:root {
  --bg-color: #f7f8fa;
  --text-color: #333;
  --card-bg: #fafafa;
  --btn-bg: #28a745;
  --btn-hover: #218838;
}

body.dark-mode {
  --bg-color: #1e1e2f;
  --text-color: #f0f0f0;
  --card-bg: #2a2a40;
  --btn-bg: #0069d9;
  --btn-hover: #0053aa;
}

body {
  margin: 0;
  font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
  background-color: var(--bg-color);
  color: var(--text-color);
  transition: background-color 0.5s, color 0.5s;
}

header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 20px;
  background-color: #ffffff10;
  backdrop-filter: blur(6px);
  position: sticky;
  top: 0;
  z-index: 100;
  border-bottom: 1px solid #ddd;
}

.logo {
  height: 40px;
  width: 40px;
  margin-right: 10px;
}

h1 {
  font-size: 1.8em;
  color: var(--text-color);
  flex: 1;
}

#theme-toggle, .cart-toggle-btn {
  background: none;
  border: none;
  font-size: 1.4em;
  cursor: pointer;
  margin-left: 15px;
}

.container {
  max-width: 1000px;
  margin: 30px auto;
  padding: 20px;
}

.product-list {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 20px;
}

.product-card {
  background: var(--card-bg);
  padding: 15px;
  border-radius: 10px;
  text-align: center;
  transition: transform 0.2s ease-in-out;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.08);
}

.product-card:hover {
  transform: translateY(-5px);
}

.product-card img {
  width: 100%;
  height: 150px;
  object-fit: contain;
  margin-bottom: 10px;
}

.product-card h3 {
  font-size: 18px;
}

.product-card p {
  font-size: 16px;
  margin: 5px 0;
}

.product-card button {
  background-color: var(--btn-bg);
  border: none;
  color: #fff;
  padding: 10px 16px;
  border-radius: 8px;
  cursor: pointer;
  transition: background 0.2s ease;
}

.product-card button:hover {
  background-color: var(--btn-hover);
}

.cart-section {
  margin-top: 40px;
  padding: 20px;
  background: var(--card-bg);
  border-radius: 12px;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.08);
}

.cart-items {
  margin-top: 10px;
  padding: 10px;
}

.cart-item {
  display: flex;
  justify-content: space-between;
  padding: 10px 0;
  border-bottom: 1px solid #ccc;
}

#cart-total {
  margin-top: 20px;
  text-align: center;
}

#checkout-btn {
  background-color: var(--btn-bg);
  padding: 10px 20px;
  border: none;
  border-radius: 8px;
  color: white;
  font-size: 16px;
  cursor: pointer;
}

#checkout-btn:hover {
  background-color: var(--btn-hover);
}

#empty-cart {
  text-align: center;
  color: #888;
}

.hidden {
  display: none;
}