<div class="outer-div"><div class="inner-div"></div></div>

body
{
  padding: 30px;
  background-color: #fcfcfc;  
}
.outer-div
{
  padding: 30px;
  background-color: #f3f3f3;
}
.inner-div
{
  margin: 0 auto;
  max-width: 700px;
  height: 100px;
  background-color: #ccc;
  border-radius: 3px;
}