*{
    margin:0;
}
body{
    margin-left: auto;
    margin-right: auto;
    width:100%;
    max-width: 1300px;
}
header > nav{
    display:flex;
    justify-content: space-between;
    align-items: center;
    width:100%;

}
header > nav > ul{
    display:inline-block;
}
header > nav > ul > a{
    margin-left:4px;
}
header > nav > ul > a > li{
    display:inline-block;
}
main{
    display:flex;
    justify-content:flex-start;
    align-items:flex-start;
    width:100%;
    max-width:1300px;
    /* flex-direction: column; */
}
article{
    width:100%;
    max-width:1300px;
    font-size:20px;
}
aside{
    position:sticky;
    top:0;
    width:100%;
    max-width:300px;
    height:300px;
    background-color: green;
    display:flex;
    justify-content: center;
    align-items: center;
}