:root {
  --color-text: #1a1a1a;
  --color-muted: #666;
  --color-accent: #0066cc;
  --color-border: #e5e5e5;
  --color-bg: #fff;
  --color-bg-soft: #f7f7f7;
  --max-width: 1200px;
  --radius: 8px;
}

* { margin: 0; padding: 0; box-sizing: border-box; }

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  color: var(--color-text);
  background: var(--color-bg);
  line-height: 1.6;
}

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

.container { max-width: var(--max-width); margin: 0 auto; padding: 0 20px; }

.site-header {
  border-bottom: 1px solid var(--color-border);
  padding: 16px 0;
  position: sticky;
  top: 0;
  background: #fff;
  z-index: 10;
}
.site-header .container { display: flex; justify-content: space-between; align-items: center; }
.site-logo { font-weight: 700; font-size: 1.2rem; }
.site-header nav a { color: var(--color-muted); }

.site-footer {
  border-top: 1px solid var(--color-border);
  padding: 24px 0;
  margin-top: 60px;
  color: var(--color-muted);
  font-size: 0.9rem;
}

.hero { padding: 48px 0 24px; }
.hero h1 { font-size: 2rem; }
.hero p { color: var(--color-muted); }

.category-nav { display: flex; flex-wrap: wrap; gap: 10px; margin-bottom: 32px; }
.category-tag {
  padding: 6px 16px;
  border: 1px solid var(--color-border);
  border-radius: 999px;
  font-size: 0.9rem;
  transition: all .2s;
}
.category-tag:hover { border-color: var(--color-accent); color: var(--color-accent); }

.product-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
  padding-bottom: 40px;
}

.product-card {
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  overflow: hidden;
  transition: box-shadow .2s, transform .2s;
  display: block;
}
.product-card:hover { box-shadow: 0 8px 24px rgba(0,0,0,.08); transform: translateY(-2px); }

.product-image { aspect-ratio: 4/3; background: var(--color-bg-soft); overflow: hidden; }
.product-image img { width: 100%; height: 100%; object-fit: cover; }

.product-info { padding: 16px; }
.product-category { font-size: 0.8rem; color: var(--color-accent); }
.product-info h3 { font-size: 1.05rem; margin: 4px 0; }
.product-price { font-weight: 700; margin-top: 4px; }
.product-desc { color: var(--color-muted); font-size: 0.9rem; margin-top: 6px; }

.back-link { display: inline-block; margin: 24px 0; color: var(--color-muted); }
.page-title { margin-bottom: 24px; }

.product-detail { display: grid; grid-template-columns: 1fr 1fr; gap: 40px; padding-bottom: 60px; }
.product-images img { width: 100%; border-radius: var(--radius); margin-bottom: 12px; }
.product-detail-info h1 { font-size: 1.8rem; margin: 8px 0; }
.product-body { margin-top: 20px; }
.product-body ul { padding-left: 20px; margin: 12px 0; }

@media (max-width: 900px) {
  .product-grid { grid-template-columns: repeat(2, 1fr); }
  .product-detail { grid-template-columns: 1fr; }
}
@media (max-width: 600px) {
  .product-grid { grid-template-columns: 1fr; }
  .hero h1 { font-size: 1.5rem; }
}