body {
  font-family: Sans-Serif;
  padding: 0;
  margin: 0;
}
.card {
   box-shadow: 0 4px 8px 0 rgba(0, 0, 0, 0.2);
   border-radius: 5px;
   padding: 20px;
   margin-top: 20px;
}
header {
  display: inline;
}
nav li {
   display: inline;
   list-style-type: none;
   margin-right: 20px;
}
nav {
  text-align: right;
   background-color: red;
   margin: 2px;
   padding: 5px;
}
nav a {
   font-size: 10px;
   font-weight: 400;
   text-decoration: none;
   color: white;
}
nav a:hover {
   font-weight: bold;
   color: blue;
}

main {
  display: inline;
}
.container {
position: relative;
padding: 2px;
margin: 2px;
border: 4px solid red;
}
img {
  width: 100%;
}
@media screen and (min-width: 450px) {
   .light_blue, .green {
       width: 50%
   }
}
footer {
  font-size: 10px;
  text-align: center;
   padding: 2px;
   margin: 2px;
   color: white;
   background-color: red;
}