responsive.css

@media (max-width: 600px) {
  #container{
    width: 100%;
  }
  #container header{
    margin: 10px 30px;
  }
  #container header nav{
    width: 100%;
  }

  #container #main{
    background-color: #fff;
    width: 80%;
    margin: 0 10%;
  }

  #container #main h2{
    font-size: 30px;
    font-weight: bold;
  }

  #main h2 a{ color: red; }
  #main article h3{
    font-size: 24px;
    color: green;
  }

  .sidebar {
    display: none;
  }
}