body{
    font-family: Arial, Helvetica, sans-serif;
}

header{
Display: flex;
background-color: lightpink;
height; 2rem;
line-height: 2rem;
color: lightyellow;
border-bottom: 5px solid yellow;
}
h1 {
   .libertinus-serif-display-regular {
  font-family: "Libertinus Serif Display", system-ui;
  font-weight: 400;
  font-style: normal;
  }
}