header nav {
display: flex;
flex-wrap: wrap;
justify-content: center;
}

header nav a {
text-decoration: none;
border: 2px solid var(--border-color);
border-radius: 5px;
margin: 7px;
padding: 5px;
}

header nav a:hover {
background-color: var(--light-bg-color);
text-decoration: none;
}