main.css

/* general settings */

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    min-height: 100vh;
    width: 100%;
}

/* lessons nav bar */

#container {
    border-radius: 10px;
    background-color: lightgray;
    padding: 25px;
    display: flex;
    flex-direction: row;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    margin-bottom: 20px;
    font-family: Arial, Helvetica, sans-serif;
}

#container h2 {
    flex-wrap: wrap;
    display: flex;
    text-align: left;
    font-size: 2em;
    flex-grow: 1;
    padding-bottom: 12px;
}

#container nav {
    flex-wrap: wrap;
    display: flex;
    justify-content: space-around;
    flex-grow: 2;
    gap: 12px;
}

#container a {
    color: #181818;
    text-decoration: none;
    padding: 0px 10px;
}

#container a:hover {
    color: white;
    background-color: #181818;
}

#container a:focus {
    color: orange;
    background-color: #181818;
}

a {
    text-decoration: none;
    color: orange;
}
/* media query lessons nav bar */

@media (max-width: 576px) {
    #container {
        display: flex;
        flex-wrap: wrap;
        flex-direction: column;
        align-content: flex-start;
        align-items: flex-start;
    }

    #container nav {
        display: flex;
        flex-direction: column;
        margin-top: 1.5em;
        line-height: 2.5rem;
    }

    #container a:focus {
        font-size: 1rem;
        line-height: 2rem;
        background-color: #181818;
        color: white;
    }
}