:root {
  --background: 42 38% 97%;
  --foreground: 224 25% 15%;
  --card: 0 0% 100%;
  --card-foreground: 224 25% 15%;
  --popover: 0 0% 100%;
  --popover-foreground: 224 25% 15%;
  --primary: 25 92% 48%;
  --primary-foreground: 0 0% 100%;
  --secondary: 218 28% 18%;
  --secondary-foreground: 0 0% 100%;
  --muted: 35 22% 90%;
  --muted-foreground: 224 12% 42%;
  --accent: 331 62% 46%;
  --accent-foreground: 0 0% 100%;
  --destructive: 0 72% 45%;
  --destructive-foreground: 0 0% 100%;
  --success: 148 64% 32%;
  --success-foreground: 0 0% 100%;
  --warning: 40 90% 45%;
  --warning-foreground: 224 25% 15%;
  --info: 214 85% 45%;
  --info-foreground: 0 0% 100%;
  --border: 35 18% 82%;
  --input: 35 18% 82%;
  --ring: 25 92% 48%;
  --radius: 0.625rem;
  --shadow-sm: 0 1px 2px hsl(var(--foreground) / 0.05);
  --shadow-md: 0 4px 12px hsl(var(--foreground) / 0.08);
  --shadow-lg: 0 12px 32px hsl(var(--foreground) / 0.12);
  --shadow-elegant: 0 18px 48px hsl(var(--primary) / 0.22);
  --transition-fast: 150ms cubic-bezier(0.4, 0, 0.2, 1);
  --transition: 200ms cubic-bezier(0.4, 0, 0.2, 1);
  --transition-smooth: 300ms cubic-bezier(0.4, 0, 0.2, 1);
  --font-sans: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
}

.dark {
  --background: 224 26% 9%;
  --foreground: 42 32% 94%;
  --card: 224 24% 13%;
  --card-foreground: 42 32% 94%;
  --popover: 224 24% 13%;
  --popover-foreground: 42 32% 94%;
  --primary: 26 95% 56%;
  --primary-foreground: 224 26% 9%;
  --secondary: 35 25% 88%;
  --secondary-foreground: 224 26% 9%;
  --muted: 224 18% 20%;
  --muted-foreground: 42 16% 72%;
  --accent: 331 76% 62%;
  --accent-foreground: 224 26% 9%;
  --destructive: 0 68% 58%;
  --destructive-foreground: 224 26% 9%;
  --success: 148 58% 48%;
  --success-foreground: 224 26% 9%;
  --warning: 42 92% 58%;
  --warning-foreground: 224 26% 9%;
  --info: 214 82% 62%;
  --info-foreground: 224 26% 9%;
  --border: 224 18% 26%;
  --input: 224 18% 26%;
  --ring: 26 95% 56%;
}

* { box-sizing: border-box; }
html { min-height: 100%; scroll-behavior: smooth; }
body {
  margin: 0;
  min-height: 100vh;
  font-family: var(--font-sans);
  background: hsl(var(--background));
  color: hsl(var(--foreground));
  font-size: 16px;
  line-height: 1.5;
}
a { color: inherit; text-decoration: none; }
button, input, select, textarea { font: inherit; }
button { cursor: pointer; }
img { max-width: 100%; display: block; }

.site-nav {
  position: sticky;
  top: 0;
  z-index: 50;
  background: hsl(var(--popover) / 0.94);
  backdrop-filter: blur(16px);
  border-bottom: 1px solid hsl(var(--border));
  padding-top: env(safe-area-inset-top);
}
.nav-inner {
  max-width: 1280px;
  margin: 0 auto;
  min-height: 72px;
  padding: 0 16px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
}
.logo { display: flex; align-items: center; gap: 12px; font-weight: 700; letter-spacing: -0.03em; font-size: 20px; }
.logo-mark { width: 40px; height: 40px; border-radius: 14px; display: grid; place-items: center; background: hsl(var(--primary)); color: hsl(var(--primary-foreground)); box-shadow: var(--shadow-elegant); }
.nav-links { display: none; align-items: center; gap: 8px; }
.nav-link { min-height: 44px; display: inline-flex; align-items: center; border-radius: calc(var(--radius) - 2px); padding: 0 12px; color: hsl(var(--muted-foreground)); font-weight: 500; transition: background var(--transition-fast), color var(--transition-fast); }
.nav-link:hover, .nav-link.active { color: hsl(var(--foreground)); background: hsl(var(--muted)); }
.nav-actions { display: flex; align-items: center; gap: 8px; }
.cart-pill { min-height: 44px; display: inline-flex; align-items: center; gap: 8px; border-radius: 999px; padding: 0 12px; background: hsl(var(--secondary)); color: hsl(var(--secondary-foreground)); font-weight: 600; }
.theme-toggle { min-width: 44px; min-height: 44px; border: 1px solid hsl(var(--border)); border-radius: calc(var(--radius) - 2px); background: hsl(var(--card)); color: hsl(var(--card-foreground)); }
.page-shell { max-width: 1280px; margin: 0 auto; padding: 32px 16px 96px; }
.hero { display: grid; gap: 24px; align-items: center; margin-bottom: 32px; padding: 24px; border-radius: calc(var(--radius) + 4px); background: linear-gradient(135deg, hsl(var(--primary) / 0.16), hsl(var(--accent) / 0.12)), hsl(var(--card)); box-shadow: var(--shadow-sm); border: 1px solid hsl(var(--border)); }
.eyebrow { color: hsl(var(--muted-foreground)); font-size: 14px; font-weight: 500; }
h1, h2, h3 { margin: 0; line-height: 1.15; letter-spacing: -0.03em; }
h1 { font-size: clamp(32px, 7vw, 48px); font-weight: 700; }
h2 { font-size: clamp(24px, 4vw, 30px); font-weight: 600; }
h3 { font-size: 18px; font-weight: 600; }
p { margin: 0; }
.muted { color: hsl(var(--muted-foreground)); }
.hero-copy { display: grid; gap: 16px; max-width: 720px; }
.hero-actions, .button-row { display: flex; flex-wrap: wrap; gap: 12px; align-items: center; }
.btn { min-height: 44px; border: 1px solid hsl(var(--border)); border-radius: calc(var(--radius) - 2px); padding: 0 16px; display: inline-flex; align-items: center; justify-content: center; gap: 8px; font-weight: 600; background: hsl(var(--card)); color: hsl(var(--card-foreground)); transition: transform var(--transition-fast), box-shadow var(--transition-fast), background var(--transition-fast); }
.btn:hover { transform: translateY(-2px); box-shadow: var(--shadow-md); }
.btn:focus-visible, input:focus-visible, select:focus-visible, textarea:focus-visible { outline: 2px solid hsl(var(--ring)); outline-offset: 2px; }
.btn-primary { background: hsl(var(--primary)); color: hsl(var(--primary-foreground)); border-color: hsl(var(--primary)); }
.btn-secondary { background: hsl(var(--secondary)); color: hsl(var(--secondary-foreground)); border-color: hsl(var(--secondary)); }
.btn-danger { background: hsl(var(--destructive)); color: hsl(var(--destructive-foreground)); border-color: hsl(var(--destructive)); }
.btn-ghost { background: transparent; }
.btn[disabled] { opacity: 0.55; cursor: not-allowed; transform: none; box-shadow: none; }
.layout { display: grid; gap: 24px; }
.sidebar { background: hsl(var(--card)); border: 1px solid hsl(var(--border)); border-radius: var(--radius); padding: 16px; box-shadow: var(--shadow-sm); align-self: start; }
.sidebar h2 { font-size: 18px; margin-bottom: 12px; }
.category-list { display: grid; gap: 8px; }
.category-btn { width: 100%; min-height: 44px; border: 1px solid hsl(var(--border)); border-radius: calc(var(--radius) - 2px); background: hsl(var(--card)); color: hsl(var(--card-foreground)); text-align: left; padding: 0 12px; font-weight: 500; }
.category-btn.active { border-color: hsl(var(--primary)); background: hsl(var(--primary) / 0.12); color: hsl(var(--primary)); }
.toolbar { display: grid; gap: 12px; margin-bottom: 20px; }
.input, .select, .textarea { width: 100%; min-height: 44px; border: 1px solid hsl(var(--input)); border-radius: calc(var(--radius) - 2px); background: hsl(var(--card)); color: hsl(var(--card-foreground)); padding: 10px 12px; font-size: max(16px, 1rem); }
.textarea { min-height: 132px; resize: vertical; }
.grid { display: grid; grid-template-columns: 1fr; gap: 16px; }
.card { background: hsl(var(--card)); color: hsl(var(--card-foreground)); border: 1px solid hsl(var(--border)); border-radius: var(--radius); box-shadow: var(--shadow-sm); overflow: hidden; transition: transform var(--transition), box-shadow var(--transition); }
.card:hover { transform: translateY(-2px); box-shadow: var(--shadow-md); }
.art-link { display: block; background: hsl(var(--muted)); }
.art-image { width: 100%; aspect-ratio: 4 / 3; object-fit: cover; }
.card-body { padding: 16px; display: grid; gap: 12px; }
.card-title-row { display: flex; justify-content: space-between; gap: 12px; align-items: start; }
.price { font-size: 20px; font-weight: 700; color: hsl(var(--primary)); white-space: nowrap; }
.badge { display: inline-flex; align-items: center; min-height: 28px; border-radius: 999px; padding: 0 10px; font-size: 12px; font-weight: 600; background: hsl(var(--primary) / 0.12); color: hsl(var(--primary)); width: fit-content; }
.description { color: hsl(var(--muted-foreground)); font-size: 14px; min-height: 40px; }
.card-actions { display: grid; grid-template-columns: 1fr; gap: 8px; }
.product-layout { display: grid; gap: 24px; }
.product-image { width: 100%; aspect-ratio: 1 / 1; object-fit: cover; border-radius: var(--radius); background: hsl(var(--muted)); box-shadow: var(--shadow-md); }
.panel { background: hsl(var(--card)); border: 1px solid hsl(var(--border)); border-radius: var(--radius); box-shadow: var(--shadow-sm); padding: 20px; display: grid; gap: 16px; }
.seller { display: flex; align-items: center; gap: 12px; }
.avatar { width: 48px; height: 48px; border-radius: 999px; display: grid; place-items: center; background: hsl(var(--accent)); color: hsl(var(--accent-foreground)); font-weight: 700; }
.details-list { display: grid; gap: 10px; }
.detail-row { display: flex; justify-content: space-between; gap: 16px; border-bottom: 1px solid hsl(var(--border)); padding-bottom: 10px; }
.review { border-top: 1px solid hsl(var(--border)); padding-top: 14px; display: grid; gap: 6px; }
.cart-list { display: grid; gap: 12px; }
.cart-item { display: grid; grid-template-columns: 88px 1fr; gap: 12px; align-items: center; background: hsl(var(--card)); border: 1px solid hsl(var(--border)); border-radius: var(--radius); padding: 12px; }
.cart-item img { width: 88px; height: 88px; border-radius: calc(var(--radius) - 2px); object-fit: cover; background: hsl(var(--muted)); }
.qty-row { display: flex; align-items: center; gap: 8px; flex-wrap: wrap; }
.qty-btn { min-width: 44px; min-height: 44px; border-radius: calc(var(--radius) - 2px); border: 1px solid hsl(var(--border)); background: hsl(var(--card)); color: hsl(var(--card-foreground)); font-weight: 700; }
.summary { position: sticky; top: 96px; align-self: start; }
.form-grid { display: grid; gap: 16px; }
.form-field { display: grid; gap: 6px; }
.form-field label { font-weight: 600; }
.two-col { display: grid; gap: 16px; }
.suggestions { display: grid; gap: 8px; margin-top: 8px; }
.suggestion-btn { min-height: 44px; text-align: left; border: 1px solid hsl(var(--border)); border-radius: calc(var(--radius) - 2px); background: hsl(var(--popover)); color: hsl(var(--popover-foreground)); padding: 10px 12px; }
.empty-card, .center-page { min-height: 70vh; display: grid; place-items: center; text-align: center; }
.empty-card { min-height: auto; max-width: 560px; padding: 32px; background: hsl(var(--card)); border: 1px solid hsl(var(--border)); border-radius: var(--radius); box-shadow: var(--shadow-sm); gap: 16px; }
.toast { position: fixed; left: 16px; right: 16px; bottom: calc(16px + env(safe-area-inset-bottom)); z-index: 100; min-height: 44px; display: none; align-items: center; justify-content: center; padding: 12px 16px; border-radius: var(--radius); background: hsl(var(--foreground)); color: hsl(var(--background)); box-shadow: var(--shadow-lg); font-weight: 600; text-align: center; }
.toast.show { display: flex; animation: rise var(--transition-smooth); }
@keyframes rise { from { transform: translateY(12px); opacity: 0; } to { transform: translateY(0); opacity: 1; } }
@media (min-width: 640px) {
  .nav-inner, .page-shell { padding-left: 24px; padding-right: 24px; }
  .toolbar { grid-template-columns: 1fr 220px; }
  .grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .card-actions { grid-template-columns: 1fr 1fr; }
  .card-actions .wide { grid-column: span 2; }
  .two-col { grid-template-columns: 1fr 1fr; }
}
@media (min-width: 900px) {
  .nav-links { display: flex; }
  .hero { padding: 40px; }
  .layout { grid-template-columns: 240px 1fr; align-items: start; }
  .grid { grid-template-columns: repeat(3, minmax(0, 1fr)); }
  .product-layout { grid-template-columns: minmax(0, 1.1fr) minmax(360px, 0.9fr); }
  .checkout-layout, .cart-layout { display: grid; grid-template-columns: minmax(0, 1fr) 360px; gap: 24px; align-items: start; }
}
@media (min-width: 1180px) { .grid { grid-template-columns: repeat(4, minmax(0, 1fr)); } }