Reply To: Curve the corners (header top / footer bottom) ? + Add transparent borders ?

For the third question : it’s ok ! I find :

.header {
margin: 15px auto;
padding: 0px 0px;
border-top: 0px solid rgba(0,0,0,.1);
}

And it’s perfect so if you could just answer me for the first question (make round the corner) ? thanks