* {
	margin: 0; padding: 0; border: none; 
	box-sizing: border-box;
}


    body {
      background-color: #ccc;
    }
    
    ul {
      list-style: none;
      
    }
    
    nav {
        width: 25%;
        margin: 10px;
    }
    nav ul {
    }
      nav ul li {        
        height: 30px;
        text-align: center;
      }
      nav ul li a {
        display: block;
        text-decoration: none;
        padding-left: 30px;
        padding-right: 30px;
        line-height: 30px;
        background-color: #222;
        color: #ccc;
        border-radius: 20px;
      }
        nav ul li a:hover {
          background-color: #eee;
        }
    
    .pic-cont {
      float: left;
      padding: 1%;
    }
    .pic-cont a {
      display: block;
    }
    .pic-cont a img {
      width: 100%;
    }
    
    #menu-qual {
      clear: both;
      width: 25%;
    }
    #menu-qual ul li {
      float: left;
      width: 33%;
      text-align: center;
      padding: 0.5%;
    }
    
    video {
      clear: both;
    }
    
@media only screen and (min-width: 641px) {
  .pic-cont {
    width: 12.5%;
  }
  .pic-cont:nth-of-type(8n+1) {
    clear: both;
  }
    div > video {
      width: 50%;
    }
}

@media only screen and (min-width: 321px) and (max-width: 640px) {
  .pic-cont {
    width: 25%;
  }
    .pic-cont:nth-of-type(4n+1) {
      clear: both;
    }
    
    div > video {
      width: 100%;
    }
}

@media only screen and (max-width: 320px) {
  .pic-cont {
    width: 50%;
  }
    .pic-cont:nth-of-type(2n+1) {
      clear: both;
    }
    div > video {
      width: 100%;
    }
}