/* ======================================
   Claude Code 소스 딥다이브 — 한국어판
   ====================================== */

@import url('https://fonts.googleapis.com/css2?family=Space+Grotesk:wght@300;400;500;600;700&family=JetBrains+Mono:wght@400;500;600&display=swap');

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

:root {
  --bg-primary:    #1a1816;
  --bg-secondary:  #141211;
  --bg-card:       #22201d;
  --bg-code:       #0d0c0b;
  --text-primary:  #b8b0a4;
  --text-bright:   #e8e0d4;
  --text-dim:      #5c564f;
  --accent-terra:  #c47a50;
  --accent-sage:   #6e9468;
  --accent-slate:  #7d9ab8;
  --accent-gold:   #b8965e;
  --accent-rose:   #c45b54;
  --border-color:  #3a3632;
  --border-light:  #5c564f;
  --radius:        8px;
  --radius-lg:     12px;
}

html { font-size: 16px; scroll-behavior: smooth; }

body {
  font-family: 'Space Grotesk', -apple-system, sans-serif;
  background: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.7;
  min-height: 100vh;
}

a { color: var(--accent-slate); text-decoration: none; transition: color 0.2s; }
a:hover { color: var(--text-bright); }

/* ── Layout ── */
.container { max-width: 900px; margin: 0 auto; padding: 0 24px; }
.container-wide { max-width: 1100px; margin: 0 auto; padding: 0 24px; }

/* ── Hero / Boot Sequence ── */
.hero {
  min-height: 100vh;
  display: grid;
  place-items: center;
  padding: 32px 24px;
  cursor: pointer;
  user-select: none;
  position: relative;
}

.boot-shell {
  width: min(760px, 100%);
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
}

.boot-shell-bar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 16px;
  padding: 12px 20px;
  border-bottom: 1px solid var(--border-color);
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.72rem;
  color: var(--text-dim);
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.boot-terminal {
  font-family: 'JetBrains Mono', monospace;
  font-size: 13px;
  color: var(--text-primary);
  padding: 24px 20px 20px;
  text-align: left;
  width: 100%;
  min-height: 280px;
}

.boot-terminal .line {
  display: block;
  opacity: 0;
  transform: translateY(4px);
  animation: bootIn 0.3s ease forwards;
}

.boot-terminal .ok { color: var(--accent-sage); }
.boot-terminal .warn { color: var(--accent-gold); }
.boot-terminal .path { color: var(--accent-slate); }
.boot-terminal .line:last-child { color: var(--text-bright); }

.boot-footer {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 24px;
  padding: 0 20px 20px;
}

.boot-actions {
  display: flex;
  flex-direction: column;
  align-items: flex-end;
  gap: 8px;
}

.boot-summary {
  font-size: 0.82rem;
  color: var(--text-dim);
}

.hero-enter-link {
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.74rem;
  color: var(--text-bright);
  border-bottom: 1px solid var(--border-light);
}

.hero-enter-link:hover {
  color: var(--accent-terra);
  border-color: var(--accent-terra);
}

@keyframes bootIn {
  to { opacity: 1; transform: translateY(0); }
}

.hero-hint {
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.74rem;
  color: var(--text-dim);
  opacity: 0;
  white-space: nowrap;
  animation: fadeUp 0.6s ease 1.8s forwards;
}

@keyframes fadeUp {
  from { opacity: 0; transform: translateY(10px); }
  to   { opacity: 1; transform: translateY(0); }
}

/* ── Course Hub ── */
.course-hub {
  display: none;
  padding: 0 0 80px;
}

.course-hub.visible { display: block; }

.hub-topbar {
  position: sticky;
  top: 0;
  z-index: 20;
  background: var(--bg-primary);
  border-bottom: 1px solid var(--border-color);
}

.hub-topbar-inner {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 24px;
  padding-top: 16px;
  padding-bottom: 16px;
}

.hub-back-link,
.hub-topbar-meta {
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.74rem;
  letter-spacing: 0.06em;
  text-transform: uppercase;
}

.hub-back-link {
  color: var(--text-primary);
}

.hub-topbar-meta {
  display: flex;
  gap: 16px;
  color: var(--text-dim);
}

.hub-stats {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  border-top: 1px solid var(--border-color);
  border-left: 1px solid var(--border-color);
  align-self: start;
}

.hub-stats div {
  padding: 20px;
  background: var(--bg-secondary);
  border-right: 1px solid var(--border-color);
  border-bottom: 1px solid var(--border-color);
}

.hub-stats dt {
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.72rem;
  color: var(--text-dim);
  letter-spacing: 0.08em;
  text-transform: uppercase;
  margin-bottom: 8px;
}

.hub-stats dd {
  font-size: 1.9rem;
  font-weight: 600;
  color: var(--text-bright);
  line-height: 1.1;
}

.hub-title-block {
  display: grid;
  grid-template-columns: minmax(0, 1.4fr) minmax(320px, 0.9fr);
  gap: 32px;
  align-items: end;
  padding: 48px 0 40px;
}

.hub-title-copy {
  max-width: 680px;
}

.hub-eyebrow {
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.74rem;
  color: var(--accent-terra);
  letter-spacing: 0.08em;
  text-transform: uppercase;
  margin-bottom: 16px;
}

.hub-title-block h1 {
  font-size: 3.2rem;
  font-weight: 700;
  color: var(--text-bright);
  line-height: 1.05;
  letter-spacing: -0.04em;
  margin-bottom: 16px;
}

.hub-description {
  font-size: 1rem;
  color: var(--text-primary);
  max-width: 560px;
}

/* ── Chapter Grid ── */
.chapter-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  border-top: 1px solid var(--border-color);
  border-left: 1px solid var(--border-color);
}

.chapter {
  min-width: 0;
  padding: 24px;
  background: var(--bg-secondary);
  border-right: 1px solid var(--border-color);
  border-bottom: 1px solid var(--border-color);
}

.chapter-header {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  gap: 16px;
  margin-bottom: 12px;
}

.chapter-heading {
  display: flex;
  flex-direction: column;
  gap: 8px;
  min-width: 0;
}

.chapter-num {
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.7rem;
  color: var(--accent-terra);
  text-transform: uppercase;
  letter-spacing: 1px;
  flex-shrink: 0;
}

.ch-architecture .chapter-num { color: var(--accent-terra); }
.ch-tools .chapter-num { color: var(--accent-sage); }
.ch-agents .chapter-num { color: var(--accent-slate); }
.ch-ui .chapter-num { color: var(--accent-gold); }
.ch-infrastructure .chapter-num { color: var(--border-light); }
.ch-connectivity .chapter-num { color: var(--accent-slate); }
.ch-unreleased .chapter-num { color: var(--accent-rose); }
.ch-bigpicture .chapter-num { color: var(--accent-slate); }

.chapter-title {
  font-size: 1.24rem;
  font-weight: 600;
  color: var(--text-bright);
}

.chapter-count {
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.74rem;
  color: var(--text-dim);
  flex-shrink: 0;
  padding-top: 2px;
}

.chapter-meta {
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.74rem;
  color: var(--text-dim);
  letter-spacing: 0.04em;
  text-transform: uppercase;
  padding-bottom: 16px;
  margin-bottom: 8px;
  border-bottom: 1px solid var(--border-color);
}

.lesson-grid {
  display: flex;
  flex-direction: column;
  gap: 0;
}

.lesson-card {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  align-items: center;
  gap: 12px;
  padding: 12px 0;
  background: transparent;
  border: none;
  border-bottom: 1px solid var(--border-color);
  border-radius: 0;
  transition: all 0.15s;
  cursor: pointer;
  text-decoration: none;
  color: var(--text-dim);
}

.lesson-card:hover {
  border-color: var(--border-color);
  background: transparent;
  color: var(--text-bright);
  transform: none;
}

.lesson-card:last-child {
  border-bottom: none;
}

.lesson-copy {
  display: flex;
  flex-direction: column;
  gap: 4px;
  min-width: 0;
}

.lesson-num {
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.7rem;
  color: var(--text-dim);
  letter-spacing: 0.08em;
}

.lesson-name {
  font-size: 0.95rem;
  font-weight: 500;
  color: inherit;
}

.lesson-arrow {
  margin-left: auto;
  color: var(--text-dim);
  font-size: 1rem;
  transition: transform 0.2s;
}

.lesson-card:hover .lesson-num {
  color: var(--accent-slate);
}

.lesson-card:hover .lesson-arrow {
  transform: translateX(4px);
  color: var(--accent-terra);
}

/* ── Lesson Page ── */
.lesson-page { padding: 40px 0 80px; }

.breadcrumb {
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.75rem;
  color: var(--text-dim);
  margin-bottom: 40px;
}

.breadcrumb a { color: var(--accent-slate); }
.breadcrumb .sep { margin: 0 6px; color: var(--border-light); }

.lesson-hero {
  margin-bottom: 48px;
}

.lesson-hero h1 {
  font-size: 2rem;
  font-weight: 700;
  color: var(--text-bright);
  margin-bottom: 12px;
  line-height: 1.3;
}

.lesson-hero .subtitle {
  font-size: 1.05rem;
  color: var(--text-dim);
  font-style: italic;
  max-width: 680px;
}

/* ── Sections ── */
.section {
  margin-bottom: 48px;
}

.section-header {
  display: flex;
  align-items: baseline;
  gap: 12px;
  margin-bottom: 20px;
}

.section-num {
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.8rem;
  color: var(--accent-terra);
  flex-shrink: 0;
}

.section h2 {
  font-size: 1.4rem;
  font-weight: 600;
  color: var(--text-bright);
}

.section h3 {
  font-size: 1.15rem;
  font-weight: 600;
  color: var(--text-bright);
  margin: 28px 0 12px;
}

.section h4 {
  font-size: 1rem;
  font-weight: 600;
  color: var(--accent-gold);
  margin: 24px 0 10px;
}

.section p {
  margin-bottom: 14px;
}

.section ul, .section ol {
  margin: 12px 0 16px 20px;
}

.section li {
  margin-bottom: 6px;
}

/* ── Code Blocks ── */
pre {
  background: var(--bg-code);
  border: 1px solid var(--border-color);
  border-radius: var(--radius);
  padding: 16px 20px;
  overflow-x: auto;
  margin: 16px 0;
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.82rem;
  line-height: 1.6;
  color: var(--text-primary);
}

code {
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.85em;
  background: var(--bg-code);
  padding: 2px 6px;
  border-radius: 4px;
  color: var(--accent-gold);
}

pre code {
  background: none;
  padding: 0;
  color: inherit;
}

.code-comment { color: var(--text-dim); }
.code-keyword { color: var(--accent-slate); }
.code-string { color: var(--accent-sage); }
.code-func { color: var(--accent-gold); }

/* ── Deep Dive Callout ── */
.deep-dive {
  border-left: 3px solid var(--accent-terra);
  background: rgba(196, 122, 80, 0.06);
  padding: 20px 24px;
  margin: 24px 0;
  border-radius: 0 var(--radius) var(--radius) 0;
}

.deep-dive-title {
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--accent-terra);
  text-transform: uppercase;
  letter-spacing: 0.5px;
  margin-bottom: 10px;
}

/* ── Gotcha / Warning ── */
.gotcha {
  border-left: 3px solid var(--accent-gold);
  background: rgba(212, 168, 87, 0.06);
  padding: 20px 24px;
  margin: 24px 0;
  border-radius: 0 var(--radius) var(--radius) 0;
}

.gotcha-title {
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--accent-gold);
  text-transform: uppercase;
  letter-spacing: 0.5px;
  margin-bottom: 10px;
}

/* ── Source Files Reference ── */
.source-files {
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.78rem;
  color: var(--text-dim);
  padding: 12px 16px;
  background: var(--bg-card);
  border-radius: var(--radius);
  margin-bottom: 24px;
}

.source-files strong { color: var(--accent-slate); }

/* ── Mermaid Diagrams ── */
.mermaid {
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius);
  padding: 24px;
  margin: 20px 0;
  overflow-x: auto;
  text-align: center;
}

/* ── Quiz ── */
.quiz {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 32px;
  margin: 48px 0;
}

.quiz-title {
  font-size: 1.2rem;
  font-weight: 600;
  color: var(--text-bright);
  margin-bottom: 24px;
}

.quiz-question {
  margin-bottom: 28px;
  padding-bottom: 24px;
  border-bottom: 1px solid var(--border-color);
}

.quiz-question:last-of-type { border-bottom: none; }

.quiz-q {
  font-weight: 600;
  color: var(--text-bright);
  margin-bottom: 12px;
}

.quiz-options {
  list-style: none;
  margin: 0;
  padding: 0;
}

.quiz-options li {
  padding: 10px 14px;
  margin: 4px 0;
  border: 1px solid var(--border-color);
  border-radius: var(--radius);
  cursor: pointer;
  transition: all 0.2s;
  font-size: 0.9rem;
}

.quiz-options li:hover {
  border-color: var(--accent-slate);
  background: rgba(125, 154, 184, 0.08);
}

.quiz-options li.correct {
  border-color: var(--accent-sage);
  background: rgba(110, 148, 104, 0.12);
  color: var(--accent-sage);
}

.quiz-options li.wrong {
  border-color: var(--accent-rose);
  background: rgba(184, 110, 110, 0.12);
  color: var(--accent-rose);
}

.quiz-options li.disabled {
  pointer-events: none;
  opacity: 0.6;
}

.quiz-feedback {
  margin-top: 10px;
  font-size: 0.85rem;
  color: var(--text-dim);
  display: none;
  padding: 10px 14px;
  background: var(--bg-secondary);
  border-radius: var(--radius);
}

.quiz-feedback.visible { display: block; }

.quiz-score {
  text-align: center;
  font-family: 'JetBrains Mono', monospace;
  font-size: 1.4rem;
  color: var(--accent-terra);
  margin-top: 20px;
}

/* ── Navigation ── */
.lesson-nav {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding-top: 40px;
  margin-top: 48px;
  border-top: 1px solid var(--border-color);
}

.nav-link {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 12px 20px;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius);
  color: var(--text-primary);
  font-size: 0.9rem;
  transition: all 0.2s;
}

.nav-link:hover {
  border-color: var(--accent-terra);
  color: var(--text-bright);
}

.nav-link.prev .arrow { margin-right: 4px; }
.nav-link.next .arrow { margin-left: 4px; }

/* ── Key Takeaways ── */
.takeaways {
  background: rgba(110, 148, 104, 0.06);
  border: 1px solid rgba(110, 148, 104, 0.2);
  border-radius: var(--radius-lg);
  padding: 24px 28px;
  margin: 32px 0;
}

.takeaways h3 {
  color: var(--accent-sage);
  margin-bottom: 14px;
  font-size: 1rem;
}

.takeaways ul {
  margin-left: 16px;
}

.takeaways li {
  margin-bottom: 8px;
  color: var(--text-primary);
}

/* ── Responsive ── */
@media (max-width: 768px) {
  .boot-shell-bar,
  .boot-footer,
  .hub-topbar-inner,
  .hub-topbar-meta {
    flex-direction: column;
    align-items: flex-start;
  }

  .hub-title-block,
  .chapter-grid,
  .hub-stats {
    grid-template-columns: 1fr;
  }

  .hub-title-block {
    align-items: flex-start;
  }

  .hub-title-block h1 { font-size: 2.4rem; }
  .lesson-hero h1 { font-size: 1.6rem; }
  .lesson-nav { flex-direction: column; gap: 12px; }
  .quiz { padding: 20px; }
  .container { padding: 0 16px; }
}

@media (max-width: 480px) {
  .hero { padding: 24px 16px; }
  .boot-terminal { font-size: 11px; min-height: 240px; }
  .boot-shell-bar,
  .boot-terminal,
  .boot-footer,
  .hub-stats div,
  .chapter {
    padding-left: 16px;
    padding-right: 16px;
  }

  .hub-title-block {
    padding-top: 32px;
    gap: 24px;
  }

  .hub-title-block h1 { font-size: 1.8rem; }
  .boot-terminal { font-size: 11px; }
}