body, html, #root {
   border: 1px solid var(--border-color);
   border-radius: 8px;
   padding: 6px 12px;
+  flex-shrink: 0;
+  white-space: nowrap;
+}
+
+.client-api-panel .client-api-meta {
+  white-space: nowrap;
+  flex-shrink: 0;
 }
 
 .client-api-card {
@@ -233,8 +240,16 @@ body, html, #root {
 }
 
 .client-api-card-heading {
-  width: 144px;
-  flex-basis: 144px;
+  min-width: 144px;
+  width: auto;
+  flex: 0 1 auto;
+}
+
+.client-api-card-heading .client-api-format-tag,
+.client-api-card-heading span {
+  font-size: var(--font-size-caption);
+  white-space: nowrap;
+  overflow: visible;
 }
 
 .client-api-card-heading .client-api-format-tag,
@@ -450,6 +465,8 @@ body, html, #root {
 }
 
 .oauth-card {
+  display: flex;
+  flex-direction: column;
   padding: 22px;
   border: 1px solid var(--border-color);
   border-radius: 12px;
@@ -458,6 +475,16 @@ body, html, #root {
   transition: border-color 0.2s ease, box-shadow 0.2s ease, transform 0.2s ease;
 }
 
+.oauth-card .oauth-card-body,
+.oauth-card .oauth-hint {
+  flex: 1;
+}
+
+.oauth-card .oauth-card-actions,
+.oauth-card > button.primary-button {
+  margin-top: auto;
+}
+
 .oauth-card:hover {
   border-color: var(--border-primary);
   box-shadow: var(--ui-card-hover-shadow);
@@ -786,7 +813,7 @@ body, html, #root {
 }
 
 .secondary-button {
-  background: #ffffff;
+  background: var(--bg-primary);
   border: 1px solid var(--border-color);
   color: var(--text-secondary);
   border-radius: 8px;
@@ -800,6 +827,18 @@ body, html, #root {
   color: var(--text-primary);
 }
 
+:root[data-theme='dark'] .secondary-button {
+  background: var(--bg-card);
+  border-color: var(--border-color);
+  color: var(--text-primary);
+}
+
+:root[data-theme='dark'] .secondary-button:hover:not(:disabled) {
+  background: var(--bg-tertiary);
+  border-color: var(--border-primary);
+  color: var(--text-primary);
+}
+
 .danger-button {
   background: #fff1f2;
   border: 1px solid #fecdd3;
@@ -815,6 +854,50 @@ body, html, #root {
   color: #ffffff;
 }
 
+:root[data-theme='dark'] .danger-button {
+  background: rgba(225, 29, 72, 0.14);
+  border-color: rgba(225, 29, 72, 0.35);
+  color: #fb7185;
+}
+
+:root[data-theme='dark'] .danger-button:hover:not(:disabled) {
+  background: #e11d48;
+  border-color: #e11d48;
+  color: #ffffff;
+}
+
+/* Quota Progress Bar Polish */
+.real-quota-track {
+  height: 8px;
+  overflow: hidden;
+  border-radius: 999px;
+  background: var(--bg-hover);
+}
+
+.real-quota-track span {
+  display: block;
+  height: 100%;
+  border-radius: inherit;
+  background: var(--ui-accent);
+}
+
+/* Agent List & Config Scrollbar Polish */
+.agent-list-items::-webkit-scrollbar,
+.agent-config-scroll-region::-webkit-scrollbar {
+  width: 6px;
+}
+
+.agent-list-items::-webkit-scrollbar-thumb,
+.agent-config-scroll-region::-webkit-scrollbar-thumb {
+  background: var(--border-primary);
+  border-radius: 4px;
+}
+
+.agent-list-items::-webkit-scrollbar-track,
+.agent-config-scroll-region::-webkit-scrollbar-track {
+  background: transparent;
+}
+
 /* Responsive Shell (Preserved from existing accessibility rules) */
 @media (max-width: 900px) {
   .app-shell:not(.app-shell-easy-mode) {
diff --git a/tests/app-shell-accessibility-ui.cjs b/tests/app-shell-accessibility-ui.cjs
index bf804e0..0dda666 100644
--- a/tests/app-shell-accessibility-ui.cjs
+++ b/tests/app-shell-accessibility-ui.cjs
@@ -27,7 +27,7 @@ const path = require('node:path');
 
     assert.equal(await page.getByRole('heading', { level: 1, name: '首页' }).count(), 1);
 
-    await page.getByRole('button', { name: '使用记录' }).click();
+    await page.locator('.nav-section').getByRole('button', { name: '使用记录' }).click();
     const tabs = page.getByRole('tab');
     assert.equal(await tabs.count(), 5);
     assert.deepEqual(await tabs.evaluateAll((elements) => elements
@@ -39,7 +39,7 @@ const path = require('node:path');
     await page.getByRole('tab', { name: /数据管理/ }).click();
     assert.equal(await page.locator('.usage-filter-panel').count(), 0);
 
-    await page.getByRole('button', { name: '高级功能' }).click();
+    await page.locator('.nav-section').getByRole('button', { name: '高级功能' }).click();
     assert.equal(await page.locator('h1').count(), 1);
     const configTabs = page.locator('.config-subpage-tabs').getByRole('tab');
     assert.deepEqual(await configTabs.evaluateAll((elements) => elements
@@ -60,7 +60,7 @@ const path = require('node:path');
     assert.equal(await addKey.evaluate((element) => document.activeElement === element), true);
 
     await page.setViewportSize({ width: 640, height: 600 });
-    await page.getByRole('button', { name: '首页' }).click();
+    await page.locator('.nav-section').getByRole('button', { name: '首页' }).click();
     const sidebarHeight = await page.locator('.sidebar').evaluate((element) => element.getBoundingClientRect().height);
     assert.ok(sidebarHeight < 150, `compact sidebar is too tall: ${sidebarHeight}px`);