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

header{
    background-color: rgb(63, 139, 165);
    padding-top: 25px;
    height: 55px;
    margin-top: 5px;
    margin-left: 20%;
    margin-right: 20%;
    border-radius: 30%;
    display: flex;
    justify-content: space-evenly;
}

ul{
    text-align: center;
}

li{
    text-align: center;
    display: inline;
    margin: auto 10px;
}

li > a {
    text-decoration: none;
    color: rgb(255, 255, 255);
    font-size: 19px;
}

li > a:hover {
    color: rgb(30, 209, 162);
}

@media screen and (max-width: 425px) {
    header{ 
        height: 145px;
    }

    li {
        display: flex;
        flex-direction: column;
    }

    li > a{
        font-size: 25px;
    }
}