/* ==========================================================================
   Loable Books - Responsive Styles
   Mobile-first approach
   ========================================================================== */

/* --------------------------------------------------------------------------
   Breakpoints:
   - sm: 640px
   - md: 768px
   - lg: 1024px
   - xl: 1280px
   -------------------------------------------------------------------------- */

/* --------------------------------------------------------------------------
   Mobile Base (< 640px)
   -------------------------------------------------------------------------- */

/* Typography adjustments for mobile */
h1 {
  font-size: var(--font-size-2xl);
}

h2 {
  font-size: var(--font-size-xl);
}

h3 {
  font-size: var(--font-size-lg);
}

/* Container padding */
.container {
  padding: 0 var(--space-4);
}

/* Section spacing */
.section {
  padding: var(--space-10) 0;
}

/* Grid defaults to single column */
.grid-2,
.grid-3,
.grid-4 {
  grid-template-columns: 1fr;
}

/* --------------------------------------------------------------------------
   Header - Mobile
   -------------------------------------------------------------------------- */
.header {
  position: sticky;
  top: 0;
  z-index: var(--z-sticky);
  background: var(--color-bg);
  border-bottom: 1px solid var(--color-border);
}

.header__container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--space-3) var(--space-4);
}

.header__logo {
  display: flex;
  align-items: center;
  gap: var(--space-2);
}

.header__logo-img {
  height: 36px;
  width: auto;
}

.header__logo-text {
  font-family: var(--font-heading);
  font-size: var(--font-size-lg);
  font-weight: 700;
  color: var(--color-primary);
}

.header__actions {
  display: flex;
  align-items: center;
  gap: var(--space-2);
}

/* Mobile menu toggle */
.menu-toggle {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 44px;
  height: 44px;
  background: none;
  border: none;
  cursor: pointer;
  color: var(--color-text);
}

.menu-toggle__icon {
  width: 24px;
  height: 24px;
}

/* Mobile navigation */
.nav {
  position: fixed;
  top: 0;
  right: 0;
  bottom: 0;
  width: 300px;
  max-width: 85vw;
  background: var(--color-bg);
  box-shadow: var(--shadow-xl);
  transform: translateX(100%);
  transition: transform var(--transition-slow);
  z-index: var(--z-modal);
  overflow-y: auto;
}

.nav.is-open {
  transform: translateX(0);
}

.nav__header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--space-4);
  border-bottom: 1px solid var(--color-border);
}

.nav__close {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 44px;
  height: 44px;
  background: none;
  border: none;
  cursor: pointer;
  color: var(--color-text);
}

.nav__list {
  list-style: none;
  padding: var(--space-4);
}

.nav__item {
  margin-bottom: var(--space-1);
}

.nav__link {
  display: block;
  padding: var(--space-3) var(--space-4);
  font-weight: 500;
  color: var(--color-text);
  border-radius: var(--radius);
  transition: background-color var(--transition-fast);
}

.nav__link:hover {
  background-color: var(--color-bg-alt);
  color: var(--color-primary);
}

.nav__link.is-active {
  background-color: var(--color-primary);
  color: white;
}

/* Dropdown submenu */
.nav__dropdown {
  list-style: none;
  padding-left: var(--space-4);
  max-height: 0;
  overflow: hidden;
  transition: max-height var(--transition-slow);
}

.nav__item.is-expanded .nav__dropdown {
  max-height: 500px;
}

.nav__dropdown-link {
  display: block;
  padding: var(--space-2) var(--space-4);
  font-size: var(--font-size-sm);
  color: var(--color-text-light);
}

.nav__dropdown-link:hover {
  color: var(--color-primary);
}

/* Overlay */
.nav-overlay {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.5);
  opacity: 0;
  visibility: hidden;
  transition: opacity var(--transition-base), visibility var(--transition-base);
  z-index: calc(var(--z-modal) - 1);
}

.nav-overlay.is-visible {
  opacity: 1;
  visibility: visible;
}

/* Desktop search hidden on mobile */
.header__search {
  display: none;
}

/* --------------------------------------------------------------------------
   Hero - Mobile
   -------------------------------------------------------------------------- */
.hero {
  padding: var(--space-10) 0;
  background-color: var(--color-bg-alt);
}

.hero__content {
  text-align: center;
  margin-bottom: var(--space-8);
}

.hero__title {
  font-size: var(--font-size-2xl);
  margin-bottom: var(--space-4);
}

.hero__subtitle {
  font-size: var(--font-size-base);
  color: var(--color-text-light);
  margin-bottom: var(--space-6);
}

.hero__image {
  max-width: 280px;
  margin: 0 auto;
}

.hero__image img {
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-lg);
}

/* --------------------------------------------------------------------------
   Book Detail Page - Mobile
   -------------------------------------------------------------------------- */
.book-detail {
  padding: var(--space-8) 0;
}

.book-detail__cover {
  max-width: 300px;
  margin: 0 auto var(--space-8);
}

.book-detail__cover img {
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-lg);
}

.book-detail__info {
  text-align: center;
}

.book-detail__title {
  font-size: var(--font-size-2xl);
  margin-bottom: var(--space-4);
}

.book-detail__subtitle {
  display: block;
  font-size: var(--font-size-lg);
  color: var(--color-text-light);
  font-weight: 400;
  margin-top: var(--space-3);
  line-height: var(--line-height-base);
}

.book-detail__meta {
  margin: var(--space-6) 0;
  text-align: left;
}

.book-detail__description {
  text-align: left;
  line-height: var(--line-height-relaxed);
  margin-bottom: var(--space-4);
}

.book-detail__description[data-expandable] [data-expandable-content] {
  overflow: hidden;
  transition: max-height 0.3s ease;
}

.book-detail__description[data-expandable] [data-expandable-content].is-collapsed {
  position: relative;
}

.book-detail__description[data-expandable] [data-expandable-content].is-collapsed::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  height: 60px;
  background: linear-gradient(transparent, var(--color-bg));
  pointer-events: none;
}

.book-detail__description [data-expandable-toggle] {
  position: relative;
  z-index: 1;
}

/* --------------------------------------------------------------------------
   Footer - Mobile
   -------------------------------------------------------------------------- */
.footer {
  background-color: var(--color-primary-dark);
  color: white;
  padding: var(--space-12) 0 var(--space-6);
}

.footer__grid {
  display: grid;
  gap: var(--space-8);
}

.footer__section-title {
  font-size: var(--font-size-base);
  font-weight: 600;
  margin-bottom: var(--space-4);
  color: white;
}

.footer__list {
  list-style: none;
  padding: 0;
}

.footer__link {
  display: block;
  padding: var(--space-2) 0;
  color: rgba(255, 255, 255, 0.7);
  transition: color var(--transition-fast);
}

.footer__link:hover {
  color: white;
}

.footer__social {
  display: flex;
  gap: var(--space-4);
}

.footer__social-link {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  background: rgba(255, 255, 255, 0.1);
  border-radius: 50%;
  color: white;
  transition: background-color var(--transition-fast);
}

.footer__social-link:hover {
  background: rgba(255, 255, 255, 0.2);
  color: white;
}

.footer__bottom {
  margin-top: var(--space-10);
  padding-top: var(--space-6);
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  text-align: center;
  font-size: var(--font-size-sm);
  color: rgba(255, 255, 255, 0.6);
}

.footer__bottom-links {
  display: flex;
  justify-content: center;
  gap: var(--space-4);
  margin-top: var(--space-3);
}

.footer__bottom-link {
  color: rgba(255, 255, 255, 0.6);
}

.footer__bottom-link:hover {
  color: white;
}

/* --------------------------------------------------------------------------
   Small devices (sm: 640px and up)
   -------------------------------------------------------------------------- */
@media (min-width: 640px) {
  h1 {
    font-size: var(--font-size-3xl);
  }

  h2 {
    font-size: var(--font-size-2xl);
  }

  .grid-2 {
    grid-template-columns: repeat(2, 1fr);
  }

  .hero__title {
    font-size: var(--font-size-3xl);
  }

  .footer__grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

/* --------------------------------------------------------------------------
   Medium devices (md: 768px and up)
   -------------------------------------------------------------------------- */
@media (min-width: 768px) {
  .container {
    padding: 0 var(--space-6);
  }

  .section {
    padding: var(--space-16) 0;
  }

  .grid-3 {
    grid-template-columns: repeat(3, 1fr);
  }

  .hero {
    padding: var(--space-16) 0;
  }

  .hero__container {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--space-10);
    align-items: center;
  }

  .hero__content {
    text-align: left;
    margin-bottom: 0;
    order: 1;
  }

  .hero__image {
    order: 2;
    max-width: 100%;
  }

  .hero__title {
    font-size: var(--font-size-4xl);
  }

  /* Book detail layout */
  .book-detail__container {
    display: grid;
    grid-template-columns: 350px 1fr;
    gap: var(--space-10);
    align-items: start;
  }

  .book-detail__cover {
    position: sticky;
    top: 100px;
    margin: 0;
    max-width: 100%;
  }

  .book-detail__info {
    text-align: left;
  }

  .footer__grid {
    grid-template-columns: repeat(3, 1fr);
  }
}

/* --------------------------------------------------------------------------
   Large devices (lg: 1024px and up)
   -------------------------------------------------------------------------- */
@media (min-width: 1024px) {
  h1 {
    font-size: var(--font-size-4xl);
  }

  h2 {
    font-size: var(--font-size-3xl);
  }

  .grid-4 {
    grid-template-columns: repeat(4, 1fr);
  }

  /* Desktop navigation */
  .menu-toggle {
    display: none;
  }

  .nav {
    position: static;
    width: auto;
    max-width: none;
    background: transparent;
    box-shadow: none;
    transform: none;
    overflow: visible;
  }

  .nav__header,
  .nav__close {
    display: none;
  }

  .nav__list {
    display: flex;
    align-items: center;
    gap: var(--space-1);
    padding: 0;
  }

  .nav__item {
    position: relative;
    margin-bottom: 0;
  }

  .nav__link {
    padding: var(--space-2) var(--space-4);
  }

  /* Desktop dropdown */
  .nav__dropdown {
    position: absolute;
    top: 100%;
    left: 0;
    min-width: 200px;
    background: var(--color-bg);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-lg);
    padding: var(--space-2);
    opacity: 0;
    visibility: hidden;
    transform: translateY(10px);
    transition: all var(--transition-base);
  }

  .nav__item:hover .nav__dropdown {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
    max-height: none;
  }

  .nav__dropdown-link {
    padding: var(--space-2) var(--space-3);
    border-radius: var(--radius);
  }

  .nav__dropdown-link:hover {
    background-color: var(--color-bg-alt);
  }

  .nav-overlay {
    display: none;
  }

  /* Desktop header layout */
  .header__container {
    padding: var(--space-4) var(--space-6);
  }

  .header__search {
    display: block;
    flex: 1;
    max-width: 400px;
    margin: 0 var(--space-8);
  }

  .hero__title {
    font-size: var(--font-size-5xl);
  }

  .hero__subtitle {
    font-size: var(--font-size-lg);
  }

  .book-detail__container {
    grid-template-columns: 400px 1fr;
    gap: var(--space-16);
  }

  .footer__grid {
    grid-template-columns: 2fr 1fr 1fr 1fr;
  }

  .footer__bottom {
    display: flex;
    justify-content: space-between;
    align-items: center;
    text-align: left;
  }

  .footer__bottom-links {
    margin-top: 0;
  }
}

/* --------------------------------------------------------------------------
   Extra large devices (xl: 1280px and up)
   -------------------------------------------------------------------------- */
@media (min-width: 1280px) {
  .container {
    padding: 0 var(--space-8);
  }

  h1 {
    font-size: var(--font-size-5xl);
  }
}

/* --------------------------------------------------------------------------
   Print Styles
   -------------------------------------------------------------------------- */
@media print {
  .header,
  .footer,
  .nav,
  .menu-toggle,
  .btn,
  .purchase-buttons {
    display: none !important;
  }

  body {
    font-size: 12pt;
    color: black;
    background: white;
  }

  a {
    color: black;
    text-decoration: underline;
  }

  .container {
    max-width: 100%;
    padding: 0;
  }
}

/* --------------------------------------------------------------------------
   Reduced Motion
   -------------------------------------------------------------------------- */
@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }

  html {
    scroll-behavior: auto;
  }
}