Add logo container and enhance login page styling

Introduced a styled wrapper for the login page logo to improve its appearance and layout consistency. Adjusted logo dimensions and applied new visual effects like gradients, shadow, and borders for a more polished design.

frontend/src/pages/LoginPage.jsx

@@ -27,7 +27,9 @@ export function LoginPage() {
   return (
     <div className="login-wrap">
       <form className="card login-card" onSubmit={submit}>
-        <img src="/nexapg-logo.svg" alt="NexaPG" className="login-logo" />
+        <div className="login-logo-wrap" aria-hidden="true">
+          <img src="/nexapg-logo.svg" alt="NexaPG" className="login-logo" />
+        </div>
         <div className="login-eyebrow">NexaPG Monitor</div>
         <h2>Welcome back</h2>
         <p className="login-subtitle">Sign in to access monitoring and query insights.</p>