A very simple css for html without additional classes or ids
See Demo
Just add
<meta name="viewport" content="width=device-width, initial-scale=1.0" />
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
<link rel="stylesheet" href="./style.css" />
<link rel="preconnect" href="https://fonts.googleapis.com" />
<link rel="preconnect" href="https://fonts.gstatic.com" crossorigin />
<link
href="https://fonts.googleapis.com/css2?family=M+PLUS+1p:wght@400;700&display=swap"
rel="stylesheet"
/>in the <head> tag.
See index.html for more detailed information.