@media screen and (min-width: 480px) {
  
  /***************************
  TWO COLUMN LAYOUT
  ***************************/
  
  #primary {
    width: 50%;
    float: left;
  }
  
  #secondary {
    width:40%;
    float: right;      
  }
  
  
  /***************************
  PAGE: PORTFOLIO
  ***************************/
  
  #gallery li {
    width: 28.3333%;
  }
  
  #gallery li:nth-child(4n) {
    clear: left;
  }
  
  
  /***************************
  PAGE: ABOUT
  ***************************/
  
  .profile-photo {
    float: left;
    margin: 0 5% 80px 0;
  }
  
}

@media screen and (min-width: 660px) {
  
  /***************************
  HEADER
  ***************************/
  
  nav {
    font-size: 1.125em;
  }
  
  h1 {
    font-size: 2.5em;
  }
  
  h2 {
    font-size: 1em;
    margin-bottom: 20px;
  }
  
}