.flex-container {
display: -webkit-flex;
display: flex;  
-webkit-flex-flow: row wrap;
flex-flow: row wrap;
text-align: center;
}

.flex-container > * {
padding: 15px;
-webkit-flex: 1 100%;
flex: 1 100%;
}

.article {
text-align: left;
}


header {background:#000000;color:#FFFFFF;}
footer {background: #aaa;color:#FFFFFF;;}
.nav {background:#eee;}

.nav ul {
list-style-type: none;
padding: 0;
}
.nav ul a {
text-decoration: none;
}

p.serif {
font-family: "Times New Roman", sans-serif;
}