/* ============ 全局重置 ============ */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html, body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', sans-serif;
  color: #333;
  background: #f5f7fa;
  line-height: 1.6;
  min-height: 100vh;
}

a {
  text-decoration: none;
  color: inherit;
}

ul, li {
  list-style: none;
}

img {
  max-width: 100%;
  height: auto;
}

button {
  cursor: pointer;
  border: none;
  outline: none;
  font-family: inherit;
}

/* ============ 顶部导航 ============ */
.header {
  background: linear-gradient(135deg, #1a2a6c 0%, #2d4a9e 50%, #00a8ff 100%);
  color: #fff;
  position: sticky;
  top: 0;
  z-index: 1000;
  box-shadow: 0 2px 20px rgba(0, 0, 0, 0.15);
}

.header-top {
  background: rgba(0, 0, 0, 0.2);
  font-size: 13px;
  padding: 6px 0;
}

.header-top .container {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.header-top a {
  margin-left: 20px;
  opacity: 0.9;
  transition: opacity 0.3s;
}

.header-top a:hover {
  opacity: 1;
  text-decoration: underline;
}

.header-main {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 15px 0;
}

.logo {
  font-size: 24px;
  font-weight: bold;
  display: flex;
  align-items: center;
  gap: 10px;
}

.logo-icon {
  width: 40px;
  height: 40px;
  background: linear-gradient(135deg, #00d2ff, #3a7bd5);
  border-radius: 8px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 20px;
  box-shadow: 0 4px 15px rgba(0, 168, 255, 0.4);
}

.nav-menu {
  display: flex;
  gap: 8px;
}

.nav-menu a {
  padding: 10px 20px;
  border-radius: 6px;
  transition: all 0.3s;
  font-weight: 500;
}

.nav-menu a:hover,
.nav-menu a.active {
  background: rgba(255, 255, 255, 0.2);
}

.header-actions {
  display: flex;
  gap: 15px;
  align-items: center;
}

.search-box {
  display: flex;
  background: rgba(255, 255, 255, 0.15);
  border-radius: 20px;
  overflow: hidden;
}

.search-box input {
  background: transparent;
  border: none;
  padding: 8px 15px;
  color: #fff;
  width: 200px;
  outline: none;
}

.search-box input::placeholder {
  color: rgba(255, 255, 255, 0.7);
}

.search-box button {
  background: rgba(255, 255, 255, 0.2);
  padding: 8px 15px;
  color: #fff;
}

.cart-btn {
  background: rgba(255, 255, 255, 0.15);
  padding: 8px 18px;
  border-radius: 20px;
  color: #fff;
  display: flex;
  align-items: center;
  gap: 6px;
  transition: all 0.3s;
  position: relative;
}

.cart-btn:hover {
  background: rgba(255, 255, 255, 0.3);
}

.cart-count {
  background: #ff4757;
  color: #fff;
  border-radius: 50%;
  width: 20px;
  height: 20px;
  font-size: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  position: absolute;
  top: -5px;
  right: -5px;
}

/* ============ 容器 ============ */
.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 20px;
}

/* ============ 轮播图 ============ */
.banner {
  position: relative;
  overflow: hidden;
  border-radius: 12px;
  margin-top: 20px;
  height: 400px;
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
}

.banner-slides {
  display: flex;
  transition: transform 0.5s ease;
  height: 100%;
}

.banner-slide {
  min-width: 100%;
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: center;
  color: #fff;
  position: relative;
}

.banner-slide::before {
  content: '';
  position: absolute;
  inset: 0;
  background: radial-gradient(circle at 30% 50%, rgba(255,255,255,0.1), transparent 60%);
}

.banner-content {
  text-align: center;
  z-index: 2;
  padding: 40px;
}

.banner-content h2 {
  font-size: 42px;
  margin-bottom: 15px;
  text-shadow: 0 2px 10px rgba(0,0,0,0.3);
}

.banner-content p {
  font-size: 18px;
  margin-bottom: 25px;
  opacity: 0.9;
}

.banner-btn {
  background: #fff;
  color: #1a2a6c;
  padding: 12px 35px;
  border-radius: 30px;
  font-weight: bold;
  font-size: 16px;
  transition: all 0.3s;
  display: inline-block;
}

.banner-btn:hover {
  transform: translateY(-2px);
  box-shadow: 0 10px 25px rgba(0,0,0,0.2);
}

.banner-dots {
  position: absolute;
  bottom: 20px;
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  gap: 10px;
}

.banner-dots span {
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: rgba(255,255,255,0.5);
  cursor: pointer;
  transition: all 0.3s;
}

.banner-dots span.active {
  background: #fff;
  transform: scale(1.2);
}

/* ============ 分类导航 ============ */
.category-nav {
  background: #fff;
  border-radius: 12px;
  padding: 20px 30px;
  margin-top: -40px;
  position: relative;
  z-index: 10;
  box-shadow: 0 5px 30px rgba(0,0,0,0.08);
  display: flex;
  justify-content: space-around;
}

.category-item {
  text-align: center;
  padding: 10px 20px;
  transition: all 0.3s;
  border-radius: 10px;
  cursor: pointer;
}

.category-item:hover {
  background: #f5f7fa;
  transform: translateY(-3px);
}

.category-icon {
  width: 60px;
  height: 60px;
  border-radius: 50%;
  background: linear-gradient(135deg, #e0eafc, #cfdef3);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 28px;
  margin: 0 auto 10px;
  transition: all 0.3s;
}

.category-item:hover .category-icon {
  background: linear-gradient(135deg, #00a8ff, #0066cc);
  color: #fff;
}

.category-item span {
  font-size: 14px;
  font-weight: 500;
  color: #555;
}

/* ============ 区块标题 ============ */
.section {
  margin: 40px 0;
}

.section-title {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 25px;
}

.section-title h2 {
  font-size: 24px;
  color: #1a2a6c;
  position: relative;
  padding-left: 15px;
}

.section-title h2::before {
  content: '';
  position: absolute;
  left: 0;
  top: 50%;
  transform: translateY(-50%);
  width: 4px;
  height: 24px;
  background: linear-gradient(180deg, #00a8ff, #1a2a6c);
  border-radius: 2px;
}

.section-title a {
  color: #00a8ff;
  font-size: 14px;
  transition: color 0.3s;
}

.section-title a:hover {
  color: #1a2a6c;
}

/* ============ 商品卡片 ============ */
.product-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
}

.product-card {
  background: #fff;
  border-radius: 12px;
  overflow: hidden;
  transition: all 0.3s;
  cursor: pointer;
}

.product-card:hover {
  transform: translateY(-5px);
  box-shadow: 0 15px 40px rgba(0,0,0,0.12);
}

.product-img {
  height: 200px;
  background: linear-gradient(135deg, #f5f7fa, #e4e8ec);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 60px;
  position: relative;
  overflow: hidden;
}

.product-img img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
}

.product-img-fallback {
  display: inline;
}

.product-img::after {
  content: '';
  position: absolute;
  inset: 0;
  background: linear-gradient(135deg, transparent, rgba(0,168,255,0.1));
  opacity: 0;
  transition: opacity 0.3s;
}

.product-card:hover .product-img::after {
  opacity: 1;
}

.product-tag {
  position: absolute;
  top: 10px;
  left: 10px;
  background: linear-gradient(135deg, #ff4757, #ff6b81);
  color: #fff;
  padding: 4px 10px;
  border-radius: 4px;
  font-size: 12px;
  z-index: 2;
}

.product-info {
  padding: 15px;
}

.product-name {
  font-size: 15px;
  font-weight: 600;
  margin-bottom: 8px;
  color: #333;
  height: 44px;
  overflow: hidden;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
}

.product-desc {
  font-size: 12px;
  color: #888;
  margin-bottom: 10px;
  height: 32px;
  overflow: hidden;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
}

.product-bottom {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.product-price {
  color: #ff4757;
  font-size: 20px;
  font-weight: bold;
}

.product-price small {
  font-size: 12px;
  font-weight: normal;
}

.add-cart-btn {
  background: linear-gradient(135deg, #00a8ff, #0066cc);
  color: #fff;
  padding: 6px 14px;
  border-radius: 20px;
  font-size: 12px;
  transition: all 0.3s;
}

.add-cart-btn:hover {
  background: linear-gradient(135deg, #0066cc, #004499);
  transform: scale(1.05);
}

/* ============ 特色服务 ============ */
.features {
  background: #fff;
  border-radius: 12px;
  padding: 30px;
  margin: 40px 0;
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
}

.feature-item {
  text-align: center;
  padding: 20px;
  border-radius: 10px;
  transition: all 0.3s;
}

.feature-item:hover {
  background: #f5f7fa;
}

.feature-icon {
  font-size: 36px;
  margin-bottom: 12px;
}

.feature-item h4 {
  font-size: 15px;
  color: #1a2a6c;
  margin-bottom: 5px;
}

.feature-item p {
  font-size: 12px;
  color: #888;
}

/* ============ 页脚 ============ */
.footer {
  background: #1a2a6c;
  color: rgba(255,255,255,0.8);
  padding: 50px 0 20px;
  margin-top: 60px;
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 40px;
  margin-bottom: 40px;
}

.footer-col h4 {
  color: #fff;
  font-size: 16px;
  margin-bottom: 20px;
}

.footer-col p {
  font-size: 13px;
  line-height: 1.8;
  margin-bottom: 10px;
}

.footer-col a {
  display: block;
  font-size: 13px;
  padding: 5px 0;
  transition: color 0.3s;
}

.footer-col a:hover {
  color: #00a8ff;
}

.footer-bottom {
  border-top: 1px solid rgba(255,255,255,0.1);
  padding-top: 20px;
  text-align: center;
  font-size: 12px;
  color: rgba(255,255,255,0.5);
}

.footer-bottom a {
  color: rgba(255,255,255,0.7);
  text-decoration: none;
  transition: color 0.3s;
}

.footer-bottom a:hover {
  color: #00a8ff;
  text-decoration: underline;
}

/* ============ 面包屑 ============ */
.breadcrumb {
  background: #fff;
  padding: 15px 0;
  margin-bottom: 20px;
  border-radius: 8px;
}

.breadcrumb .container {
  display: flex;
  gap: 10px;
  align-items: center;
  font-size: 14px;
}

.breadcrumb a {
  color: #00a8ff;
}

.breadcrumb .current {
  color: #666;
}

/* ============ 商品列表页 ============ */
.products-page {
  display: flex;
  gap: 25px;
}

.sidebar {
  width: 220px;
  flex-shrink: 0;
}

.sidebar-box {
  background: #fff;
  border-radius: 10px;
  padding: 20px;
  margin-bottom: 20px;
}

.sidebar-box h3 {
  font-size: 16px;
  color: #1a2a6c;
  margin-bottom: 15px;
  padding-bottom: 10px;
  border-bottom: 2px solid #f5f7fa;
}

.sidebar-box li {
  padding: 8px 0;
  font-size: 14px;
  color: #555;
  cursor: pointer;
  transition: all 0.3s;
  border-bottom: 1px solid #f5f7fa;
}

.sidebar-box li:hover,
.sidebar-box li.active {
  color: #00a8ff;
  padding-left: 5px;
}

.sidebar-box li:last-child {
  border-bottom: none;
}

.main-content {
  flex: 1;
}

.sort-bar {
  background: #fff;
  border-radius: 10px;
  padding: 15px 20px;
  margin-bottom: 20px;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.sort-options {
  display: flex;
  gap: 15px;
}

.sort-options button {
  background: #f5f7fa;
  padding: 6px 15px;
  border-radius: 20px;
  font-size: 13px;
  color: #555;
  transition: all 0.3s;
}

.sort-options button.active {
  background: linear-gradient(135deg, #00a8ff, #0066cc);
  color: #fff;
}

.pagination {
  display: flex;
  justify-content: center;
  gap: 8px;
  margin-top: 30px;
}

.pagination button {
  background: #fff;
  border: 1px solid #e0e0e0;
  padding: 8px 14px;
  border-radius: 6px;
  font-size: 14px;
  color: #555;
  transition: all 0.3s;
}

.pagination button:hover,
.pagination button.active {
  background: linear-gradient(135deg, #00a8ff, #0066cc);
  color: #fff;
  border-color: transparent;
}

/* ============ 商品详情页 ============ */
.detail-page {
  background: #fff;
  border-radius: 12px;
  padding: 30px;
  margin-bottom: 30px;
}

.detail-top {
  display: grid;
  grid-template-columns: 400px 1fr;
  gap: 40px;
}

.detail-img {
  height: 400px;
  background: linear-gradient(135deg, #f5f7fa, #e4e8ec);
  border-radius: 10px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 120px;
}

.detail-info h1 {
  font-size: 24px;
  color: #333;
  margin-bottom: 15px;
}

.detail-desc {
  font-size: 14px;
  color: #666;
  line-height: 1.8;
  margin-bottom: 20px;
}

.detail-price-box {
  background: #fff5f5;
  border-radius: 10px;
  padding: 20px;
  margin-bottom: 25px;
}

.detail-price {
  color: #ff4757;
  font-size: 32px;
  font-weight: bold;
}

.detail-price small {
  font-size: 14px;
}

.detail-original-price {
  color: #999;
  font-size: 14px;
  text-decoration: line-through;
  margin-left: 15px;
}

.detail-row {
  display: flex;
  align-items: center;
  margin-bottom: 15px;
  font-size: 14px;
}

.detail-row .label {
  color: #999;
  width: 80px;
  flex-shrink: 0;
}

.spec-options {
  display: flex;
  gap: 10px;
}

.spec-options button {
  background: #f5f7fa;
  padding: 8px 18px;
  border-radius: 6px;
  font-size: 13px;
  color: #555;
  border: 1px solid transparent;
  transition: all 0.3s;
}

.spec-options button:hover,
.spec-options button.active {
  background: #fff;
  border-color: #00a8ff;
  color: #00a8ff;
}

.quantity-control {
  display: flex;
  align-items: center;
  border: 1px solid #e0e0e0;
  border-radius: 6px;
  overflow: hidden;
}

.quantity-control button {
  background: #f5f7fa;
  padding: 8px 16px;
  font-size: 16px;
  color: #555;
}

.quantity-control input {
  width: 50px;
  text-align: center;
  border: none;
  border-left: 1px solid #e0e0e0;
  border-right: 1px solid #e0e0e0;
  padding: 8px;
  font-size: 14px;
  outline: none;
}

.detail-actions {
  display: flex;
  gap: 15px;
  margin-top: 30px;
}

.btn-cart, .btn-buy {
  padding: 12px 35px;
  border-radius: 30px;
  font-size: 15px;
  font-weight: bold;
  transition: all 0.3s;
}

.btn-cart {
  background: #fff;
  color: #00a8ff;
  border: 2px solid #00a8ff;
}

.btn-cart:hover {
  background: #e8f4ff;
}

.btn-buy {
  background: linear-gradient(135deg, #ff4757, #ff6b81);
  color: #fff;
}

.btn-buy:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 20px rgba(255, 71, 87, 0.4);
}

/* 商品详情标签页 */
.detail-tabs {
  display: flex;
  gap: 0;
  border-bottom: 2px solid #f0f0f0;
  margin-bottom: 25px;
}

.detail-tabs button {
  padding: 12px 30px;
  background: transparent;
  font-size: 15px;
  color: #666;
  border-bottom: 2px solid transparent;
  margin-bottom: -2px;
  transition: all 0.3s;
}

.detail-tabs button.active {
  color: #00a8ff;
  border-bottom-color: #00a8ff;
  font-weight: 600;
}

.tab-content {
  font-size: 14px;
  color: #555;
  line-height: 2;
}

/* ============ 购物车 ============ */
.cart-page {
  background: #fff;
  border-radius: 12px;
  padding: 30px;
}

.cart-empty {
  text-align: center;
  padding: 80px 20px;
}

.cart-empty-icon {
  font-size: 80px;
  margin-bottom: 20px;
  opacity: 0.5;
}

.cart-empty p {
  color: #888;
  font-size: 16px;
  margin-bottom: 20px;
}

.cart-empty a {
  display: inline-block;
  background: linear-gradient(135deg, #00a8ff, #0066cc);
  color: #fff;
  padding: 12px 35px;
  border-radius: 30px;
  font-weight: bold;
}

.cart-table {
  width: 100%;
  border-collapse: collapse;
}

.cart-table th {
  text-align: left;
  padding: 15px;
  background: #f5f7fa;
  color: #666;
  font-weight: 600;
  font-size: 14px;
}

.cart-table td {
  padding: 20px 15px;
  border-bottom: 1px solid #f0f0f0;
  font-size: 14px;
}

.cart-product {
  display: flex;
  gap: 15px;
  align-items: center;
}

.cart-product-img {
  width: 80px;
  height: 80px;
  background: linear-gradient(135deg, #f5f7fa, #e4e8ec);
  border-radius: 8px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 32px;
  overflow: hidden;
}

.cart-product-img img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.cart-product-name {
  font-weight: 500;
  color: #333;
  margin-bottom: 5px;
}

.cart-product-spec {
  color: #999;
  font-size: 12px;
}

.cart-price {
  color: #ff4757;
  font-weight: bold;
  font-size: 16px;
}

.cart-remove {
  background: none;
  color: #999;
  font-size: 20px;
  transition: color 0.3s;
}

.cart-remove:hover {
  color: #ff4757;
}

.cart-footer {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-top: 25px;
  padding-top: 25px;
  border-top: 2px solid #f0f0f0;
}

.cart-total {
  font-size: 16px;
  color: #666;
}

.cart-total strong {
  color: #ff4757;
  font-size: 28px;
  margin-left: 10px;
}

.btn-checkout {
  background: linear-gradient(135deg, #ff4757, #ff6b81);
  color: #fff;
  padding: 14px 50px;
  border-radius: 30px;
  font-size: 16px;
  font-weight: bold;
  transition: all 0.3s;
}

.btn-checkout:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 20px rgba(255, 71, 87, 0.4);
}

/* ============ 结账页面 ============ */
.checkout-page {
  display: grid;
  grid-template-columns: 1fr 380px;
  gap: 25px;
}

.checkout-section {
  background: #fff;
  border-radius: 12px;
  padding: 30px;
  margin-bottom: 20px;
}

.checkout-section h3 {
  font-size: 18px;
  color: #1a2a6c;
  margin-bottom: 20px;
  padding-bottom: 12px;
  border-bottom: 2px solid #f5f7fa;
}

.form-group {
  margin-bottom: 18px;
}

.form-group label {
  display: block;
  font-size: 14px;
  color: #555;
  margin-bottom: 8px;
}

.form-group input,
.form-group textarea,
.form-group select {
  width: 100%;
  padding: 12px 15px;
  border: 1px solid #e0e0e0;
  border-radius: 8px;
  font-size: 14px;
  transition: border-color 0.3s;
  font-family: inherit;
}

.form-group input:focus,
.form-group textarea:focus,
.form-group select:focus {
  border-color: #00a8ff;
  outline: none;
}

.form-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 15px;
}

.payment-methods {
  display: flex;
  gap: 15px;
}

.payment-method {
  flex: 1;
  padding: 20px;
  border: 2px solid #e0e0e0;
  border-radius: 10px;
  text-align: center;
  cursor: pointer;
  transition: all 0.3s;
}

.payment-method:hover,
.payment-method.active {
  border-color: #00a8ff;
  background: #f0f8ff;
}

.payment-method-icon {
  font-size: 32px;
  margin-bottom: 10px;
}

.payment-method span {
  font-size: 14px;
  color: #555;
}

.order-summary {
  background: #fff;
  border-radius: 12px;
  padding: 30px;
  height: fit-content;
  position: sticky;
  top: 100px;
}

.order-summary h3 {
  font-size: 18px;
  color: #1a2a6c;
  margin-bottom: 20px;
}

.order-item {
  display: flex;
  justify-content: space-between;
  padding: 12px 0;
  border-bottom: 1px solid #f0f0f0;
  font-size: 14px;
}

.order-item:last-child {
  border-bottom: none;
}

.order-summary .subtotal,
.order-summary .shipping {
  display: flex;
  justify-content: space-between;
  padding: 10px 0;
  font-size: 14px;
  color: #666;
}

.order-summary .total {
  display: flex;
  justify-content: space-between;
  padding: 20px 0;
  border-top: 2px solid #f0f0f0;
  font-size: 18px;
  font-weight: bold;
  margin-top: 10px;
}

.order-summary .total span:last-child {
  color: #ff4757;
  font-size: 24px;
}

.btn-submit {
  width: 100%;
  background: linear-gradient(135deg, #ff4757, #ff6b81);
  color: #fff;
  padding: 15px;
  border-radius: 30px;
  font-size: 16px;
  font-weight: bold;
  margin-top: 20px;
  transition: all 0.3s;
}

.btn-submit:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 20px rgba(255, 71, 87, 0.4);
}

/* ============ 成功页面 ============ */
.success-page {
  text-align: center;
  background: #fff;
  border-radius: 12px;
  padding: 80px 30px;
}

.success-icon {
  width: 100px;
  height: 100px;
  background: linear-gradient(135deg, #2ed573, #7bed9f);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 50px;
  color: #fff;
  margin: 0 auto 25px;
}

.success-page h2 {
  font-size: 28px;
  color: #1a2a6c;
  margin-bottom: 15px;
}

.success-page p {
  color: #666;
  font-size: 15px;
  margin-bottom: 10px;
}

.success-order-no {
  background: #f5f7fa;
  padding: 15px 30px;
  border-radius: 8px;
  display: inline-block;
  margin: 20px 0;
  font-family: monospace;
  font-size: 16px;
  color: #333;
}

.success-actions {
  margin-top: 30px;
  display: flex;
  gap: 15px;
  justify-content: center;
}

/* ============ 关于我们 ============ */
.about-banner {
  background: linear-gradient(135deg, #1a2a6c, #00a8ff);
  border-radius: 12px;
  padding: 60px 40px;
  color: #fff;
  text-align: center;
  margin-bottom: 30px;
}

.about-banner h1 {
  font-size: 36px;
  margin-bottom: 15px;
}

.about-banner p {
  font-size: 16px;
  opacity: 0.9;
}

.about-section {
  background: #fff;
  border-radius: 12px;
  padding: 40px;
  margin-bottom: 25px;
}

.about-section h2 {
  font-size: 22px;
  color: #1a2a6c;
  margin-bottom: 20px;
  padding-bottom: 12px;
  border-bottom: 2px solid #f5f7fa;
}

.about-section p {
  font-size: 15px;
  color: #555;
  line-height: 2;
  margin-bottom: 15px;
}

.stats {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
  margin-top: 30px;
}

.stat-item {
  text-align: center;
  padding: 25px;
  background: linear-gradient(135deg, #f5f7fa, #e8f4ff);
  border-radius: 10px;
}

.stat-number {
  font-size: 36px;
  font-weight: bold;
  color: #00a8ff;
  margin-bottom: 5px;
}

.stat-label {
  font-size: 13px;
  color: #666;
}

/* ============ Toast提示 ============ */
.toast {
  position: fixed;
  top: 80px;
  left: 50%;
  transform: translateX(-50%) translateY(-100px);
  background: #333;
  color: #fff;
  padding: 12px 25px;
  border-radius: 8px;
  font-size: 14px;
  z-index: 9999;
  transition: transform 0.3s ease;
  box-shadow: 0 5px 20px rgba(0,0,0,0.2);
}

.toast.show {
  transform: translateX(-50%) translateY(0);
}

/* ============ 响应式 ============ */
@media (max-width: 1024px) {
  .product-grid {
    grid-template-columns: repeat(3, 1fr);
  }
  .detail-top {
    grid-template-columns: 1fr;
  }
  .detail-img {
    height: 300px;
  }
  .checkout-page {
    grid-template-columns: 1fr;
  }
  .footer-grid {
    grid-template-columns: 1fr 1fr;
  }
}

@media (max-width: 768px) {
  .product-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  .features, .stats {
    grid-template-columns: repeat(2, 1fr);
  }
  .nav-menu {
    display: none;
  }
  .banner-content h2 {
    font-size: 28px;
  }
  .cart-table th:nth-child(3),
  .cart-table td:nth-child(3) {
    display: none;
  }
}

@media (max-width: 480px) {
  .product-grid {
    grid-template-columns: 1fr;
  }
  .features, .stats {
    grid-template-columns: 1fr;
  }
  .footer-grid {
    grid-template-columns: 1fr;
  }
  .banner {
    height: 300px;
  }
}