listed-theme.css

/* Import the font */
@import url('https://fonts.googleapis.com/css2?family=Open+Sans&display=swap');

/* Declare the font family */
.h1,
.h2,
.h3,
.h4,
.h5 {
font-family: 'JetBrains Mono', serif;
}
body {
font-family: 'JetBrains Mono','Open Sans', Roboto, sans-serif;
}