account system、custom prompt

web/src/components/Header.tsx

@@ -0,0 +1,58 @@
+import { useLanguage } from '../contexts/LanguageContext';
+import { t } from '../i18n/translations';
+
+interface HeaderProps {
+  simple?: boolean; // For login/register pages
+}
+
+export function Header({ simple = false }: HeaderProps) {
+  const { language, setLanguage } = useLanguage();
+
+  return (
+    <header className="glass sticky top-0 z-50 backdrop-blur-xl">
+      <div className="max-w-[1920px] mx-auto px-6 py-4">
+        <div className="flex items-center justify-between">
+          {/* Left - Logo and Title */}
+          <div className="flex items-center gap-3">
+            <div className="w-8 h-8 rounded-full flex items-center justify-center text-xl" 
+                 style={{ background: 'linear-gradient(135deg, #F0B90B 0%, #FCD535 100%)' }}>
+              ⚡
+            </div>
+            <div>
+              <h1 className="text-xl font-bold" style={{ color: '#EAECEF' }}>
+                {t('appTitle', language)}
+              </h1>
+              <p className="text-xs mono" style={{ color: '#848E9C' }}>
+                {t('subtitle', language)}
+              </p>
+            </div>
+          </div>
+          
+          {/* Right - Language Toggle */}
+          <div className="flex gap-1 rounded p-1" style={{ background: '#1E2329' }}>
+            <button
+              onClick={() => setLanguage('zh')}
+              className="px-3 py-1.5 rounded text-xs font-semibold transition-all"
+              style={language === 'zh'
+                ? { background: '#F0B90B', color: '#000' }
+                : { background: 'transparent', color: '#848E9C' }
+              }
+            >
+              中文
+            </button>
+            <button
+              onClick={() => setLanguage('en')}
+              className="px-3 py-1.5 rounded text-xs font-semibold transition-all"
+              style={language === 'en'
+                ? { background: '#F0B90B', color: '#000' }
+                : { background: 'transparent', color: '#848E9C' }
+              }
+            >
+              EN
+            </button>
+          </div>
+        </div>
+      </div>
+    </header>
+  );
+}