i dont know how to make the nav-bar at the top of viewport and use css flexbox
**Your code so far**
/* file: index.html */
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1">
<link rel="stylesheet" href="styles.css">
</head>
<body>
<header id="header">
<img src="https://cdn.freecodecamp.org/testable-projects-fcc/images/product-landing-page-logo.png" alt="original trombone" id="header-img" />
<nav id="nav-bar">
<p><a class="nav-link" href="#features">Features</a></p>
<p><a class="nav-link" href="#how-it-works">How It Works</a></p>
<p><a class="nav-link" href="#pricing">Pricing</a></p>
</nav>
</header>
<form id="form" action="https://www.freecodecamp.com/email-submit">
<div>Handcrafted, home-made masterpieces
<input id="email" name="email" type="email" placeholder="enter your email" required /></div>
<input type="submit" id="submit" value="Get Started">
</form>
<main>
<section id="features">
<div><h1>Premium Materials</h1>
<p>Our trombones use the shiniest brass which is sourced locally. This will increase the longevity of your purchase.</p>
</div>
</section>
<section id="how-it-works">
<video id="video">
<source src="https://youtu.be/y8Yv4pnO7qc" />
</video>
</section>
<section id="pricing">
<div class="tenor">
<h2>TENOR TROMBONE</h2>
₦600
<ul>Lorem ipsum.</ul>
<ul>Lorem ipsum.</ul>
</div>
<input type="submit" value="SELECT" />
</section>
</main>
</body>
</html>
/* file: styles.css */
**Your browser information:**
User Agent is: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/103.0.0.0 Safari/537.36
Challenge: Product Landing Page - Build a Product Landing Page
Link to the challenge: