@charset "UTF-8"; 

body {
  background-color: rgb(102, 171, 255);
}
 
#wrap {
  width: 960px;
  margin: auto;
  background-color: white;
}
 
header   {
  padding: 40px;
  height: 80px;
}
 
nav {
  padding: 8px 40px;
  background-color: black;
  color: white;
  transition-property: background-color;
  transition-duration: .3s;
}
nav:hover {
  background-color: dimgray;
}
main{
  padding: 40px;
  height : 400px;
  .expansion {
    width: 500px;
    height: 300px;
    overflow: hidden;
  }
  .expansion img {
    width: 100%;
    transition: transform .5s;
  }
  
  .expansion img:hover {
    transform: scale(1.1);
  }
  
}
 
footer   {
  padding: 40px;
  height: 40px;
  background-color : black;
  color: white;
}