/* Reset & base styles */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  font-family: var(--font-body);
  color: var(--color-ink);
  background-color: var(--color-ground);
  font-size: 16px;
  line-height: 1.5;
  -webkit-text-size-adjust: 100%;
}

body {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  accent-color: var(--color-accent);
}

::selection {
  background-color: color-mix(in oklch, var(--color-accent) 25%, transparent);
  color: var(--color-ink);
}

:focus-visible {
  outline: 2px solid var(--color-accent);
  outline-offset: 2px;
}

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

button, input, select {
  font: inherit;
  color: inherit;
}

a {
  color: var(--color-ink);
  text-underline-offset: 3px;
}

/* Layout container */
.site-container {
  width: 100%;
  max-width: 1160px;
  margin-inline: auto;
  padding-inline: var(--space-4);
}

/* Demo Announcement Banner */
.demo-banner {
  background-color: var(--color-surface-soft);
  color: var(--color-ink);
  padding-block: var(--space-3);
  border-bottom: 2px solid color-mix(in oklch, var(--color-accent) 30%, transparent);
  font-size: var(--font-caption);
}

.demo-banner-content {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: var(--space-2);
}

.demo-tag {
  font-weight: 700;
  color: var(--color-accent);
  letter-spacing: normal;
}

/* Header */
.site-header {
  background-color: var(--color-surface);
  padding-block: var(--space-4);
  border-bottom: 1px solid var(--color-surface-soft);
}

.header-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: var(--space-4);
}

.brand-title {
  font-family: var(--font-display);
  font-size: 1.5rem;
  font-weight: 700;
  letter-spacing: -0.02em;
  color: var(--color-ink);
  text-decoration: none;
}

.brand-title span {
  color: var(--color-accent);
}

.cart-toggle-btn {
  background-color: var(--color-surface-soft);
  border: none;
  border-radius: var(--radius-sharp);
  padding: var(--space-2) var(--space-4);
  font-weight: 600;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
}

.cart-toggle-btn:hover {
  background-color: color-mix(in oklch, var(--color-accent) 15%, var(--color-surface-soft));
}

.cart-badge {
  background-color: var(--color-accent);
  color: var(--color-surface);
  font-size: 0.75rem;
  font-weight: 700;
  border-radius: 999px;
  padding: 0.1rem 0.45rem;
  font-variant-numeric: tabular-nums;
}

/* Hero Section */
.hero-section {
  padding-block: var(--space-8);
  background-color: var(--color-surface);
}

.hero-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-6);
  align-items: center;
}

@media (min-width: 768px) {
  .hero-grid {
    grid-template-columns: 1.2fr 1fr;
    gap: var(--space-10);
  }
}

.hero-content h1 {
  font-family: var(--font-display);
  font-size: var(--font-size-hero);
  line-height: 1.1;
  letter-spacing: -0.03em;
  color: var(--color-ink);
  text-wrap: balance;
  margin-bottom: var(--space-3);
}

.hero-lead {
  font-size: var(--font-size-lead);
  color: var(--color-ink-muted);
  text-wrap: pretty;
  margin-bottom: var(--space-6);
  max-width: 50ch;
}

.hero-notice-card {
  background-color: var(--color-ground);
  padding: var(--space-4);
  border-radius: var(--radius-sharp);
}

.hero-notice-card p {
  font-size: var(--font-caption);
  color: var(--color-ink-muted);
}

.hero-img-wrap {
  border-radius: var(--radius-sharp);
  overflow: hidden;
  background-color: var(--color-surface-soft);
}

.hero-img-wrap img {
  width: 100%;
  height: auto;
  object-fit: cover;
}

/* Main Shop Area */
.shop-section {
  padding-block: var(--space-8) var(--space-12);
}

.shop-layout {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-8);
}

@media (min-width: 960px) {
  .shop-layout {
    grid-template-columns: 2fr 1fr;
    align-items: start;
  }
}

/* Controls bar: Search & Filters */
.controls-card {
  background-color: var(--color-surface);
  padding: var(--space-5);
  border-radius: var(--radius-sharp);
  margin-bottom: var(--space-6);
}

.search-box-row {
  margin-bottom: var(--space-4);
}

.search-label {
  display: block;
  font-weight: 600;
  font-size: var(--font-caption);
  margin-bottom: var(--space-1);
}

.search-input {
  width: 100%;
  padding: var(--space-3);
  border: 1px solid var(--color-surface-soft);
  background-color: var(--color-ground);
  border-radius: var(--radius-sharp);
  color: var(--color-ink);
}

.search-input:focus {
  background-color: var(--color-surface);
  border-color: var(--color-accent);
}

.filter-group {
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
}

.filter-label {
  font-weight: 600;
  font-size: var(--font-caption);
}

.filter-pills {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
}

.filter-btn {
  background-color: var(--color-ground);
  border: none;
  padding: var(--space-2) var(--space-4);
  border-radius: var(--radius-sharp);
  font-size: var(--font-caption);
  font-weight: 600;
  cursor: pointer;
  color: var(--color-ink);
}

.filter-btn[aria-pressed="true"] {
  background-color: var(--color-accent);
  color: var(--color-surface);
}

.filter-btn:hover:not([aria-pressed="true"]) {
  background-color: var(--color-surface-soft);
}

/* Catalog results count */
.catalog-status {
  margin-bottom: var(--space-4);
  font-size: var(--font-caption);
  color: var(--color-ink-muted);
}

/* Books Grid */
.books-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-4);
}

@media (min-width: 580px) {
  .books-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

.book-card {
  background-color: var(--color-surface);
  padding: var(--space-5);
  border-radius: var(--radius-sharp);
  display: flex;
  flex-direction: column;
  justify-content: space-between;
}

.book-card-category {
  font-size: 0.8rem;
  color: var(--color-accent);
  font-weight: 600;
  margin-bottom: var(--space-1);
}

.book-card-title {
  font-family: var(--font-display);
  font-size: var(--font-size-title);
  line-height: 1.25;
  margin-bottom: var(--space-1);
  color: var(--color-ink);
}

.book-card-author {
  font-size: var(--font-caption);
  color: var(--color-ink-muted);
  margin-bottom: var(--space-3);
}

.book-card-desc {
  font-size: var(--font-caption);
  color: var(--color-ink);
  line-height: 1.45;
  margin-bottom: var(--space-4);
  flex-grow: 1;
}

.book-card-footer {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: var(--space-3);
  padding-top: var(--space-3);
  border-top: 1px solid var(--color-surface-soft);
}

.book-price {
  font-size: 1.2rem;
  font-weight: 700;
  font-variant-numeric: tabular-nums;
  color: var(--color-ink);
}

.add-btn {
  background-color: var(--color-accent);
  color: var(--color-surface);
  border: none;
  border-radius: var(--radius-sharp);
  padding: var(--space-2) var(--space-4);
  font-weight: 600;
  font-size: var(--font-caption);
  cursor: pointer;
  min-height: 44px;
}

.add-btn:hover {
  background-color: color-mix(in oklch, var(--color-accent) 85%, black);
}

/* Empty state */
.empty-results {
  background-color: var(--color-surface);
  padding: var(--space-8);
  text-align: center;
  border-radius: var(--radius-sharp);
}

.empty-results p {
  color: var(--color-ink-muted);
  margin-bottom: var(--space-4);
}

.reset-search-btn {
  background-color: var(--color-surface-soft);
  border: none;
  padding: var(--space-2) var(--space-4);
  font-weight: 600;
  cursor: pointer;
  border-radius: var(--radius-sharp);
}

/* Cart Panel / Aside */
.cart-panel {
  background-color: var(--color-surface);
  padding: var(--space-6);
  border-radius: var(--radius-sharp);
  position: sticky;
  top: var(--space-4);
}

.cart-panel-header {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  border-bottom: 2px solid var(--color-surface-soft);
  padding-bottom: var(--space-3);
  margin-bottom: var(--space-4);
}

.cart-panel-title {
  font-family: var(--font-display);
  font-size: var(--font-size-title);
}

.cart-items-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: var(--space-4);
  margin-bottom: var(--space-6);
}

.cart-item {
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
  padding-bottom: var(--space-3);
  border-bottom: 1px solid var(--color-surface-soft);
}

.cart-item-info {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  gap: var(--space-2);
}

.cart-item-title {
  font-weight: 600;
  font-size: var(--font-caption);
  line-height: 1.3;
}

.cart-item-price {
  font-size: var(--font-caption);
  font-weight: 700;
  font-variant-numeric: tabular-nums;
  white-space: nowrap;
}

.cart-item-actions {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.qty-control {
  display: inline-flex;
  align-items: center;
  background-color: var(--color-ground);
  border-radius: var(--radius-sharp);
  overflow: hidden;
}

.qty-btn {
  width: 36px;
  height: 36px;
  border: none;
  background-color: var(--color-ground);
  cursor: pointer;
  font-weight: 700;
  font-size: 1.1rem;
  display: flex;
  align-items: center;
  justify-content: center;
}

.qty-btn:hover {
  background-color: var(--color-surface-soft);
}

.qty-val {
  min-width: 32px;
  text-align: center;
  font-weight: 600;
  font-size: var(--font-caption);
  font-variant-numeric: tabular-nums;
}

.remove-btn {
  background: none;
  border: none;
  color: var(--color-ink-muted);
  font-size: var(--font-caption);
  cursor: pointer;
  text-decoration: underline;
  padding: var(--space-2);
}

.remove-btn:hover {
  color: var(--color-accent);
}

/* Cart Summary Calculations */
.cart-summary {
  background-color: var(--color-ground);
  padding: var(--space-4);
  border-radius: var(--radius-sharp);
  margin-bottom: var(--space-4);
}

.summary-row {
  display: flex;
  justify-content: space-between;
  font-size: var(--font-caption);
  margin-bottom: var(--space-2);
  font-variant-numeric: tabular-nums;
}

.summary-row.total-row {
  margin-top: var(--space-3);
  padding-top: var(--space-3);
  border-top: 1px solid var(--color-surface-soft);
  font-size: 1.1rem;
  font-weight: 700;
}

.shipping-hint {
  font-size: 0.8rem;
  color: var(--color-ink-muted);
  line-height: 1.35;
  margin-top: var(--space-2);
}

.shipping-free-active {
  color: #2E6838;
  font-weight: 600;
}

/* Demo Checkout Button */
.checkout-demo-btn {
  width: 100%;
  background-color: var(--color-accent);
  color: var(--color-surface);
  border: none;
  border-radius: var(--radius-sharp);
  padding: var(--space-3) var(--space-4);
  font-weight: 700;
  cursor: pointer;
  min-height: 48px;
  font-size: var(--font-body);
}

.checkout-demo-btn:hover {
  background-color: color-mix(in oklch, var(--color-accent) 85%, black);
}

.empty-cart-message {
  color: var(--color-ink-muted);
  font-size: var(--font-caption);
  padding-block: var(--space-6);
  text-align: center;
}

/* Checkout Demo Modal Notification */
.demo-dialog {
  margin: auto;
  padding: var(--space-6);
  border: none;
  border-radius: var(--radius-sharp);
  background-color: var(--color-surface);
  box-shadow: 0 12px 36px rgba(0,0,0,0.2);
  max-width: 480px;
  width: 90%;
}

.demo-dialog::backdrop {
  background: rgba(44, 38, 33, 0.45);
}

.demo-dialog h3 {
  font-family: var(--font-display);
  font-size: var(--font-size-title);
  margin-bottom: var(--space-2);
}

.demo-dialog p {
  font-size: var(--font-caption);
  color: var(--color-ink-muted);
  margin-bottom: var(--space-4);
}

.dialog-close-btn {
  background-color: var(--color-ink);
  color: var(--color-surface);
  border: none;
  padding: var(--space-2) var(--space-4);
  border-radius: var(--radius-sharp);
  font-weight: 600;
  cursor: pointer;
}

/* Footer */
.site-footer {
  margin-top: auto;
  background-color: var(--color-surface);
  border-top: 1px solid var(--color-surface-soft);
  padding-block: var(--space-8);
}

.footer-inner {
  display: flex;
  flex-direction: column;
  gap: var(--space-4);
  justify-content: space-between;
}

@media (min-width: 640px) {
  .footer-inner {
    flex-direction: row;
    align-items: center;
  }
}

.footer-brand {
  font-family: var(--font-display);
  font-size: 1.5rem;
  font-weight: 700;
}

.footer-brand span {
  color: var(--color-accent);
}

.footer-copy {
  font-size: var(--font-caption);
  color: var(--color-ink-muted);
}