body {
  font-family: Arial, sans-serif;
  margin: 0;
  padding: 0;
  background: #f4f4f4;
}

header {
  background: #0a3d62;
  color: white;
  padding: 20px;
  text-align: center;
}

nav {
  background: #1e3799;
  padding: 10px 0;
  text-align: center;
}

nav ul {
  list-style: none;
  margin: 0;
  padding: 0;
}

nav ul li {
  display: inline;
  margin: 0 15px;
}

nav ul li a {
  color: white;
  text-decoration: none;
  font-weight: bold;
}

main {
  padding: 20px;
}

.product-grid {
  display: flex;
  gap: 20px;
  flex-wrap: wrap;
  justify-content: center;
}

.product-card {
  background: white;
  padding: 15px;
  border-radius: 5px;
  box-shadow: 0 2px 5px rgba(0,0,0,0.1);
  width: 200px;
  text-align: center;
}

.product-card img {
  width: 100%;
  height: auto;
  border-radius: 5px;
}

button {
  background-color: #1e90ff;
  color: white;
  border: none;
  padding: 10px;
  margin-top: 10px;
  cursor: pointer;
  border-radius: 5px;
}

button:hover {
  background-color: #0066cc;
}

#cart {
  margin-top: 30px;
  background: #fff;
  padding: 20px;
  border-radius: 5px;
}

footer {
  background: #0a3d62;
  color: white;
  text-align: center;
  padding: 15px;
  margin-top: 40px;
}

#checkout-btn {
  margin-top: 15px;
  background-color: #5787df;
  color: white;
  padding: 10px 15px;
  font-size: 16px;
}

#checkout-btn:hover {
  background-color: #1ebe57;
}