/* Design tokens */
:root {
  --color-bg: #0a1628;
  --color-bg-alt: #0f1f35;
  --color-surface: #132a45;
  --color-surface-alt: #1a3554;
  --color-text: #e8eef5;
  --color-heading: #e8eef5;
  --color-text-muted: #9eb3c9;
  --color-accent: #f4a261;
  --color-accent-hover: #f7b87a;
  --color-teal: #1a6b7a;
  --color-teal-light: #2a8f9e;
  --color-border: rgba(158, 179, 201, 0.2);
  --font-sans: "Noto Sans KR", -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  --max-width: 72rem;
  --header-height: 4rem;
  --radius: 0.75rem;
  --radius-lg: 1.25rem;
  --shadow: 0 8px 32px rgba(0, 0, 0, 0.35);
  --shadow-sm: 0 4px 16px rgba(0, 0, 0, 0.25);
  --transition: 0.25s ease;
  --space-xs: 0.5rem;
  --space-sm: 1rem;
  --space-md: 1.5rem;
  --space-lg: 2.5rem;
  --space-xl: 4rem;
  --space-2xl: 6rem;
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}

body {
  margin: 0;
  font-family: var(--font-sans);
  font-size: 1rem;
  line-height: 1.7;
  color: var(--color-text);
  background: var(--color-bg);
  -webkit-font-smoothing: antialiased;
}

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

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

a:hover {
  color: var(--color-accent-hover);
}

a:focus-visible,
button:focus-visible,
summary:focus-visible {
  outline: 2px solid var(--color-accent);
  outline-offset: 3px;
}

.skip-link {
  position: absolute;
  top: -100%;
  left: var(--space-sm);
  z-index: 200;
  padding: var(--space-xs) var(--space-sm);
  background: var(--color-accent);
  color: var(--color-bg);
  border-radius: var(--radius);
  font-weight: 600;
}

.skip-link:focus {
  top: var(--space-sm);
}

.container {
  width: 100%;
  max-width: var(--max-width);
  margin-inline: auto;
  padding-inline: var(--space-md);
}

/* Header */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  height: var(--header-height);
  background: rgba(10, 22, 40, 0.85);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid transparent;
  transition: border-color var(--transition), box-shadow var(--transition);
}

.site-header.is-scrolled {
  border-color: var(--color-border);
  box-shadow: var(--shadow-sm);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: var(--header-height);
}

.logo {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 0.35rem;
  font-weight: 700;
  font-size: 0.95rem;
  line-height: 1.3;
  min-width: 0;
}

.site-header .logo a:link,
.site-header .logo a:visited {
  color: var(--color-text-muted);
  white-space: nowrap;
}

.site-header .logo a:hover {
  color: var(--color-accent);
}

.site-header .logo-sep {
  color: var(--color-text-muted);
  font-weight: 500;
  user-select: none;
}

@media (max-width: 480px) {
  .logo {
    font-size: 0.8rem;
    gap: 0.25rem;
  }
}

.nav-toggle {
  display: flex;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 2.5rem;
  height: 2.5rem;
  padding: 0;
  border: none;
  background: transparent;
  cursor: pointer;
}

.nav-toggle-bar {
  display: block;
  width: 100%;
  height: 2px;
  background: var(--color-text);
  border-radius: 1px;
  transition: transform var(--transition), opacity var(--transition);
}

.nav-toggle[aria-expanded="true"] .nav-toggle-bar:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
}

.nav-toggle[aria-expanded="true"] .nav-toggle-bar:nth-child(2) {
  opacity: 0;
}

.nav-toggle[aria-expanded="true"] .nav-toggle-bar:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
}

.site-nav {
  display: none;
}

.site-nav.is-open {
  display: block;
  position: absolute;
  top: var(--header-height);
  left: 0;
  right: 0;
  background: rgba(10, 22, 40, 0.98);
  border-bottom: 1px solid var(--color-border);
  padding: var(--space-sm) var(--space-md) var(--space-md);
}

.site-nav ul {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: var(--space-xs);
}

.site-nav a {
  display: block;
  padding: var(--space-xs) 0;
  color: var(--color-text-muted);
  font-weight: 500;
}

.site-nav a:hover,
.site-nav a.is-active {
  color: var(--color-accent);
}

.nav-cta {
  color: var(--color-accent) !important;
  font-weight: 600 !important;
}

.nav-pageviews {
  margin-top: var(--space-xs);
}

.pageviews-badge {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  padding: 0.35rem 0.65rem;
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--color-teal-light);
  background: rgba(26, 107, 122, 0.2);
  border: 1px solid var(--color-border);
  border-radius: 999px;
  line-height: 1;
}

.pageviews-icon {
  display: inline-flex;
  flex-shrink: 0;
  opacity: 0.85;
}

.pageviews-count {
  font-variant-numeric: tabular-nums;
  min-width: 1.25rem;
  text-align: center;
}

.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

@media (min-width: 768px) {
  .nav-toggle {
    display: none;
  }

  .site-nav {
    display: block;
    position: static;
    background: transparent;
    border: none;
    padding: 0;
  }

  .site-nav ul {
    flex-direction: row;
    align-items: center;
    gap: var(--space-md);
  }

  .site-nav a {
    padding: 0;
    font-size: 0.9rem;
  }

  .nav-pageviews {
    margin-top: 0;
  }
}

/* Sections */
.section {
  padding-block: var(--space-xl);
}

.section-alt {
  background: var(--color-bg-alt);
}

.section-header {
  text-align: center;
  margin-bottom: var(--space-lg);
}

.section-header h2 {
  margin: 0 0 var(--space-sm);
  font-size: clamp(1.75rem, 4vw, 2.25rem);
  font-weight: 700;
  letter-spacing: -0.02em;
  color: var(--color-heading);
}

.section-lead {
  margin: 0;
  color: var(--color-text-muted);
  font-size: 1.1rem;
  max-width: 40rem;
  margin-inline: auto;
}

/* Reveal animation */
.reveal {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

.reveal.is-visible {
  opacity: 1;
  transform: translateY(0);
}

/* Hero */
.hero {
  position: relative;
  min-height: calc(100vh - var(--header-height));
  display: flex;
  align-items: center;
  padding-block: var(--space-xl);
  overflow: hidden;
}

.hero-bg {
  position: absolute;
  inset: 0;
  background:
    radial-gradient(ellipse 80% 50% at 20% 40%, rgba(26, 107, 122, 0.35), transparent),
    radial-gradient(ellipse 60% 40% at 80% 80%, rgba(244, 162, 97, 0.12), transparent),
    linear-gradient(180deg, var(--color-bg) 0%, var(--color-bg-alt) 100%);
  pointer-events: none;
}

.hero-grid {
  position: relative;
  display: grid;
  gap: var(--space-lg);
  align-items: center;
}

.hero-visual {
  display: flex;
  justify-content: center;
  will-change: transform;
}

.book-cover-wrap {
  position: relative;
  width: min(280px, 75vw);
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow);
  border: 1px solid var(--color-border);
}

.book-cover-wrap.book-cover--fallback {
  aspect-ratio: 959 / 1200;
}

.book-cover {
  display: block;
  width: 100%;
  height: auto;
  object-fit: contain;
}

.book-cover-fallback {
  position: absolute;
  inset: 0;
  display: none;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: var(--space-md);
  background: linear-gradient(145deg, var(--color-teal) 0%, var(--color-surface) 50%, var(--color-bg) 100%);
}

.book-cover-wrap.book-cover--fallback .book-cover {
  display: none;
}

.book-cover-wrap.book-cover--fallback .book-cover-fallback {
  display: flex;
}

.fallback-title {
  font-size: 1.5rem;
  font-weight: 700;
  line-height: 1.3;
  color: var(--color-text);
}

.fallback-sub {
  margin-top: var(--space-sm);
  font-size: 0.9rem;
  color: var(--color-accent);
  font-weight: 600;
}

.hero-content {
  text-align: center;
}

.eyebrow {
  margin: 0 0 var(--space-sm);
  font-size: 0.85rem;
  color: var(--color-teal-light);
  font-weight: 500;
  letter-spacing: 0.05em;
  text-transform: uppercase;
}

.hero h1 {
  margin: 0;
  font-size: clamp(2rem, 6vw, 3rem);
  font-weight: 700;
  line-height: 1.2;
  letter-spacing: -0.03em;
  color: var(--color-heading);
}

.hero-subtitle {
  margin: var(--space-sm) 0 0;
  font-size: clamp(1.1rem, 2.5vw, 1.35rem);
  color: var(--color-text-muted);
}

.hero-meta {
  margin: var(--space-xs) 0 0;
  color: var(--color-text-muted);
  font-size: 0.95rem;
}

.hero-tagline {
  margin: var(--space-md) 0 0;
  font-size: 1.15rem;
  font-weight: 600;
  color: var(--color-accent);
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-sm);
  justify-content: center;
  margin-top: var(--space-lg);
}

@media (min-width: 1024px) {
  .hero-grid {
    grid-template-columns: 1fr 1.1fr;
    gap: var(--space-2xl);
  }

  .hero-visual {
    justify-content: flex-end;
  }

  .book-cover-wrap {
    width: 320px;
  }

  .hero-content {
    text-align: left;
  }

  .hero-actions {
    justify-content: flex-start;
  }
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.75rem 1.5rem;
  font-family: inherit;
  font-size: 0.95rem;
  font-weight: 600;
  border-radius: var(--radius);
  border: 2px solid transparent;
  cursor: pointer;
  transition: background var(--transition), color var(--transition), border-color var(--transition), transform var(--transition);
}

.btn:hover {
  transform: translateY(-1px);
}

.btn-primary {
  background: var(--color-accent);
  color: var(--color-bg);
}

.btn-primary:hover {
  background: var(--color-accent-hover);
  color: var(--color-bg);
}

.btn-secondary {
  background: transparent;
  color: var(--color-text);
  border-color: var(--color-border);
}

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

.btn-lg {
  padding: 1rem 2rem;
  font-size: 1rem;
}

/* Cards */
.card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: var(--space-md);
}

.prose {
  max-width: 52rem;
  margin-inline: auto;
}

.prose p {
  margin: 0 0 var(--space-md);
  color: var(--color-text-muted);
}

.prose p:last-child {
  margin-bottom: 0;
}

.prose strong {
  color: var(--color-text);
}

/* Pipeline */
.pipeline-grid {
  display: grid;
  gap: var(--space-md);
  grid-template-columns: 1fr;
}

@media (min-width: 768px) {
  .pipeline-grid {
    grid-template-columns: repeat(3, 1fr);
  }
}

.pipeline-card {
  text-align: center;
}

.pipeline-step {
  display: inline-block;
  font-size: 2rem;
  font-weight: 700;
  color: var(--color-teal-light);
  line-height: 1;
  margin-bottom: var(--space-sm);
}

.pipeline-card h3 {
  margin: 0 0 var(--space-xs);
  font-size: 1.15rem;
}

.pipeline-card p {
  margin: 0;
  font-size: 0.95rem;
  color: var(--color-text-muted);
}

/* Journey */
.journey-grid {
  display: grid;
  gap: var(--space-md);
  grid-template-columns: 1fr;
}

@media (min-width: 640px) {
  .journey-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (min-width: 1024px) {
  .journey-grid {
    grid-template-columns: repeat(3, 1fr);
  }

  .journey-card:last-child {
    grid-column: span 1;
  }
}

@media (min-width: 1280px) {
  .journey-grid {
    grid-template-columns: repeat(5, 1fr);
  }
}

.part-badge {
  display: inline-block;
  padding: 0.2rem 0.6rem;
  font-size: 0.75rem;
  font-weight: 700;
  background: var(--color-teal);
  color: var(--color-text);
  border-radius: 999px;
  margin-bottom: var(--space-sm);
}

.journey-card h3 {
  margin: 0 0 var(--space-xs);
  font-size: 1.05rem;
}

.journey-card p {
  margin: 0;
  font-size: 0.9rem;
  color: var(--color-text-muted);
}

/* TOC Accordion */
.toc-accordion {
  display: flex;
  flex-direction: column;
  gap: var(--space-sm);
  max-width: 52rem;
  margin-inline: auto;
}

.toc-part {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  overflow: hidden;
}

.toc-part summary {
  padding: var(--space-md);
  font-weight: 600;
  cursor: pointer;
  list-style: none;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-sm);
  transition: background var(--transition);
}

.toc-part summary::-webkit-details-marker {
  display: none;
}

.toc-part summary::after {
  content: "+";
  font-size: 1.25rem;
  font-weight: 400;
  color: var(--color-accent);
  flex-shrink: 0;
}

.toc-part[open] summary::after {
  content: "−";
}

.toc-part summary:hover {
  background: var(--color-surface-alt);
}

.toc-part[open] summary {
  border-bottom: 1px solid var(--color-border);
  background: var(--color-surface-alt);
}

.project-list {
  margin: 0;
  padding: var(--space-md) var(--space-md) var(--space-md) var(--space-lg);
  list-style: decimal;
}

.project-list li {
  padding: var(--space-xs) 0;
  color: var(--color-text-muted);
  font-size: 0.95rem;
}

.project-list li::marker {
  color: var(--color-teal-light);
  font-weight: 600;
}

.toc-note {
  text-align: center;
  margin-top: var(--space-md);
  font-size: 0.9rem;
  color: var(--color-text-muted);
}

/* Audience */
.audience-grid {
  display: grid;
  gap: var(--space-md);
  grid-template-columns: 1fr;
}

@media (min-width: 640px) {
  .audience-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (min-width: 1024px) {
  .audience-grid {
    grid-template-columns: repeat(4, 1fr);
  }
}

.audience-card h3 {
  margin: 0 0 var(--space-xs);
  font-size: 1rem;
  color: var(--color-accent);
}

.audience-card p {
  margin: 0;
  font-size: 0.9rem;
  color: var(--color-text-muted);
}

/* Publisher reviews */
.review-grid {
  display: grid;
  gap: var(--space-md);
  grid-template-columns: 1fr;
}

@media (min-width: 768px) {
  .review-grid {
    grid-template-columns: repeat(3, 1fr);
  }
}

.review-card h3 {
  margin: 0 0 var(--space-sm);
  font-size: 1.1rem;
  color: var(--color-teal-light);
}

.review-card p {
  margin: 0;
  font-size: 0.95rem;
  color: var(--color-text-muted);
}

/* Author message */
.author-message {
  margin: 0;
  padding: var(--space-lg);
  border-left: 4px solid var(--color-accent);
  background: var(--color-surface);
  border-radius: 0 var(--radius) var(--radius) 0;
  max-width: 52rem;
  margin-inline: auto;
}

.author-message p {
  margin: 0 0 var(--space-md);
  color: var(--color-text-muted);
  font-style: italic;
}

.author-message p:last-child {
  margin-bottom: 0;
}

/* Tabs */
.tabs {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-xs);
  justify-content: center;
  margin-bottom: var(--space-lg);
}

.tab-btn {
  padding: 0.6rem 1.2rem;
  font-family: inherit;
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--color-text-muted);
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: 999px;
  cursor: pointer;
  transition: background var(--transition), color var(--transition), border-color var(--transition);
}

.tab-btn:hover {
  color: var(--color-text);
  border-color: var(--color-teal-light);
}

.tab-btn.is-active {
  background: var(--color-teal);
  color: var(--color-text);
  border-color: var(--color-teal);
}

.tab-panel[hidden] {
  display: none;
}

.quote-grid {
  display: grid;
  gap: var(--space-md);
  grid-template-columns: 1fr;
}

@media (min-width: 1024px) {
  .quote-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

.quote-card {
  margin: 0;
  padding: var(--space-md);
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  border-left: 3px solid var(--color-accent);
}

.quote-card p {
  margin: 0 0 var(--space-sm);
  font-size: 0.95rem;
  color: var(--color-text-muted);
}

.quote-card footer {
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--color-teal-light);
}

/* Author */
.author-block {
  max-width: 52rem;
  margin-inline: auto;
}

.author-name {
  font-size: 1.5rem;
  font-weight: 700;
  margin: 0 0 var(--space-md);
  color: var(--color-accent);
}

.author-block p {
  color: var(--color-text-muted);
  margin: 0 0 var(--space-md);
}

.author-books-title {
  margin: var(--space-lg) 0 var(--space-sm);
  font-size: 1rem;
}

.author-books {
  margin: 0;
  padding-left: 1.25rem;
  color: var(--color-text-muted);
}

.author-books li {
  margin-bottom: var(--space-xs);
}

/* CTA */
.cta-section {
  text-align: center;
  background:
    radial-gradient(ellipse 70% 50% at 50% 100%, rgba(26, 107, 122, 0.3), transparent),
    var(--color-bg-alt);
}

.cta-actions {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-sm);
  justify-content: center;
  margin-bottom: var(--space-md);
}

.cta-source {
  margin: 0;
  font-size: 0.85rem;
  color: var(--color-text-muted);
}

/* Footer */
.site-footer {
  padding: var(--space-lg) 0;
  border-top: 1px solid var(--color-border);
  text-align: center;
}

.site-footer p {
  margin: 0;
  font-size: 0.85rem;
  color: var(--color-text-muted);
}

.footer-meta {
  margin-top: var(--space-xs) !important;
  font-size: 0.8rem !important;
  opacity: 0.8;
}