Responsive spacing between navbar and content css - html

Question

In a website I'm making with bootstrap, I need responsive spacing between the navbar( bootstrap ) and the content, in this case, a form as shown in the snippet below.
.curved-div svg {
position: absolute;
transform: scale(1, -1);
display: block;
z-index: -1;
}
.navbar-light .navbar-nav .nav-link {
color: white;
z-index: 2;
}
.curved-div {
height: 30vh;
}
<script src="https://cdn.jsdelivr.net/npm/bootstrap#5.1.3/dist/js/bootstrap.bundle.min.js"></script>
<link href="https://cdn.jsdelivr.net/npm/bootstrap#5.1.3/dist/css/bootstrap.min.css" rel="stylesheet" integrity="sha384-1BmE4kWBq78iYhFldvKuhfTAU6auU8tT94WrHftjDbrCEXSU1oBoqyl2QvZ6jIW3" crossorigin="anonymous">
<div class="curved-div">
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 1440 320">
<path fill="#0099ff" fill-opacity="1"
d="M0,224L48,197.3C96,171,192,117,288,117.3C384,117,480,171,576,208C672,245,768,267,864,250.7C960,235,1056,181,1152,160C1248,139,1344,149,1392,154.7L1440,160L1440,320L1392,320C1344,320,1248,320,1152,320C1056,320,960,320,864,320C768,320,672,320,576,320C480,320,384,320,288,320C192,320,96,320,48,320L0,320Z">
</path>
</svg>
<nav class="navbar navbar-expand-lg navbar-light sticky-top">
<div class="container">
My site
<button class="navbar-toggler" type="button" data-bs-toggle="collapse" data-bs-target="#navbarSupportedContent" aria-controls="navbarSupportedContent" aria-expanded="false" aria-label="Toggle navigation">
<span class="navbar-toggler-icon"></span>
</button>
<div class="collapse navbar-collapse" id="navbarSupportedContent">
<ul class="navbar-nav ms-auto mb-2 mb-lg-0">
<li class="nav-item">
<a class="nav-link" aria-current="page" href="/">Home</a>
</li>
<li class="nav-item">
<a class="nav-link " href="/games">All blogs</a>
</li>
<li class="nav-item">
<a class="nav-link " href="/contactus">Contact us</a>
</li>
Login
Register
</ul>
</div>
</ul>
</div>
</div>
</nav>
</div>
<form>
<input type="text" name="username" placeholder="Username"> <br><br>
<input type="password" name="password" placeholder="Password" id="password" oninput="passwordInput()" maxlength="255"> <br><br>
<input type="password" name="password2" placeholder="Retype password" id="password2" oninput="passwordInput()" maxlength="255"> <br><br>
<input type="email" name="email" placeholder="Email( We will not spam )" maxlength="321"><br><br>
<button type="submit" value="Submit" id="submit"> Submit </button> <span id="error"></span>
</form>
But the spacing between the navbar and form varies on all devices, and I want the content to always be out of the navbar's styling. I tried setting the height of .curved-div to percentage( % ) and viewport height ( vh ) but on emulating it in the chrome dev tools, neither worked and both gave the same output of not being responsive. Any help is greatly appreciated. Thanks!