/* ===== DESIGN TOKENS ===== */
:root {
  /* Type Scale */
  --text-xs: clamp(0.75rem, 0.7rem + 0.25vw, 0.875rem);
  --text-sm: clamp(0.875rem, 0.8rem + 0.35vw, 1rem);
  --text-base: clamp(1rem, 0.95rem + 0.25vw, 1.125rem);
  --text-lg: clamp(1.125rem, 1rem + 0.75vw, 1.5rem);
  --text-xl: clamp(1.5rem, 1.2rem + 1.25vw, 2.25rem);
  --text-2xl: clamp(2rem, 1.2rem + 2.5vw, 3.5rem);
  --text-3xl: clamp(2.5rem, 1rem + 4vw, 5rem);

  /* Spacing */
  --space-1: 0.25rem;
  --space-2: 0.5rem;
  --space-3: 0.75rem;
  --space-4: 1rem;
  --space-5: 1.25rem;
  --space-6: 1.5rem;
  --space-8: 2rem;
  --space-10: 2.5rem;
  --space-12: 3rem;
  --space-16: 4rem;
  --space-20: 5rem;
  --space-24: 6rem;
  --space-32: 8rem;

  /* Radius */
  --radius-sm: 0.375rem;
  --radius-md: 0.5rem;
  --radius-lg: 0.75rem;
  --radius-xl: 1rem;
  --radius-full: 9999px;

  /* Transitions */
  --transition-interactive: 180ms cubic-bezier(0.16, 1, 0.3, 1);

  /* Content widths */
  --content-narrow: 640px;
  --content-default: 960px;
  --content-wide: 1200px;
  --content-full: 100%;

  /* Fonts */
  --font-display: 'Special Elite', 'Courier New', monospace;
  --font-body: 'Work Sans', 'Helvetica Neue', sans-serif;
}

/* ===== LIGHT MODE (warm cream/editorial) ===== */
:root,
[data-theme='light'] {
  --color-bg: #FAF8F5;
  --color-surface: #FFFFFF;
  --color-surface-2: #F5F2ED;
  --color-surface-offset: #EDE9E3;
  --color-divider: #DDD8D0;
  --color-border: #CCC7BF;
  --color-text: #1A1A1A;
  --color-text-muted: #6B6560;
  --color-text-faint: #A09A94;
  --color-text-inverse: #FAF8F5;
  --color-primary: #2C2C2C;
  --color-primary-hover: #1A1A1A;
  --color-accent: #C0392B;
  --color-accent-hover: #A83228;
  --shadow-sm: 0 1px 3px rgba(0,0,0,0.06);
  --shadow-md: 0 4px 12px rgba(0,0,0,0.08);
  --shadow-lg: 0 12px 32px rgba(0,0,0,0.12);
  --shadow-book: 0 8px 24px rgba(0,0,0,0.15), 0 2px 6px rgba(0,0,0,0.08);
}

/* ===== DARK MODE ===== */
[data-theme='dark'] {
  --color-bg: #141210;
  --color-surface: #1E1C18;
  --color-surface-2: #262420;
  --color-surface-offset: #1A1816;
  --color-divider: #2E2C28;
  --color-border: #3A3834;
  --color-text: #E8E4DE;
  --color-text-muted: #9A958E;
  --color-text-faint: #5E5A54;
  --color-text-inverse: #141210;
  --color-primary: #E8E4DE;
  --color-primary-hover: #FFFFFF;
  --color-accent: #E74C3C;
  --color-accent-hover: #FF6B5E;
  --shadow-sm: 0 1px 3px rgba(0,0,0,0.3);
  --shadow-md: 0 4px 12px rgba(0,0,0,0.4);
  --shadow-lg: 0 12px 32px rgba(0,0,0,0.5);
  --shadow-book: 0 8px 24px rgba(0,0,0,0.4), 0 2px 6px rgba(0,0,0,0.3);
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme]) {
    --color-bg: #141210;
    --color-surface: #1E1C18;
    --color-surface-2: #262420;
    --color-surface-offset: #1A1816;
    --color-divider: #2E2C28;
    --color-border: #3A3834;
    --color-text: #E8E4DE;
    --color-text-muted: #9A958E;
    --color-text-faint: #5E5A54;
    --color-text-inverse: #141210;
    --color-primary: #E8E4DE;
    --color-primary-hover: #FFFFFF;
    --color-accent: #E74C3C;
    --color-accent-hover: #FF6B5E;
    --shadow-sm: 0 1px 3px rgba(0,0,0,0.3);
    --shadow-md: 0 4px 12px rgba(0,0,0,0.4);
    --shadow-lg: 0 12px 32px rgba(0,0,0,0.5);
    --shadow-book: 0 8px 24px rgba(0,0,0,0.4), 0 2px 6px rgba(0,0,0,0.3);
  }
}

/* ===== GLOBAL STYLES ===== */
body {
  font-family: var(--font-body);
  overflow-x: hidden;
}

h1, h2, h3 {
  font-family: var(--font-display);
  letter-spacing: 0.02em;
}

a {
  color: var(--color-accent);
  text-decoration: none;
}
a:hover {
  color: var(--color-accent-hover);
}

.container {
  max-width: var(--content-wide);
  margin-inline: auto;
  padding-inline: var(--space-4);
}

@media (min-width: 768px) {
  .container {
    padding-inline: var(--space-8);
  }
}

/* ===== HEADER ===== */
.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: oklch(from var(--color-bg) l c h / 0.92);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--color-divider);
  transition: box-shadow 0.3s ease;
}
.site-header.scrolled {
  box-shadow: var(--shadow-sm);
}
.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-block: var(--space-3);
  max-width: var(--content-wide);
  margin-inline: auto;
  padding-inline: var(--space-4);
}
@media (min-width: 768px) {
  .header-inner {
    padding-inline: var(--space-8);
  }
}
.header-logo {
  display: flex;
  align-items: center;
  gap: var(--space-3);
}
.header-logo img {
  height: 40px;
  width: auto;
  border-radius: var(--radius-sm);
}
.header-logo-text {
  font-family: var(--font-display);
  font-size: var(--text-lg);
  color: var(--color-text);
  line-height: 1.1;
}
.header-nav {
  display: flex;
  align-items: center;
  gap: var(--space-4);
}
.header-nav a {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  text-decoration: none;
  padding: var(--space-1) var(--space-2);
}
.header-nav a:hover {
  color: var(--color-text);
}
.header-controls {
  display: flex;
  align-items: center;
  gap: var(--space-2);
}

.btn-lang, .btn-theme {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  border-radius: var(--radius-full);
  background: var(--color-surface-2);
  color: var(--color-text-muted);
  font-size: var(--text-xs);
  font-weight: 600;
  font-family: var(--font-body);
  border: 1px solid var(--color-divider);
  cursor: pointer;
}
.btn-lang:hover, .btn-theme:hover {
  background: var(--color-surface-offset);
  color: var(--color-text);
}

/* Mobile nav */
.mobile-menu-btn {
  display: none;
  width: 36px;
  height: 36px;
  align-items: center;
  justify-content: center;
  color: var(--color-text);
}
.mobile-nav {
  display: none;
}
@media (max-width: 767px) {
  .header-nav {
    display: none;
  }
  .mobile-menu-btn {
    display: inline-flex;
  }
  .mobile-nav {
    display: flex;
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: var(--color-bg);
    z-index: 100;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: var(--space-8);
    opacity: 0;
    pointer-events: none;
    transition: opacity 0.3s ease;
  }
  .mobile-nav.open {
    opacity: 1;
    pointer-events: auto;
  }
  .mobile-nav a {
    font-family: var(--font-display);
    font-size: var(--text-xl);
    color: var(--color-text);
    text-decoration: none;
  }
  .mobile-nav-close {
    position: absolute;
    top: var(--space-4);
    right: var(--space-4);
    width: 44px;
    height: 44px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--color-text);
    font-size: 1.5rem;
  }
}

/* ===== HERO ===== */
.hero {
  padding-block: clamp(var(--space-12), 8vw, var(--space-24));
  text-align: center;
  overflow: hidden;
}
.hero-tagline {
  font-family: var(--font-body);
  font-size: var(--text-sm);
  text-transform: uppercase;
  letter-spacing: 0.15em;
  color: var(--color-text-muted);
  margin-bottom: var(--space-4);
}
.hero h1 {
  font-size: var(--text-3xl);
  color: var(--color-text);
  margin-bottom: var(--space-4);
  max-width: 16ch;
  margin-inline: auto;
}
.hero-subtitle {
  font-size: var(--text-base);
  color: var(--color-text-muted);
  max-width: 50ch;
  margin-inline: auto;
  margin-bottom: var(--space-8);
  line-height: 1.7;
}
.hero-illustration {
  max-width: 900px;
  margin-inline: auto;
  margin-top: var(--space-8);
  border-radius: var(--radius-lg);
  overflow: hidden;
}
.hero-illustration img {
  width: 100%;
  height: auto;
}
.hero-cta-group {
  display: flex;
  gap: var(--space-4);
  justify-content: center;
  flex-wrap: wrap;
}

/* Buttons */
.btn-primary {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  padding: var(--space-3) var(--space-6);
  background: var(--color-primary);
  color: var(--color-text-inverse);
  font-family: var(--font-body);
  font-size: var(--text-sm);
  font-weight: 600;
  border-radius: var(--radius-md);
  text-decoration: none;
  border: none;
  cursor: pointer;
}
.btn-primary:hover {
  background: var(--color-primary-hover);
  color: var(--color-text-inverse);
}
.btn-secondary {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  padding: var(--space-3) var(--space-6);
  background: transparent;
  color: var(--color-text);
  font-family: var(--font-body);
  font-size: var(--text-sm);
  font-weight: 600;
  border-radius: var(--radius-md);
  border: 1px solid var(--color-border);
  text-decoration: none;
  cursor: pointer;
}
.btn-secondary:hover {
  background: var(--color-surface-2);
  border-color: var(--color-text-muted);
}

/* ===== BOOKS SECTION ===== */
.section {
  padding-block: clamp(var(--space-12), 6vw, var(--space-20));
}
.section-header {
  text-align: center;
  margin-bottom: clamp(var(--space-8), 4vw, var(--space-12));
}
.section-header h2 {
  font-size: var(--text-2xl);
  color: var(--color-text);
  margin-bottom: var(--space-3);
}
.section-header p {
  font-size: var(--text-base);
  color: var(--color-text-muted);
  max-width: 50ch;
  margin-inline: auto;
}

/* Book grid */
.books-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(min(280px, 100%), 1fr));
  gap: var(--space-6);
}
.book-card {
  background: var(--color-surface);
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow-sm);
  transition: transform 0.3s ease, box-shadow 0.3s ease;
}
.book-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
}
.book-cover-wrapper {
  position: relative;
  aspect-ratio: 2/3;
  overflow: hidden;
  background: var(--color-surface-2);
}
.book-cover-wrapper img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}
.book-badge {
  position: absolute;
  top: var(--space-3);
  right: var(--space-3);
  background: var(--color-primary);
  color: var(--color-text-inverse);
  font-size: var(--text-xs);
  font-weight: 600;
  padding: var(--space-1) var(--space-2);
  border-radius: var(--radius-sm);
}
.book-info {
  padding: var(--space-4);
}
.book-title {
  font-family: var(--font-display);
  font-size: var(--text-lg);
  color: var(--color-text);
  margin-bottom: var(--space-2);
  line-height: 1.3;
}
.book-desc {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  margin-bottom: var(--space-3);
  line-height: 1.5;
}
.book-price {
  font-size: var(--text-sm);
  font-weight: 600;
  color: var(--color-text);
}
.book-price span {
  color: var(--color-text-muted);
  font-weight: 400;
}
.book-links {
  display: flex;
  gap: var(--space-2);
  margin-top: var(--space-3);
}
.book-links a {
  font-size: var(--text-xs);
  color: var(--color-accent);
  text-decoration: none;
  padding: var(--space-1) var(--space-2);
  border: 1px solid var(--color-accent);
  border-radius: var(--radius-sm);
}
.book-links a:hover {
  background: var(--color-accent);
  color: #fff;
}

/* Language tabs for book display */
.lang-tabs {
  display: flex;
  justify-content: center;
  gap: var(--space-2);
  margin-bottom: var(--space-8);
}
.lang-tab {
  padding: var(--space-2) var(--space-5);
  border-radius: var(--radius-full);
  font-size: var(--text-sm);
  font-weight: 600;
  cursor: pointer;
  background: var(--color-surface-2);
  color: var(--color-text-muted);
  border: 1px solid var(--color-divider);
}
.lang-tab.active {
  background: var(--color-primary);
  color: var(--color-text-inverse);
  border-color: var(--color-primary);
}
.lang-tab:hover:not(.active) {
  background: var(--color-surface-offset);
  color: var(--color-text);
}

/* ===== READING SAMPLE / EXCERPT ===== */
.excerpt-section {
  background: var(--color-surface-2);
}
.excerpt-card {
  max-width: var(--content-narrow);
  margin-inline: auto;
  background: var(--color-surface);
  border-radius: var(--radius-xl);
  padding: clamp(var(--space-6), 4vw, var(--space-12));
  box-shadow: var(--shadow-md);
  position: relative;
}
.excerpt-quote {
  position: absolute;
  top: -0.3em;
  left: var(--space-4);
  font-family: var(--font-display);
  font-size: clamp(4rem, 10vw, 8rem);
  color: var(--color-divider);
  line-height: 1;
  pointer-events: none;
}
.excerpt-text {
  font-size: var(--text-base);
  color: var(--color-text);
  line-height: 1.8;
  font-style: italic;
  position: relative;
  z-index: 1;
}
.excerpt-source {
  margin-top: var(--space-4);
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  font-style: normal;
  text-align: right;
}

/* ===== ABOUT SECTION ===== */
.about-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-8);
  align-items: center;
}
@media (min-width: 768px) {
  .about-grid {
    grid-template-columns: 1fr 1.4fr;
    gap: var(--space-12);
  }
}
.about-image {
  max-width: 360px;
  margin-inline: auto;
}
.about-image img {
  width: 100%;
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-md);
}
.about-content h2 {
  font-size: var(--text-2xl);
  margin-bottom: var(--space-4);
}
.about-content p {
  font-size: var(--text-base);
  color: var(--color-text-muted);
  line-height: 1.7;
  margin-bottom: var(--space-4);
}
.about-content p:last-of-type {
  margin-bottom: 0;
}

/* ===== NEWSLETTER ===== */
.newsletter-section {
  background: var(--color-primary);
  color: var(--color-text-inverse);
}
.newsletter-section h2 {
  color: var(--color-text-inverse);
}
.newsletter-section p {
  color: oklch(from var(--color-text-inverse) l c h / 0.7);
}
.newsletter-form {
  display: flex;
  gap: var(--space-3);
  max-width: 480px;
  margin-inline: auto;
  margin-top: var(--space-6);
}
.newsletter-form input {
  flex: 1;
  padding: var(--space-3) var(--space-4);
  border-radius: var(--radius-md);
  border: 1px solid oklch(from var(--color-text-inverse) l c h / 0.3);
  background: oklch(from var(--color-text-inverse) l c h / 0.1);
  color: var(--color-text-inverse);
  font-size: var(--text-sm);
}
.newsletter-form input::placeholder {
  color: oklch(from var(--color-text-inverse) l c h / 0.5);
}
.newsletter-form button {
  padding: var(--space-3) var(--space-5);
  background: var(--color-text-inverse);
  color: var(--color-primary);
  font-weight: 600;
  font-size: var(--text-sm);
  border-radius: var(--radius-md);
  border: none;
  cursor: pointer;
  white-space: nowrap;
}
.newsletter-form button:hover {
  opacity: 0.9;
}

@media (max-width: 480px) {
  .newsletter-form {
    flex-direction: column;
  }
}

/* ===== FOOTER ===== */
.site-footer {
  border-top: 1px solid var(--color-divider);
  padding-block: var(--space-8);
}
.footer-inner {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--space-4);
  text-align: center;
}
@media (min-width: 768px) {
  .footer-inner {
    flex-direction: row;
    justify-content: space-between;
    text-align: left;
  }
}
.footer-copy {
  font-size: var(--text-xs);
  color: var(--color-text-muted);
}
.footer-links {
  display: flex;
  gap: var(--space-4);
}
.footer-links a {
  font-size: var(--text-xs);
  color: var(--color-text-muted);
  text-decoration: none;
}
.footer-links a:hover {
  color: var(--color-text);
}

/* ===== SCROLL ANIMATIONS ===== */
.reveal {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}
.reveal.visible {
  opacity: 1;
  transform: translateY(0);
}

/* ===== SERIES DIVIDER ===== */
.series-divider {
  display: flex;
  align-items: center;
  gap: var(--space-4);
  margin-block: var(--space-8);
}
.series-divider::before,
.series-divider::after {
  content: '';
  flex: 1;
  height: 1px;
  background: var(--color-divider);
}
.series-divider span {
  font-family: var(--font-display);
  font-size: var(--text-xs);
  color: var(--color-text-faint);
  text-transform: uppercase;
  letter-spacing: 0.15em;
  white-space: nowrap;
}

/* ===== SERIES BADGES ===== */
.book-color-badge {
  width: 8px;
  height: 8px;
  border-radius: var(--radius-full);
  display: inline-block;
  margin-right: var(--space-1);
  vertical-align: middle;
}