body {
  font-family: Arial, sans-serif;
  margin: 0;
  padding: 0;
  background: #f4f4f4;
}
header {
  background: #333;
  color: #fff;
  padding: 10px;
  display: flex;
  justify-content: space-between;
  align-items: center;
}
main {
  display: flex;
  gap: 20px;
  padding: 20px;
}
.product {
  background: #fff;
  padding: 15px;
  border-radius: 10px;
  box-shadow: 0 2px 5px rgba(0,0,0,0.1);
  text-align: center;
  width: 200px;
}
#cart {
  position: fixed;
  top: 60px;
  right: 20px;
  background: #fff;
  padding: 15px;
  border: 1px solid #ccc;
  border-radius: 10px;
  box-shadow: 0 2px 5px rgba(0,0,0,0.2);
  width: 300px;
}
.hidden { display: none; }
button {
  background: #28a745;
  color: #fff;
  border: none;
  padding: 10px;
  border-radius: 5px;
  cursor: pointer;
}
button:hover {
  background: #218838;
}