h1
{
    color: black;
    margin: auto;
    text-align: center;
}

.main-head
{
    background-color: yellow;
}

.btn
{
    height: 100px;
    width: 100px;
    border-radius: 50%;
    display: flex;
    justify-content: center;
    align-items: center;
    position: fixed;
    right: 20px;
    bottom: 20px;
}

a
{
    color: black;
}

a:hover
{
    color: white;
}

a:visited
{
    color: black;
}

ul
{
    display: block;
    list-style-type: disc;
    margin-block-start: 1em;
    margin-block-end: 1em;
    margin-inline-start: 0px;
    margin-inline-end: 0px;
    padding-inline-start: 40px;
}

body
{
    align-items: center;
}

nav ul 
{
    display: flex;
    flex: 1 1 40rem;
    justify-content: space-around;
    align-items: center;
    list-style: none;
}

img.icone
{
    height: 70px;
}