JSFiddle - React, Tailwind, and code Playground

HTML

<header>
  Fixed Header.
</header>

<form>
  <input type="text" required />
  <br />
  <input type="date" required />
  <br />
  <input type="submit">
</form>

CSS

html {
  scroll-padding-top: 70px;
}

body {
  max-width: 500px;
  font-family: Roboto, sans-serif;
  line-height: 1.4;
  margin: 0 auto;
  padding: 4rem 1rem;
  font-size: 1.5rem;
}

header {
  position: fixed;
  top: 0;
  left: 0;
  text-align: center;
  color: white;
  width: 100%;
  padding: 1rem;
  background: #1976D2;
}

input[type=submit] {
  margin-top: 500px;
}