fix(theme): polish dark header and toggle

Signed-off-by: XiaoSeS <87064762+XiaoSeS@users.noreply.github.com>

web/e2e/theme-toggle.spec.ts

@@ -59,9 +59,13 @@ test.describe('Light and dark theme', () => {
 
     await page.goto('/')
     await expect(page.locator('html')).not.toHaveClass(/dark/)
+    const header = page.locator('header')
+    const lightHeaderBackground = await header.evaluate((element) => getComputedStyle(element).backgroundColor)
 
     await page.getByRole('button', { name: 'Switch to dark theme' }).click()
     await expect(page.locator('html')).toHaveClass(/dark/)
+    await expect.poll(() => header.evaluate((element) => getComputedStyle(element).backgroundColor))
+      .not.toBe(lightHeaderBackground)
     await expect.poll(() => page.evaluate(() => window.localStorage.getItem('skillhub-theme'))).toBe('dark')
 
     await page.reload()
@@ -73,7 +77,7 @@ test.describe('Light and dark theme', () => {
     ).__themeAtFirstReactContent)).toBe(true)
 
     await page.getByRole('link', { name: 'Search', exact: true }).first().click()
-    await expect(page).toHaveURL(/\/search$/)
+    await expect(page).toHaveURL(/\/search(?:\?|$)/)
     await expect(page.locator('html')).toHaveClass(/dark/)
     await page.screenshot({ path: testInfo.outputPath('dark-desktop.png'), fullPage: true })
 

web/src/app/layout-header-style.test.ts

@@ -3,7 +3,11 @@ import { APP_HEADER_ELEVATED_CLASS_NAME, getAppHeaderClassName } from './layout-
 
 describe('getAppHeaderClassName', () => {
   it('keeps the header flat before the page starts scrolling', () => {
-    expect(getAppHeaderClassName(false)).not.toContain(APP_HEADER_ELEVATED_CLASS_NAME)
+    const className = getAppHeaderClassName(false)
+
+    expect(className).not.toContain(APP_HEADER_ELEVATED_CLASS_NAME)
+    expect(className).toContain('bg-background/90')
+    expect(className).not.toContain('bg-white')
   })
 
   it('adds a subtle drop shadow after the header becomes sticky', () => {

web/src/app/layout-header-style.ts

@@ -1,9 +1,10 @@
 import { cn } from '@/shared/lib/utils'
 
 export const APP_HEADER_BASE_CLASS_NAME =
-  'sticky top-0 z-50 flex items-center justify-between border-b bg-white px-6 py-4 transition-shadow duration-200 md:px-12'
+  'sticky top-0 z-50 flex items-center justify-between border-b border-border/70 bg-background/90 px-6 py-4 backdrop-blur-xl transition-[background-color,border-color,box-shadow] duration-200 supports-[backdrop-filter]:bg-background/80 md:px-12'
 
-export const APP_HEADER_ELEVATED_CLASS_NAME = 'shadow-[0_10px_24px_-20px_rgba(15,23,42,0.32)]'
+export const APP_HEADER_ELEVATED_CLASS_NAME =
+  'shadow-[0_12px_30px_-24px_hsl(var(--foreground)/0.45)]'
 
 export function getAppHeaderClassName(isElevated: boolean): string {
   return cn(APP_HEADER_BASE_CLASS_NAME, isElevated && APP_HEADER_ELEVATED_CLASS_NAME)

web/src/app/layout.tsx

@@ -83,7 +83,7 @@ export function Layout() {
         <div
           className="absolute top-0 right-0 w-[600px] h-[500px] rounded-full opacity-90"
           style={{
-            background: 'radial-gradient(ellipse at 70% 20%, rgba(184,94,255,0.25) 0%, rgba(106,109,255,0.15) 40%, transparent 70%)',
+            background: 'radial-gradient(ellipse at 70% 20%, hsl(var(--glow-accent) / 0.12) 0%, hsl(var(--glow-primary) / 0.07) 40%, transparent 70%)',
             filter: 'blur(60px)',
           }}
         />

web/src/index.css

@@ -51,33 +51,33 @@
   }
 
   .dark {
-    /* Dark theme (preserved, not default) */
-    --background: 222 47% 6%;
-    --foreground: 210 40% 96%;
-    --card: 222 40% 9%;
-    --card-foreground: 210 40% 96%;
-    --popover: 222 40% 9%;
-    --popover-foreground: 210 40% 96%;
-    --primary: 239 100% 75%;
-    --primary-foreground: 222 47% 6%;
-    --secondary: 222 30% 13%;
-    --secondary-foreground: 210 30% 85%;
-    --muted: 222 25% 15%;
-    --muted-foreground: 215 20% 55%;
-    --accent: 271 100% 72%;
+    /* Cool ink surfaces: distinct depth without near-black dead zones. */
+    --background: 222 30% 10%;
+    --foreground: 216 28% 93%;
+    --card: 222 25% 14%;
+    --card-foreground: 216 28% 93%;
+    --popover: 222 24% 15%;
+    --popover-foreground: 216 28% 93%;
+    --primary: 241 92% 74%;
+    --primary-foreground: 222 30% 10%;
+    --secondary: 222 20% 18%;
+    --secondary-foreground: 216 24% 88%;
+    --muted: 222 18% 19%;
+    --muted-foreground: 216 14% 66%;
+    --accent: 272 86% 72%;
     --accent-foreground: 0 0% 100%;
-    --destructive: 0 72% 55%;
+    --destructive: 0 72% 61%;
     --destructive-foreground: 0 0% 100%;
-    --border: 222 20% 18%;
-    --input: 222 20% 18%;
-    --ring: 239 100% 75%;
-    --surface-glass: 222 35% 11%;
-    --glow-primary: 239 100% 75%;
-    --glow-accent: 271 100% 72%;
-    --text-secondary: 215 20% 72%;
-    --text-muted: 215 16% 63%;
-    --text-placeholder: 215 14% 48%;
-    --border-card: 222 20% 18%;
+    --border: 222 16% 25%;
+    --input: 222 16% 25%;
+    --ring: 241 92% 74%;
+    --surface-glass: 222 24% 14%;
+    --glow-primary: 241 92% 70%;
+    --glow-accent: 272 80% 68%;
+    --text-secondary: 216 17% 76%;
+    --text-muted: 216 14% 66%;
+    --text-placeholder: 216 12% 54%;
+    --border-card: 222 16% 24%;
   }
 }
 

web/src/shared/components/theme-toggle.tsx

@@ -21,24 +21,29 @@ export function ThemeToggle({ className }: ThemeToggleProps) {
       title={label}
       onClick={toggleTheme}
       className={cn(
-        'group relative inline-flex h-11 w-11 shrink-0 items-center justify-center overflow-hidden rounded-full border border-border/70 bg-card/80 text-muted-foreground shadow-sm transition-colors duration-200 hover:border-primary/35 hover:bg-secondary hover:text-foreground focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-ring focus-visible:ring-offset-2 focus-visible:ring-offset-background',
+        'group relative inline-flex h-10 w-[4.5rem] shrink-0 items-center rounded-full border border-border bg-muted/70 p-1 text-muted-foreground shadow-sm transition-[background-color,border-color] duration-200 hover:border-primary/40 hover:bg-muted focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-ring focus-visible:ring-offset-2 focus-visible:ring-offset-background',
         className,
       )}
     >
-      <Sun
+      <span
         aria-hidden="true"
         className={cn(
-          'absolute h-[18px] w-[18px] transition-[opacity,transform] duration-200 motion-reduce:transition-none',
-          isDark ? 'rotate-90 scale-75 opacity-0' : 'rotate-0 scale-100 opacity-100',
-        )}
-      />
-      <Moon
-        aria-hidden="true"
-        className={cn(
-          'absolute h-[18px] w-[18px] transition-[opacity,transform] duration-200 motion-reduce:transition-none',
-          isDark ? 'rotate-0 scale-100 opacity-100' : '-rotate-90 scale-75 opacity-0',
+          'absolute left-1 top-1 h-8 w-8 rounded-full border border-border/80 bg-card shadow-[0_3px_10px_-4px_hsl(var(--foreground)/0.45)] transition-transform duration-200 ease-out motion-reduce:transition-none',
+          isDark && 'translate-x-8',
         )}
       />
+      <span className="relative z-10 inline-flex h-8 w-8 items-center justify-center">
+        <Sun
+          aria-hidden="true"
+          className={cn('h-4 w-4 transition-colors duration-200', !isDark && 'text-foreground')}
+        />
+      </span>
+      <span className="relative z-10 inline-flex h-8 w-8 items-center justify-center">
+        <Moon
+          aria-hidden="true"
+          className={cn('h-4 w-4 transition-colors duration-200', isDark && 'text-foreground')}
+        />
+      </span>
     </button>
   )
 }