.card {
  box-shadow: 0 4px 8px 0 rgba(0, 0, 0, 0.2);
  max-width: 300px;
  margin: auto;
  text-align: center;
  font-family: arial;
  margin: 15px;
  float: left;
}
.price {
  color: grey;
  font-size: 22px;
}

.stock {
  border: none;
  outline: 0;
  padding: 12px;
  color: white;
  background-color: #000;
  text-align: center;
  width: 92%;
  font-size: 18px;
}

.row {
  box-shadow: 0 4px 8px 0 rgba(0, 0, 0, 0.2);
  max-width: 100%;
  margin: auto;
  text-align: center;
  font-family: arial;
  margin: 15px;
  float: left;
  text-align: center;
}

hr {
  clear: both;
}

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

.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;
}