<form>
  <label for="url">Enter an https:// URL:</label>
  <input type="url" name="url" id="url" placeholder="https://example.com" pattern="https://.*" size="30" required />
</form>

label {
  display: block;
  font:
    1rem 'Fira Sans',
    sans-serif;
}

input,
label {
  margin: 0.4rem 0;
}