body {
  margin: 0;
  font-family: system-ui;
  background: linear-gradient(180deg,#f1f5ff,#ffffff);
  color: #0f172a;
}

.nav {
  display: flex;
  justify-content: space-between;
  padding: 1rem 2rem;
  background: white;
  position: sticky;
  top: 0;
  z-index: 100;
  box-shadow: 0 10px 25px rgba(0,0,0,0.05);
}

.nav-links a {
  margin-right: 1rem;
  text-decoration: none;
  font-weight: 600;
  color: #1e293b;
}

.cart-btn {
  background: none;
  border: none;
  font-size: 1.3rem;
  cursor: pointer;
}

.hero {
  padding: 5rem 1rem;
  text-align: center;
  background: linear-gradient(135deg,#2563eb,#1e40af);
  color: white;
}

section {
  padding: 4rem 1rem;
  text-align: center;
}

.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit,minmax(250px,1fr));
  gap: 2rem;
  max-width: 1000px;
  margin: auto;
}

.card {
  background: #ffffff;
  border-radius: 16px;
  padding: 2rem;
  box-shadow: 0 20px 35px rgba(0,0,0,0.08);
}

.card.clickable {
  cursor: pointer;
  border: 2px solid #22c55e;
}

.price {
  font-size: 1.5rem;
  font-weight: 800;
  color: #2563eb;
}

.product-grid {
  display: flex;
  justify-content: center;
  gap: 1rem;
  flex-wrap: wrap;
}

.product-grid button {
  padding: 1rem 1.5rem;
  border-radius: 12px;
  border: none;
  background: #2563eb;
  color: white;
  font-weight: 700;
  cursor: pointer;
}

/* CART */
.cart {
  position: fixed;
  right: 20px;
  top: 80px;
  width: 300px;
  background: white;
  padding: 1.5rem;
  border-radius: 16px;
  box-shadow: 0 30px 50px rgba(0,0,0,0.15);
}

.hidden {
  display: none;
}

.checkout-btn {
  width: 100%;
  padding: 0.8rem;
  background: #22c55e;
  border: none;
  border-radius: 10px;
  font-weight: 800;
}