<head>
<style>
html, body {
- height:100%;
- width:100%;
background: #f1f1f1;
}
#loginForm {
display: flex;
flex-direction: column;
- height: 100%;
text-align: center;
align-items: center;
}
<input type='button' value='Submit' id='submit'>
</form>
</body>
-</html>
\ No newline at end of file
+</html>