h1 {text-align: center;}
  p {text-align: center;}
  div {text-align: center;}

body {
  margin: 0;
  font-family: Arial, Helvetica, sans-serif;
}

.topnav {
  overflow: hidden;
  background-color: #333;
}

.topnav a {
  float: left;
  color: #f2f2f2;
  text-align: center;
  padding: 14px 16px;
  text-decoration: none;
  font-size: 17px;
}

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

.topnav a.active {
  background-color: #4CAF50;
  color: white;
}

.topnav .search-container {
  float: right;
}

.topnav input[type=text] {
  padding: 6px;
  margin-top: 8px;
  font-size: 17px;
  border: none;
}

.topnav .search-container button {
  float: right;
  padding: 6px;
  margin-top: 8px;
  margin-right: 16px;
  background: #ddd;
  font-size: 17px;
  border: none;
  cursor: pointer;
}

.topnav .search-container button:hover {
  background: #ccc;
}

@media screen and (max-width: 600px) {
  .topnav .search-container {
    float: none;
  }
  .topnav a, .topnav input[type=text], .topnav .search-container button {
    float: none;
    display: block;
    text-align: left;
    width: 100%;
    margin: 0;
    padding: 14px;
  }
  .topnav input[type=text] {
    border: 1px solid #ccc;  
  }


img {
  max-width: 100%;
  height: auto;
}

a:link, a:visited {
  background-color: black;
  color: white;
  padding: 14px 25px;
  text-align: center;
  text-decoration: none;
  display: inline-block;
}

a:hover, a:active {
  background-color: red;
}