body{
    background-color: silver;
    width: 960px;
    margin: auto;
    border: 1px dotted black;
}

ol{
    list-style-type: none;
    display: flex;
    flex-direction: row;
    justify-content: center;
}

a{
    display: block;
    width: 150px;
    padding-top: 1em;
    padding-bottom: 1em;
    background-color: navy;
    color: silver;
    text-align: center;
    text-decoration: none;
    margin-right: 5px;
    border-radius: 10px;
}

a.last{
    margin-right: 0px;
}

a:hover{
    background-color: orange;
    color: navy;
}