How to add new line in html between h1 and h2-CodePudding

I'm new to HTML and I am trying to add a new line between h1 and h2, here is the code

@font-face {
  font-family: 'mainFont';
  src: url("Fonts/Poppins/Poppins-Medium.ttf") format('truetype');
}

body {
  height: 90vh;
  display: flex;
  align-items: center;
  text-align: center;
  justify-content: center;
  background: #f8f8f8;
  position: fixed;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
}

.main {
  font-family: 'mainFont';
  font-weight: normal;
  font-style: normal;
  font-size: 60px;
  color: #181818;
}

.subMain {
  font-family: 'mainFont';
  font-weight: normal;
  font-style: normal;
  font-size: 45px;
  color: #181818;
}

<!DOCTYPE html>
<html lang='en'>

<head>
  <link rel='stylesheet' href='style.css'>
</head>

<body>
  <h1 class='main'>Hello World