html, body {
    margin: 0;
    padding: 0;
    font-family: Arial, sans-serif;
}
body{
    display: flex;
    padding: 20px;
    flex-direction: row-reverse;
    justify-content: space-evenly;

    background-image: linear-gradient(to right, white, blue, yellow);
    header{
        ul{
            list-style-type: none;
            >li{
                margin: 10px 0;
                >a{
                    color: black;
                    &:hover{
                        padding: 5px;
                        background-color: navy;
                        color: white;
                        border: 2px solid gold;
                        border-radius: 10px;
                        text-decoration: none;
                    }
                }
            }
        }
    }
    main>iframe{
        border: 3px dotted black;
        margin: 25px;
    }
}