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

.main-nav{
    margin-top: 10px;
    list-style: none;
    padding-left: 0;
    background-color: #13a4a4;
}

.main-nav-items {
    display: inline-block;
    border-right: 2px solid #fff;
}

.main-nav-items a{
    color: white;
    padding: 2px 8px;
    text-decoration: none;
}

.main-nav-items a:hover{
    color: blue;
}

.main-nav-items a:active{
    color: red;
}

main{
    width: 100%;
    height: 300px;
    border: 10px solid gray;
    padding: 20px 35px;
}