body {
    margin:0;
    padding:0;
}
section, header, footer {
    max-width:1000px;
    margin:0 auto;
    border-left: 1px solid grey;
    border-right:1px solid grey;
}
header h1, footer h1 {
    text-shadow:1px 0 grey, -1px 0 grey, 0 1px grey, 0 -1px grey;
}
header {
    text-align:center;
    position:relative;
    border-bottom:1px solid grey;
    border-top:1px solid grey;
    background:lightblue;
    padding-top:1em;
    padding-bottom:1em;
}
header h1 {
    margin:0;
    padding:0;
}
section {   
    display:flex;
}
section h1 {
    margin-top:0;
}
section ul {
    margin:0;
}
nav, article {
    padding:8px;
}
article img {
    border-radius:8px;
    box-shadow:4px 4px 8px black;
    border:1px solid white;
}
nav {
    flex: 1 100%;
    background:lightgreen;
    border-right:1px solid grey;
}
article {
    flex:1 300%;
}
footer {
    border-top: 1px solid grey;
    text-align:center;
    border-bottom:1px solid grey;
    background: salmon;
}
a {
    color:blue;
}