I use this simple snippet for styles in the root index.css for most React projects as a default start point:
* {
margin: 0;
padding: 0;
}
*,
*::before,
*::after {
box-sizing: inherit;
}
html {
box-sizing: border-box;
font-size: 62.5%;
}
body {
font-family: sans-serif;
font-size: 1.6rem;
line-height: 1.6;
}