/* ================================================================
   НомТан — style.css
   Architecture: Custom Properties → Reset → Layout → Components
   Naming: BEM (.block__element--modifier)
   ================================================================ */
 
/* ================================================================
   1. CUSTOM PROPERTIES
   ================================================================ */
:root {
  /* Colors — dark theme (default) */
  --clr-bg:        #0a0a0a;
  --clr-surface:   #141414;
  --clr-card:      #1c1c1c;
  --clr-border:    #262626;
  --clr-text:      #f0ece3;
  --clr-text-sub:  #8a8a8a;
  --clr-accent:    #c8a84b;
  --clr-accent-hv: #e2c46e;
  --clr-success:   #4caf82;
  --clr-danger:    #e05c5c;
  --clr-overlay:   rgba(0, 0, 0, 0.75);
 
  /* Typography */
  --ff-display: 'Times New Roman', Times, serif;
  --ff-body:    'DM Sans', system-ui, sans-serif;
 
  --fs-xs:  0.72rem;
  --fs-sm:  0.85rem;
  --fs-md:  1rem;
  --fs-lg:  1.15rem;
  --fs-xl:  1.4rem;
  --fs-2xl: 2rem;
  --fs-3xl: 3rem;
  --fs-4xl: clamp(2.4rem, 8vw, 5rem);
 
  --fw-light:  300;
  --fw-normal: 400;
  --fw-medium: 500;
  --fw-semi:   600;
  --fw-bold:   700;
 
  /* Spacing scale */
  --sp-1: 0.25rem;
  --sp-2: 0.5rem;
  --sp-3: 0.75rem;
  --sp-4: 1rem;
  --sp-5: 1.25rem;
  --sp-6: 1.5rem;
  --sp-8: 2rem;
  --sp-10: 2.5rem;
  --sp-12: 3rem;
  --sp-16: 4rem;
  --sp-20: 5rem;
 
  /* Layout */
  --container: 1200px;
  --px: clamp(1rem, 5vw, 2.5rem);
  --radius-sm:  6px;
  --radius-md:  12px;
  --radius-lg:  18px;
  --radius-xl:  24px;
  --radius-pill: 999px;
 
  /* Shadows */
  --shadow-sm:  0 1px 3px rgba(0,0,0,0.4);
  --shadow-md:  0 4px 16px rgba(0,0,0,0.5);
  --shadow-lg:  0 12px 40px rgba(0,0,0,0.6);
  --shadow-accent: 0 8px 32px rgba(200,168,75,0.15);
 
  /* Transitions */
  --ease-out:  cubic-bezier(0.16, 1, 0.3, 1);
  --ease-spring: cubic-bezier(0.34, 1.4, 0.64, 1);
  --dur-fast: 0.15s;
  --dur-base: 0.25s;
  --dur-slow: 0.4s;
 
  /* Z-index stack */
  --z-nav:     100;
  --z-drawer:  200;
  --z-modal:   300;
  --z-toast:   400;
}
 
/* Light theme override */
[data-theme="light"] {
  --clr-bg:       #f8f6f1;
  --clr-surface:  #ffffff;
  --clr-card:     #ffffff;
  --clr-border:   #e8e3d8;
  --clr-text:     #1a1a1a;
  --clr-text-sub: #6b6b6b;
  --clr-overlay:  rgba(0, 0, 0, 0.55);
  --shadow-sm:    0 1px 3px rgba(0,0,0,0.1);
  --shadow-md:    0 4px 16px rgba(0,0,0,0.08);
  --shadow-lg:    0 12px 40px rgba(0,0,0,0.12);
}
 
/* ================================================================
   2. RESET & BASE
   ================================================================ */
*,
*::before,
*::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}
 
html {
  font-size: 16px;
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}
 
body {
  font-family: var(--ff-body);
  font-size: var(--fs-md);
  font-weight: var(--fw-normal);
  color: var(--clr-text);
  background-color: var(--clr-bg);
  line-height: 1.6;
  overflow-x: hidden;
  transition: background-color var(--dur-base), color var(--dur-base);
  -webkit-tap-highlight-color: transparent;
}
 
img, svg { display: block; max-width: 100%; }
a { color: inherit; text-decoration: none; }
ul, ol { list-style: none; }
button, input, select, textarea { font-family: inherit; font-size: inherit; }
button { cursor: pointer; border: none; background: none; }
 
/* ================================================================
   3. ACCESSIBILITY
   ================================================================ */
.sr-only {
  position: absolute;
  width: 1px; height: 1px;
  padding: 0; margin: -1px;
  overflow: hidden;
  clip: rect(0,0,0,0);
  white-space: nowrap;
  border: 0;
}
 
.skip-link {
  position: absolute;
  top: -100%;
  left: var(--sp-4);
  background: var(--clr-accent);
  color: #000;
  padding: var(--sp-2) var(--sp-4);
  border-radius: var(--radius-sm);
  font-weight: var(--fw-semi);
  z-index: 999;
  transition: top var(--dur-fast);
}
.skip-link:focus { top: var(--sp-2); }
 
:focus-visible {
  outline: 2px solid var(--clr-accent);
  outline-offset: 3px;
  border-radius: var(--radius-sm);
}
 
/* ================================================================
   4. LAYOUT UTILITIES
   ================================================================ */
.container {
  width: 100%;
  max-width: var(--container);
  margin-inline: auto;
  padding-inline: var(--px);
}
 
.section {
  padding-block: clamp(var(--sp-12), 8vw, var(--sp-20));
}
 
.section__header {
  text-align: center;
  margin-bottom: clamp(var(--sp-8), 5vw, var(--sp-12));
}
 
.section__title {
  font-family: var(--ff-display);
  font-size: clamp(var(--fs-2xl), 5vw, var(--fs-3xl));
  font-weight: var(--fw-bold);
  line-height: 1.15;
  letter-spacing: -0.02em;
}
 
.section__title em {
  color: var(--clr-accent);
  font-style: italic;
}
 
.section__sub {
  margin-top: var(--sp-3);
  color: var(--clr-text-sub);
  font-size: var(--fs-lg);
}
 
/* ================================================================
   5. BUTTONS
   ================================================================ */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--sp-2);
  padding: 0.55em 1.3em;
  border-radius: var(--radius-pill);
  font-family: var(--ff-body);
  font-size: var(--fs-sm);
  font-weight: var(--fw-semi);
  letter-spacing: 0.01em;
  line-height: 1;
  white-space: nowrap;
  transition: background var(--dur-fast), color var(--dur-fast),
              border-color var(--dur-fast), transform var(--dur-fast),
              box-shadow var(--dur-fast);
  min-height: 40px;
  user-select: none;
}
 
.btn:active:not(:disabled) { transform: scale(0.97); }
.btn:disabled { opacity: 0.5; cursor: not-allowed; }
 
.btn--primary {
  background: var(--clr-accent);
  color: #000;
}
.btn--primary:hover:not(:disabled) {
  background: var(--clr-accent-hv);
  box-shadow: var(--shadow-accent);
}
 
.btn--outline {
  background: transparent;
  border: 1.5px solid var(--clr-border);
  color: var(--clr-text);
}
.btn--outline:hover:not(:disabled) {
  border-color: var(--clr-accent);
  color: var(--clr-accent);
}
 
.btn--ghost {
  background: transparent;
  color: var(--clr-text-sub);
}
.btn--ghost:hover:not(:disabled) { color: var(--clr-text); }
 
.btn--icon { padding: 0.5em; border-radius: var(--radius-md); min-height: 38px; min-width: 38px; }
.btn--lg   { font-size: var(--fs-md); min-height: 48px; padding: 0.7em 1.6em; }
.btn--full { width: 100%; }
 
/* ================================================================
   6. SITE HEADER & NAV
   ================================================================ */
.site-header {
  position: sticky;
  top: 0;
  z-index: var(--z-nav);
  background: color-mix(in srgb, var(--clr-bg) 85%, transparent);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--clr-border);
}
 
.nav {
  display: flex;
  align-items: center;
  height: 60px;
  gap: var(--sp-4);
}
 
.nav__logo {
  font-family: var(--ff-display);
  font-size: var(--fs-xl);
  font-weight: var(--fw-bold);
  color: var(--clr-accent);
  letter-spacing: -0.03em;
  flex-shrink: 0;
}
 
.nav__links {
  display: flex;
  gap: var(--sp-6);
  margin-left: var(--sp-8);
}
 
.nav__link {
  font-size: var(--fs-sm);
  font-weight: var(--fw-medium);
  color: var(--clr-text-sub);
  transition: color var(--dur-fast);
  position: relative;
  padding-bottom: 2px;
}
 
.nav__link::after {
  content: '';
  position: absolute;
  bottom: -2px; left: 0;
  width: 0; height: 1.5px;
  background: var(--clr-accent);
  transition: width var(--dur-base) var(--ease-out);
}
 
.nav__link:hover,
.nav__link.is-active {
  color: var(--clr-text);
}
.nav__link:hover::after,
.nav__link.is-active::after { width: 100%; }
 
.nav__actions {
  display: flex;
  align-items: center;
  gap: var(--sp-2);
  margin-left: auto;
}
 
.cart-badge {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 20px;
  height: 20px;
  padding: 0 4px;
  background: #000;
  color: var(--clr-accent);
  border-radius: var(--radius-pill);
  font-size: 0.68rem;
  font-weight: var(--fw-bold);
}
 
/* Hamburger */
.nav__hamburger {
  display: none;
  flex-direction: column;
  gap: 5px;
  padding: 8px 6px;
  border-radius: var(--radius-sm);
  min-width: 36px; min-height: 36px;
  justify-content: center;
}
.nav__hamburger span {
  display: block;
  width: 22px; height: 2px;
  background: var(--clr-text);
  border-radius: 2px;
  transition: transform var(--dur-base) var(--ease-out), opacity var(--dur-base);
}
.nav__hamburger[aria-expanded="true"] span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.nav__hamburger[aria-expanded="true"] span:nth-child(2) { opacity: 0; }
.nav__hamburger[aria-expanded="true"] span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }
 
/* Mobile nav */
.mobile-nav {
  background: var(--clr-surface);
  border-bottom: 1px solid var(--clr-border);
  padding: var(--sp-4) var(--px) var(--sp-5);
  animation: slideDown var(--dur-base) var(--ease-out);
}
.mobile-nav ul { display: flex; flex-direction: column; gap: 0; }
.mobile-nav__link {
  display: block;
  padding: var(--sp-4) 0;
  font-size: var(--fs-lg);
  font-weight: var(--fw-medium);
  border-bottom: 1px solid var(--clr-border);
  color: var(--clr-text-sub);
  transition: color var(--dur-fast), padding-left var(--dur-base);
}
.mobile-nav__link:last-child { border-bottom: none; }
.mobile-nav__link:hover { color: var(--clr-accent); padding-left: var(--sp-2); }
 
@keyframes slideDown {
  from { opacity: 0; transform: translateY(-10px); }
  to   { opacity: 1; transform: translateY(0); }
}
 
/* ================================================================
   7. HERO
   ================================================================ */
.hero {
  position: relative;
  min-height: clamp(560px, 85vh, 780px);
  display: flex;
  align-items: center;
  overflow: hidden;
  border-bottom: 1px solid var(--clr-border);
}
 
.hero__bg {
  position: absolute;
  inset: 0;
  pointer-events: none;
  overflow: hidden;
}
 
.hero__orb {
  position: absolute;
  border-radius: 50%;
  filter: blur(80px);
  opacity: 0.12;
  animation: float 12s ease-in-out infinite;
}
.hero__orb--1 {
  width: 600px; height: 600px;
  background: var(--clr-accent);
  top: -200px; left: -100px;
}
.hero__orb--2 {
  width: 400px; height: 400px;
  background: #6b8cba;
  bottom: -100px; right: -80px;
  animation-delay: -6s;
}
 
@keyframes float {
  0%, 100% { transform: translate(0, 0); }
  50%       { transform: translate(20px, -30px); }
}
 
.hero__inner {
  position: relative;
  z-index: 1;
  padding-block: var(--sp-20);
}
 
.hero__badge {
  display: inline-flex;
  align-items: center;
  gap: var(--sp-2);
  padding: var(--sp-1) var(--sp-4);
  background: color-mix(in srgb, var(--clr-accent) 12%, transparent);
  border: 1px solid color-mix(in srgb, var(--clr-accent) 35%, transparent);
  color: var(--clr-accent);
  border-radius: var(--radius-pill);
  font-size: var(--fs-xs);
  font-weight: var(--fw-semi);
  letter-spacing: 1.5px;
  text-transform: uppercase;
  margin-bottom: var(--sp-5);
}
 
.hero__heading {
  font-family: var(--ff-display);
  font-size: var(--fs-4xl);
  font-weight: var(--fw-bold);
  line-height: 1.0;
  letter-spacing: -0.03em;
  margin-bottom: var(--sp-5);
}
.hero__heading em {
  color: var(--clr-accent);
  font-style: italic;
}
 
.hero__sub {
  font-size: clamp(var(--fs-md), 2vw, var(--fs-lg));
  color: var(--clr-text-sub);
  max-width: 480px;
  line-height: 1.7;
  margin-bottom: var(--sp-8);
}
 
.hero__cta-group {
  display: flex;
  gap: var(--sp-3);
  flex-wrap: wrap;
}
 
.hero__stats {
  display: flex;
  gap: var(--sp-8);
  margin-top: var(--sp-12);
  padding-top: var(--sp-8);
  border-top: 1px solid var(--clr-border);
}
 
.stat-item__num {
  display: block;
  font-family: var(--ff-display);
  font-size: clamp(var(--fs-2xl), 4vw, var(--fs-3xl));
  font-weight: var(--fw-bold);
  color: var(--clr-accent);
  line-height: 1;
}
.stat-item__label {
  font-size: var(--fs-xs);
  color: var(--clr-text-sub);
  letter-spacing: 0.5px;
  margin-top: var(--sp-1);
}
 
/* ================================================================
   8. CATALOG TOOLBAR
   ================================================================ */
.catalog__toolbar {
  display: flex;
  align-items: flex-start;
  gap: var(--sp-4);
  flex-wrap: wrap;
  margin-bottom: var(--sp-4);
}
 
/* Search */
.search-field {
  position: relative;
  flex: 1;
  min-width: 220px;
  max-width: 360px;
}
.search-field__icon {
  position: absolute;
  left: var(--sp-3);
  top: 50%; transform: translateY(-50%);
  font-size: var(--fs-sm);
  pointer-events: none;
}
.search-field__input {
  width: 100%;
  padding: 0.65em 2.5em 0.65em 2.5em;
  background: var(--clr-card);
  border: 1.5px solid var(--clr-border);
  border-radius: var(--radius-pill);
  color: var(--clr-text);
  font-size: var(--fs-sm);
  outline: none;
  transition: border-color var(--dur-fast), box-shadow var(--dur-fast);
  min-height: 42px;
}
.search-field__input::placeholder { color: var(--clr-text-sub); }
.search-field__input:focus {
  border-color: var(--clr-accent);
  box-shadow: 0 0 0 3px color-mix(in srgb, var(--clr-accent) 15%, transparent);
}
.search-field__clear {
  position: absolute;
  right: var(--sp-3);
  top: 50%; transform: translateY(-50%);
  color: var(--clr-text-sub);
  font-size: var(--fs-sm);
  padding: 4px;
  border-radius: 50%;
  transition: color var(--dur-fast);
}
.search-field__clear:hover { color: var(--clr-danger); }
 
/* Filter tabs */
.filter-tabs {
  display: flex;
  gap: var(--sp-2);
  flex-wrap: wrap;
  align-items: center;
}
.filter-tab {
  padding: 0.4em 1em;
  border-radius: var(--radius-pill);
  border: 1.5px solid var(--clr-border);
  background: transparent;
  color: var(--clr-text-sub);
  font-size: var(--fs-xs);
  font-weight: var(--fw-medium);
  letter-spacing: 0.3px;
  transition: all var(--dur-fast);
  white-space: nowrap;
  min-height: 34px;
}
.filter-tab:hover {
  border-color: var(--clr-accent);
  color: var(--clr-accent);
}
.filter-tab.is-active {
  background: var(--clr-accent);
  border-color: var(--clr-accent);
  color: #000;
  font-weight: var(--fw-semi);
}
 
/* Sort */
.sort-select {
  padding: 0.55em 1em;
  background: var(--clr-card);
  border: 1.5px solid var(--clr-border);
  border-radius: var(--radius-pill);
  color: var(--clr-text);
  font-size: var(--fs-sm);
  font-weight: var(--fw-medium);
  outline: none;
  cursor: pointer;
  transition: border-color var(--dur-fast);
  min-height: 42px;
  appearance: none;
  -webkit-appearance: none;
  padding-right: 2em;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='8' viewBox='0 0 12 8'%3E%3Cpath d='M1 1l5 5 5-5' stroke='%238a8a8a' stroke-width='1.5' fill='none' stroke-linecap='round'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 0.8em center;
}
.sort-select:focus { border-color: var(--clr-accent); }
 
/* Result count */
.catalog__count {
  font-size: var(--fs-sm);
  color: var(--clr-text-sub);
  margin-bottom: var(--sp-5);
  min-height: 1.4em;
}
 
/* ================================================================
   9. BOOK GRID & CARD
   ================================================================ */
.book-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(min(200px, 44vw), 1fr));
  gap: clamp(var(--sp-4), 2vw, var(--sp-6));
}
 
.book-card {
  position: relative;
  display: flex;
  flex-direction: column;
  background: var(--clr-card);
  border: 1px solid var(--clr-border);
  border-radius: var(--radius-lg);
  overflow: hidden;
  cursor: pointer;
  transition: transform var(--dur-base) var(--ease-out),
              border-color var(--dur-base),
              box-shadow var(--dur-base);
}
.book-card:hover {
  transform: translateY(-5px);
  border-color: color-mix(in srgb, var(--clr-accent) 50%, transparent);
  box-shadow: var(--shadow-accent);
}
.book-card:focus-visible {
  outline: 2px solid var(--clr-accent);
  outline-offset: 2px;
}
.book-card:active { transform: scale(0.98); }
 
.book-card__cover {
  aspect-ratio: 3/4;
  display: flex;
  align-items: center;
  justify-content: center;
  background: linear-gradient(145deg, #222, #181818);
  font-size: clamp(2.5rem, 7vw, 3.8rem);
  position: relative;
  overflow: hidden;
}
 
.book-card__badge-new {
  position: absolute;
  top: var(--sp-2); right: var(--sp-2);
  background: var(--clr-accent);
  color: #000;
  font-size: 0.6rem;
  font-weight: var(--fw-bold);
  letter-spacing: 0.5px;
  padding: 2px 8px;
  border-radius: var(--radius-pill);
}
 
.book-card__genre-tag {
  position: absolute;
  bottom: var(--sp-2); left: var(--sp-2);
  background: rgba(0,0,0,0.7);
  color: var(--clr-accent);
  font-size: 0.58rem;
  font-weight: var(--fw-semi);
  letter-spacing: 0.8px;
  text-transform: uppercase;
  padding: 3px 8px;
  border-radius: var(--radius-pill);
  border: 1px solid color-mix(in srgb, var(--clr-accent) 30%, transparent);
}
 
.book-card__body {
  padding: var(--sp-4);
  display: flex;
  flex-direction: column;
  flex: 1;
  gap: var(--sp-1);
}
 
.book-card__title {
  font-family: var(--ff-display);
  font-size: clamp(0.85rem, 2.5vw, 1rem);
  font-weight: var(--fw-semi);
  line-height: 1.3;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}
 
.book-card__author {
  font-size: var(--fs-xs);
  color: var(--clr-text-sub);
}
 
.book-card__rating {
  display: flex;
  align-items: center;
  gap: var(--sp-2);
  margin-top: var(--sp-1);
}
.book-card__stars {
  color: var(--clr-accent);
  font-size: 0.68rem;
  letter-spacing: 1px;
}
.book-card__rating-num {
  font-size: var(--fs-xs);
  color: var(--clr-text-sub);
}
 
.book-card__footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--sp-2);
  margin-top: auto;
  padding-top: var(--sp-3);
}
 
.book-card__price {
  font-family: var(--ff-display);
  font-size: clamp(1rem, 3vw, 1.15rem);
  font-weight: var(--fw-bold);
  color: var(--clr-accent);
  white-space: nowrap;
}
.book-card__price sup {
  font-size: 0.6em;
  font-weight: var(--fw-normal);
  vertical-align: top;
  margin-top: 0.2em;
}
 
.book-card__add {
  padding: 0.3em 0.8em;
  border: 1.5px solid var(--clr-accent);
  color: var(--clr-accent);
  background: transparent;
  border-radius: var(--radius-md);
  font-size: var(--fs-xs);
  font-weight: var(--fw-semi);
  transition: background var(--dur-fast), color var(--dur-fast);
  white-space: nowrap;
  min-height: 30px;
}
.book-card__add:hover {
  background: var(--clr-accent);
  color: #000;
}
.book-card__add.is-added {
  background: var(--clr-success);
  border-color: var(--clr-success);
  color: #fff;
}
 
/* ================================================================
   10. EMPTY STATE
   ================================================================ */
.empty-state {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: var(--sp-4);
  padding: var(--sp-16) var(--sp-4);
  text-align: center;
  color: var(--clr-text-sub);
}
.empty-state__icon { font-size: 3rem; }
.empty-state__msg  { font-size: var(--fs-lg); }
 
/* ================================================================
   11. ABOUT / FEATURES
   ================================================================ */
.about {
  background: var(--clr-surface);
  border-top: 1px solid var(--clr-border);
}
 
.about__grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(min(240px, 100%), 1fr));
  gap: clamp(var(--sp-4), 2vw, var(--sp-6));
}
 
.feature-card {
  background: var(--clr-card);
  border: 1px solid var(--clr-border);
  border-radius: var(--radius-lg);
  padding: clamp(var(--sp-5), 3vw, var(--sp-8));
  transition: border-color var(--dur-base), transform var(--dur-base) var(--ease-out);
}
.feature-card:hover {
  border-color: color-mix(in srgb, var(--clr-accent) 40%, transparent);
  transform: translateY(-3px);
}
.feature-card__icon { font-size: 2rem; margin-bottom: var(--sp-4); }
.feature-card__title {
  font-family: var(--ff-display);
  font-size: var(--fs-xl);
  font-weight: var(--fw-semi);
  margin-bottom: var(--sp-2);
}
.feature-card__text {
  font-size: var(--fs-sm);
  color: var(--clr-text-sub);
  line-height: 1.7;
}
 
/* ================================================================
   12. FOOTER
   ================================================================ */
.site-footer {
  background: var(--clr-surface);
  border-top: 1px solid var(--clr-border);
  padding-block: var(--sp-8);
}
 
.site-footer__inner {
  display: flex;
  align-items: center;
  gap: var(--sp-6);
  flex-wrap: wrap;
  justify-content: space-between;
}
 
.site-footer__logo {
  font-family: var(--ff-display);
  font-size: var(--fs-xl);
  font-weight: var(--fw-bold);
  color: var(--clr-accent);
}
 
.site-footer__nav {
  display: flex;
  gap: var(--sp-5);
}
.site-footer__nav a {
  font-size: var(--fs-sm);
  color: var(--clr-text-sub);
  transition: color var(--dur-fast);
}
.site-footer__nav a:hover { color: var(--clr-accent); }
 
.site-footer__copy {
  font-size: var(--fs-xs);
  color: var(--clr-text-sub);
}
 
/* ================================================================
   13. MODAL OVERLAY
   ================================================================ */
.modal-overlay {
  position: fixed;
  inset: 0;
  z-index: var(--z-modal);
  background: var(--clr-overlay);
  backdrop-filter: blur(6px);
  -webkit-backdrop-filter: blur(6px);
  display: flex;
  align-items: flex-end;        /* Mobile: bottom sheet */
  justify-content: center;
  padding: 0;
  overflow-y: auto;
  animation: fadeIn var(--dur-base) var(--ease-out);
}
.modal-overlay[hidden] { display: none; }
 
@media (min-width: 600px) {
  .modal-overlay { align-items: center; padding: var(--sp-4); }
}
 
@keyframes fadeIn  { from { opacity: 0; } to { opacity: 1; } }
@keyframes slideUp { from { opacity: 0; transform: translateY(40px); } to { opacity: 1; transform: translateY(0); } }
@keyframes scaleIn { from { opacity: 0; transform: scale(0.94); } to { opacity: 1; transform: scale(1); } }
 
/* Base modal */
.modal {
  position: relative;
  background: var(--clr-surface);
  border: 1px solid var(--clr-border);
  width: 100%;
  border-radius: var(--radius-xl) var(--radius-xl) 0 0;
  max-height: 92vh;
  overflow-y: auto;
  padding: clamp(var(--sp-5), 4vw, var(--sp-8));
  padding-bottom: max(var(--sp-6), env(safe-area-inset-bottom));
  animation: slideUp var(--dur-slow) var(--ease-spring);
}
 
@media (min-width: 600px) {
  .modal {
    max-width: 600px;
    border-radius: var(--radius-xl);
    max-height: 90vh;
    animation: scaleIn var(--dur-base) var(--ease-out);
  }
  .modal--form { max-width: 540px; }
  .modal--center { max-width: 420px; text-align: center; }
}
 
.modal__close {
  position: absolute;
  top: clamp(var(--sp-4), 2vw, var(--sp-5));
  right: clamp(var(--sp-4), 2vw, var(--sp-5));
  width: 34px; height: 34px;
  border-radius: 50%;
  background: var(--clr-card);
  border: 1px solid var(--clr-border);
  color: var(--clr-text-sub);
  font-size: 0.9rem;
  display: flex; align-items: center; justify-content: center;
  transition: border-color var(--dur-fast), color var(--dur-fast);
  z-index: 1;
}
.modal__close:hover { border-color: var(--clr-danger); color: var(--clr-danger); }
 
/* Book detail modal */
.modal__book {
  display: flex;
  gap: clamp(var(--sp-4), 4vw, var(--sp-6));
  align-items: flex-start;
}
 
.modal__cover {
  flex-shrink: 0;
  width: clamp(90px, 22vw, 130px);
  aspect-ratio: 3/4;
  background: linear-gradient(145deg, #222, #181818);
  border-radius: var(--radius-md);
  display: flex; align-items: center; justify-content: center;
  font-size: clamp(2.2rem, 7vw, 3rem);
}
 
.modal__info { flex: 1; min-width: 0; }
.modal__genre {
  display: inline-block;
  background: color-mix(in srgb, var(--clr-accent) 12%, transparent);
  border: 1px solid color-mix(in srgb, var(--clr-accent) 30%, transparent);
  color: var(--clr-accent);
  font-size: var(--fs-xs);
  font-weight: var(--fw-semi);
  letter-spacing: 1px;
  text-transform: uppercase;
  padding: 2px 10px;
  border-radius: var(--radius-pill);
  margin-bottom: var(--sp-3);
}
.modal__title {
  font-family: var(--ff-display);
  font-size: clamp(var(--fs-lg), 3.5vw, var(--fs-2xl));
  font-weight: var(--fw-bold);
  line-height: 1.2;
  margin-bottom: var(--sp-2);
}
.modal__author { font-size: var(--fs-sm); color: var(--clr-text-sub); margin-bottom: var(--sp-4); }
.modal__desc   { font-size: var(--fs-sm); color: var(--clr-text-sub); line-height: 1.7; margin-bottom: var(--sp-4); }
.modal__rating { margin-bottom: var(--sp-4); font-size: var(--fs-sm); color: var(--clr-accent); }
.modal__price  {
  display: block;
  font-family: var(--ff-display);
  font-size: clamp(var(--fs-2xl), 5vw, 2.2rem);
  font-weight: var(--fw-bold);
  color: var(--clr-accent);
  margin-bottom: var(--sp-5);
}
.modal__actions { display: flex; gap: var(--sp-3); flex-wrap: wrap; }
 
@media (max-width: 420px) {
  .modal__book { flex-direction: column; align-items: center; text-align: center; }
  .modal__actions { justify-content: center; }
}
 
/* ================================================================
   14. CART DRAWER
   ================================================================ */
.drawer {
  background: var(--clr-surface);
  border: 1px solid var(--clr-border);
  width: 100%;
  max-width: 480px;
  border-radius: var(--radius-xl) var(--radius-xl) 0 0;
  max-height: 92vh;
  display: flex;
  flex-direction: column;
  animation: slideUp var(--dur-slow) var(--ease-spring);
}
@media (min-width: 600px) {
  .drawer { border-radius: var(--radius-xl); animation: scaleIn var(--dur-base) var(--ease-out); }
}
 
.drawer__head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: clamp(var(--sp-5), 3vw, var(--sp-6)) clamp(var(--sp-5), 4vw, var(--sp-6)) var(--sp-4);
  border-bottom: 1px solid var(--clr-border);
  flex-shrink: 0;
}
.drawer__title {
  font-family: var(--ff-display);
  font-size: var(--fs-xl);
  font-weight: var(--fw-semi);
}
.drawer__body {
  flex: 1;
  overflow-y: auto;
  padding: var(--sp-2) clamp(var(--sp-5), 4vw, var(--sp-6));
}
.drawer__foot {
  padding: var(--sp-4) clamp(var(--sp-5), 4vw, var(--sp-6));
  padding-bottom: max(var(--sp-5), env(safe-area-inset-bottom));
  border-top: 1px solid var(--clr-border);
  flex-shrink: 0;
  background: var(--clr-surface);
}
 
/* Cart items */
.cart-item {
  display: flex;
  align-items: center;
  gap: var(--sp-3);
  padding: var(--sp-4) 0;
  border-bottom: 1px solid var(--clr-border);
}
.cart-item:last-child { border-bottom: none; }
.cart-item__emoji { font-size: 1.8rem; flex-shrink: 0; }
.cart-item__info  { flex: 1; min-width: 0; }
.cart-item__name  {
  font-weight: var(--fw-medium);
  font-size: var(--fs-sm);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}
.cart-item__price { font-size: var(--fs-xs); color: var(--clr-accent); margin-top: 2px; }
.cart-item__remove {
  flex-shrink: 0;
  width: 32px; height: 32px;
  border-radius: 50%;
  color: var(--clr-text-sub);
  font-size: 0.85rem;
  display: flex; align-items: center; justify-content: center;
  transition: background var(--dur-fast), color var(--dur-fast);
}
.cart-item__remove:hover { background: color-mix(in srgb, var(--clr-danger) 15%, transparent); color: var(--clr-danger); }
 
/* Cart empty */
.cart-empty {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: var(--sp-3);
  padding: var(--sp-12) var(--sp-4);
  text-align: center;
  color: var(--clr-text-sub);
}
.cart-empty__icon { font-size: 3rem; }
 
/* Cart total */
.cart-total {
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-family: var(--ff-display);
  font-size: var(--fs-lg);
  margin-bottom: var(--sp-4);
}
.cart-total strong { color: var(--clr-accent); font-size: var(--fs-xl); }
 
/* ================================================================
   15. CHECKOUT FORM
   ================================================================ */
.checkout-form { display: flex; flex-direction: column; gap: var(--sp-4); }
.form-row { display: grid; grid-template-columns: 1fr 1fr; gap: var(--sp-4); }
 
@media (max-width: 400px) { .form-row { grid-template-columns: 1fr; } }
 
.form-field { display: flex; flex-direction: column; gap: var(--sp-1); }
.form-field__label {
  font-size: var(--fs-xs);
  font-weight: var(--fw-medium);
  color: var(--clr-text-sub);
  letter-spacing: 0.3px;
}
.form-field__label abbr {
  color: var(--clr-danger);
  text-decoration: none;
  margin-left: 2px;
}
.form-field__input {
  padding: 0.65em 1em;
  background: var(--clr-card);
  border: 1.5px solid var(--clr-border);
  border-radius: var(--radius-md);
  color: var(--clr-text);
  font-size: var(--fs-sm);
  outline: none;
  transition: border-color var(--dur-fast), box-shadow var(--dur-fast);
  min-height: 44px;
}
.form-field__input::placeholder { color: var(--clr-text-sub); }
.form-field__input:focus {
  border-color: var(--clr-accent);
  box-shadow: 0 0 0 3px color-mix(in srgb, var(--clr-accent) 12%, transparent);
}
.form-field__input.is-invalid {
  border-color: var(--clr-danger);
  box-shadow: 0 0 0 3px color-mix(in srgb, var(--clr-danger) 10%, transparent);
}
.form-field__error {
  font-size: var(--fs-xs);
  color: var(--clr-danger);
  min-height: 1.2em;
}
 
/* Order summary in checkout */
.order-summary {
  background: var(--clr-card);
  border: 1px solid var(--clr-border);
  border-radius: var(--radius-md);
  padding: var(--sp-4);
  font-size: var(--fs-sm);
}
.order-summary__row {
  display: flex;
  justify-content: space-between;
  padding: var(--sp-1) 0;
  color: var(--clr-text-sub);
}
.order-summary__total {
  display: flex;
  justify-content: space-between;
  padding-top: var(--sp-3);
  margin-top: var(--sp-2);
  border-top: 1px solid var(--clr-border);
  font-family: var(--ff-display);
  font-size: var(--fs-lg);
  font-weight: var(--fw-semi);
}
.order-summary__total strong { color: var(--clr-accent); }
 
.form-notice {
  font-size: var(--fs-xs);
  color: var(--clr-text-sub);
  background: var(--clr-card);
  border: 1px solid var(--clr-border);
  border-radius: var(--radius-md);
  padding: var(--sp-3) var(--sp-4);
  line-height: 1.6;
}
 
/* ================================================================
   16. SUCCESS STATE
   ================================================================ */
.success-state {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--sp-4);
  padding: var(--sp-6) var(--sp-2);
  text-align: center;
}
.success-state__icon {
  font-size: clamp(3rem, 10vw, 4.5rem);
  animation: bounce 0.6s var(--ease-spring);
}
@keyframes bounce {
  0%   { transform: scale(0); }
  70%  { transform: scale(1.15); }
  100% { transform: scale(1); }
}
.success-state__title {
  font-family: var(--ff-display);
  font-size: clamp(var(--fs-2xl), 5vw, var(--fs-3xl));
  font-weight: var(--fw-bold);
}
.success-state__msg {
  color: var(--clr-text-sub);
  font-size: var(--fs-md);
  line-height: 1.7;
}
 
/* ================================================================
   17. TOAST
   ================================================================ */
.toast-container {
  position: fixed;
  bottom: max(var(--sp-5), env(safe-area-inset-bottom, var(--sp-5)));
  right: var(--sp-4);
  z-index: var(--z-toast);
  display: flex;
  flex-direction: column;
  gap: var(--sp-2);
  pointer-events: none;
}
 
@media (max-width: 480px) {
  .toast-container { right: var(--sp-4); left: var(--sp-4); }
}
 
.toast {
  display: flex;
  align-items: center;
  gap: var(--sp-3);
  padding: var(--sp-3) var(--sp-4);
  background: var(--clr-surface);
  border: 1px solid var(--clr-border);
  border-left: 3px solid var(--clr-success);
  border-radius: var(--radius-md);
  font-size: var(--fs-sm);
  font-weight: var(--fw-medium);
  box-shadow: var(--shadow-lg);
  pointer-events: auto;
  animation: toastIn var(--dur-base) var(--ease-spring);
  max-width: 340px;
}
.toast--error { border-left-color: var(--clr-danger); }
.toast__close {
  margin-left: auto;
  color: var(--clr-text-sub);
  font-size: var(--fs-xs);
  padding: 2px 6px;
  flex-shrink: 0;
}
.toast__close:hover { color: var(--clr-text); }
 
@keyframes toastIn {
  from { opacity: 0; transform: translateX(20px); }
  to   { opacity: 1; transform: translateX(0); }
}
 
/* ================================================================
   18. THEME ICON
   ================================================================ */
.theme-icon { font-style: normal; font-size: 1.1rem; }
 
/* ================================================================
   19. RESPONSIVE BREAKPOINTS
   ================================================================ */
@media (max-width: 640px) {
  /* Nav */
  .nav__links { display: none; }
  .nav__hamburger { display: flex; }
 
  /* Hero */
  .hero__cta-group { flex-direction: column; align-items: flex-start; }
  .hero__stats { gap: var(--sp-5); }
 
  /* Footer */
  .site-footer__inner { flex-direction: column; align-items: flex-start; gap: var(--sp-4); }
}
 
@media (max-width: 480px) {
  /* Toolbar */
  .catalog__toolbar { flex-direction: column; }
  .search-field { max-width: 100%; min-width: 0; }
 
  /* Modal title */
  .modal__title { font-size: var(--fs-lg); }
}
 
/* ================================================================
   20. SCROLLBAR
   ================================================================ */
::-webkit-scrollbar { width: 6px; height: 6px; }
::-webkit-scrollbar-track { background: var(--clr-bg); }
::-webkit-scrollbar-thumb { background: var(--clr-border); border-radius: 3px; }
::-webkit-scrollbar-thumb:hover { background: var(--clr-text-sub); }
 
/* ================================================================
   21. SELECTION
   ================================================================ */
::selection { background: color-mix(in srgb, var(--clr-accent) 25%, transparent); }
 
/* ================================================================
   SKELETON LOADING — API хүлээх үеийн animation
   ================================================================ */
.skeleton-box,
.skeleton-line {
  background: linear-gradient(
    90deg,
    var(--clr-card) 25%,
    var(--clr-border) 50%,
    var(--clr-card) 75%
  );
  background-size: 200% 100%;
  animation: shimmer 1.4s infinite;
  border-radius: var(--radius-sm);
}
.book-card--skeleton .book-card__cover { font-size: 0; }
.book-card--skeleton                   { pointer-events: none; }
@keyframes shimmer {
  from { background-position: 200% 0; }
  to   { background-position: -200% 0; }
}
 
/* ================================================================
   BOOK COVER IMAGE
   ================================================================ */
book-card__img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: center;
  display: block;
  position: absolute;
  inset: 0;
}