* {
  box-sizing: border-box;
}

body {
  font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
  padding: 10px;
  background: #f1f1f1;
}

.header {
  padding: 30px;
  text-align: center;
  background: #1abc9c;
}

.header h1 {
  font-size: 50px;
}


.topnav {
  overflow: hidden;
  background-color: #666;
}

.topnav a {
  float: left;
  display: block;
  color: #f2f2f2;
  text-align: center;
  padding: 14px 16px;
  text-decoration: none;
}

.topnav a:hover {
  background-color: #ddd;
  color: black;
}

.leftcolumn {   
  float: left;
  width: 75%;
}

.rightcolumn {
  float: left;
  width: 25%;
  background-color: #f1f1f1;
  padding-left: 20px;
}

.fakeimg {
  background-color: #aaa;
  width: 100%;
  padding: 20px;
}

.card {
  background-color: white;
  padding: 20px;
  margin-top: 20px;
}

.row:after {
  content: "";
  display: table;
  clear: both;
}

.footer {
  padding: 20px;
  text-align: center;
  background: #ddd;
  margin-top: 20px;
}

.active {
  background-color: #31a3f5;
}

@media screen and (max-width: 800px) {
  .leftcolumn, .rightcolumn {   
    width: 100%;
    padding: 0;
  }
}

@media screen and (max-width: 400px) {
  .topnav a {
    float: none;
    width: 100%;
  }

  .badge {
    background-color: red;
    color: white;
    padding: 4px 8px;
    text-align: center;
    border-radius: 5px;
  }
}