:root {
  --bg: #0b1020;
  --panel: rgba(17, 24, 39, 0.82);
  --panel-2: rgba(30, 41, 59, 0.72);
  --line: rgba(148, 163, 184, 0.18);
  --text: #e5eefb;
  --muted: #95a6c6;
  --accent: #6ee7f9;
  --accent-2: #8b5cf6;
  --good: #22c55e;
  --bad: #ef4444;
  --shadow: 0 20px 50px rgba(0, 0, 0, 0.28);
  --radius: 22px;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  background:
    radial-gradient(circle at top left, rgba(110, 231, 249, 0.14), transparent 28%),
    radial-gradient(circle at top right, rgba(139, 92, 246, 0.15), transparent 24%),
    linear-gradient(180deg, #09111f, #11182a 44%, #0f172a);
  color: var(--text);
  min-height: 100vh;
}

a { color: inherit; }
button, input { font: inherit; }
img { max-width: 100%; }
mark {
  background: rgba(250, 204, 21, 0.3);
  color: #fff8c5;
  padding: 0 2px;
  border-radius: 4px;
}

.app-shell {
  display: grid;
  grid-template-columns: 320px 1fr;
  min-height: 100vh;
}

.sidebar {
  position: sticky;
  top: 0;
  height: 100vh;
  padding: 24px 18px;
  border-right: 1px solid var(--line);
  background: rgba(5, 10, 20, 0.72);
  backdrop-filter: blur(16px);
  overflow: auto;
}

.brand {
  display: flex;
  gap: 14px;
  align-items: center;
  margin-bottom: 20px;
}
.brand h1 { margin: 0; font-size: 1.25rem; }
.brand p { margin: 4px 0 0; color: var(--muted); font-size: 0.92rem; }
.brand-badge {
  width: 50px;
  height: 50px;
  border-radius: 16px;
  display: grid;
  place-items: center;
  font-weight: 800;
  background: linear-gradient(135deg, var(--accent), var(--accent-2));
  color: #07111f;
  box-shadow: var(--shadow);
}

.progress-card,
.module-link,
.hero,
.toolbar,
.lesson-card,
.inline-quiz-card,
.quiz-card,
.glossary-card,
.metric-card,
.score-banner,
.flow-guide-card {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}

.progress-card { padding: 16px; margin-bottom: 18px; }
.label-row { display: flex; justify-content: space-between; gap: 12px; }
.progress-bar {
  margin-top: 10px;
  height: 10px;
  border-radius: 999px;
  background: rgba(148, 163, 184, 0.18);
  overflow: hidden;
}
.progress-bar > div {
  height: 100%;
  width: 0;
  background: linear-gradient(90deg, var(--accent), var(--accent-2));
}
.muted { color: var(--muted); }
.status-card strong { color: #fef3c7; }

.module-nav { display: grid; gap: 10px; }
.module-link {
  display: block;
  padding: 14px;
  text-decoration: none;
  transition: transform .15s ease, border-color .15s ease, background .15s ease;
}
.module-link:hover,
.module-link.active {
  transform: translateY(-1px);
  border-color: rgba(110, 231, 249, 0.35);
  background: rgba(17, 24, 39, 0.98);
}
.module-link strong { display: block; margin-bottom: 6px; }
.module-link span { color: var(--muted); font-size: 0.92rem; }
.sidebar-footer { margin-top: 18px; }

.main { padding: 14px; min-width: 0; max-width: 720px; margin: 0 auto; }
.hero {
  display: flex;
  justify-content: space-between;
  gap: 20px;
  padding: 26px;
  align-items: flex-end;
}
.eyebrow {
  display: inline-block;
  margin-bottom: 8px;
  padding: 6px 10px;
  border-radius: 999px;
  color: #d6f7ff;
  background: rgba(110, 231, 249, 0.14);
  font-size: 0.82rem;
  letter-spacing: .04em;
  text-transform: uppercase;
}
.hero h2 { margin: 0; font-size: clamp(1.7rem, 3vw, 2.8rem); line-height: 1.05; }
.hero-copy { max-width: 760px; color: var(--muted); font-size: 1rem; }
.hero-actions { display: flex; flex-wrap: wrap; gap: 10px; }

.primary-btn,
.secondary-btn,
.ghost-btn,
.tab,
.choice-btn,
.reveal-btn {
  border: 0;
  border-radius: 14px;
  padding: 12px 16px;
  cursor: pointer;
  transition: transform .15s ease, opacity .15s ease, background .15s ease;
}
.primary-btn:hover,
.secondary-btn:hover,
.ghost-btn:hover,
.tab:hover,
.choice-btn:hover,
.reveal-btn:hover { transform: translateY(-1px); }
.primary-btn {
  background: linear-gradient(135deg, var(--accent), var(--accent-2));
  color: #07111f;
  font-weight: 700;
}
.secondary-btn {
  background: rgba(148, 163, 184, 0.14);
  color: var(--text);
}
.ghost-btn {
  width: 100%;
  background: transparent;
  border: 1px solid var(--line);
  color: var(--muted);
}

.toolbar {
  margin-top: 18px;
  padding: 16px;
  display: flex;
  justify-content: space-between;
  gap: 16px;
  align-items: center;
  flex-wrap: wrap;
}
.tabs { display: flex; gap: 8px; flex-wrap: wrap; }
.tab {
  background: rgba(148, 163, 184, 0.08);
  color: var(--muted);
}
.tab.active {
  background: rgba(110, 231, 249, 0.16);
  color: var(--text);
}
.search-wrap {
  display: grid;
  gap: 6px;
  min-width: 280px;
  color: var(--muted);
}
.search-wrap input {
  border: 1px solid var(--line);
  background: rgba(15, 23, 42, 0.7);
  color: var(--text);
  border-radius: 14px;
  padding: 12px 14px;
}

#content { margin-top: 22px; display: grid; gap: 18px; }

.home-layout,
.study-layout,
.quiz-layout,
.glossary-layout {
  display: grid;
  gap: 18px;
  min-width: 0;
}

.home-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 16px;
}

.home-card {
  padding: 18px;
  background: rgba(15, 23, 42, 0.65);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}

.home-card-wide {
  grid-column: span 2;
}

.home-card h3 {
  margin: 0 0 8px;
}

.home-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 14px;
}

.lesson-card,
.inline-quiz-card,
.quiz-card,
.glossary-card,
.flow-guide-card {
  padding: 18px;
  min-width: 0;
  overflow: hidden;
}

.flow-guide-card h3 {
  margin: 6px 0 8px;
  font-size: 1.2rem;
}

.flow-guide-eyebrow {
  display: inline-flex;
  padding: 5px 10px;
  border-radius: 999px;
  background: rgba(110, 231, 249, 0.14);
  color: #d6f7ff;
  font-size: 0.78rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.lesson-hero {
  display: flex;
  justify-content: space-between;
  gap: 16px;
  align-items: start;
  margin-bottom: 18px;
}
.lesson-tag {
  display: inline-flex;
  padding: 5px 10px;
  border-radius: 999px;
  background: rgba(139, 92, 246, 0.16);
  color: #e9ddff;
  font-size: 0.8rem;
  margin-bottom: 10px;
}
.lesson-hero h3 { margin: 0 0 8px; font-size: clamp(1.5rem, 2.5vw, 2.2rem); }
.lesson-meta {
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
}
.mini-metric {
  min-width: 94px;
  padding: 12px 14px;
  border-radius: 18px;
  background: rgba(15, 23, 42, 0.72);
  border: 1px solid var(--line);
  text-align: center;
}
.mini-metric strong { display: block; font-size: 1.3rem; }
.mini-metric span { color: var(--muted); font-size: 0.85rem; }

.takeaway-strip {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: 18px;
}
.chip {
  border-radius: 999px;
  padding: 7px 11px;
  background: rgba(148, 163, 184, 0.12);
  color: var(--muted);
  font-size: 0.84rem;
}

.lesson-html {
  background: rgba(8, 13, 25, 0.6);
  border: 1px solid var(--line);
  border-radius: 20px;
  padding: 10px;
  overflow: hidden;
}
.prose {
  line-height: 1.72;
  font-size: 1rem;
}
.prose h1,
.prose h2,
.prose h3,
.prose h4 {
  line-height: 1.2;
  margin-top: 1.5em;
  margin-bottom: 0.6em;
}
.prose h1:first-child,
.prose h2:first-child,
.prose h3:first-child { margin-top: 0; }
.prose p,
.prose li { color: #dbe7fb; }
.prose ul,
.prose ol { padding-left: 1.25rem; }
.prose code {
  background: rgba(148, 163, 184, 0.12);
  padding: 0.12rem 0.35rem;
  border-radius: 6px;
  font-size: 0.92em;
}
.prose pre {
  background: rgba(2, 6, 23, 0.8);
  padding: 14px;
  border-radius: 16px;
  overflow: auto;
}
.prose blockquote {
  margin: 1rem 0;
  padding: 0.2rem 0 0.2rem 1rem;
  border-left: 3px solid rgba(110, 231, 249, 0.5);
  color: #cfe4ff;
}
.table-scroll {
  width: 100%;
  overflow-x: auto;
  overflow-y: hidden;
  -webkit-overflow-scrolling: touch;
}
.prose table {
  border-collapse: collapse;
  table-layout: auto;
  display: table;
  font-size: 0.84rem;
  line-height: 1.35;
  margin: 0;
}
.prose th,
.prose td {
  border: 1px solid var(--line);
  padding: 6px 7px;
  white-space: normal;
  overflow-wrap: break-word;
  min-width: 6em;
  max-width: 40ch;
}

.section-head {
  display: flex;
  justify-content: space-between;
  gap: 14px;
  align-items: center;
  margin-bottom: 14px;
  flex-wrap: wrap;
}

.quiz-summary-row {
  display: flex;
  justify-content: space-between;
  gap: 12px;
  margin-bottom: 14px;
  flex-wrap: wrap;
}
.quiz-stack { display: grid; gap: 12px; }
.quiz-question {
  padding: 16px;
  border-radius: 18px;
  background: rgba(15, 23, 42, 0.6);
  border: 1px solid var(--line);
}
.question-top {
  display: flex;
  justify-content: space-between;
  gap: 10px;
  align-items: start;
}
.question-number {
  color: var(--accent);
  font-size: .82rem;
  text-transform: uppercase;
  letter-spacing: .06em;
  margin-bottom: 8px;
}
.choice-list {
  display: grid;
  gap: 10px;
  margin-top: 14px;
}
.choice-btn {
  text-align: left;
  background: rgba(148, 163, 184, 0.08);
  color: var(--text);
  border: 1px solid transparent;
}
.choice-btn.selected {
  border-color: rgba(110, 231, 249, 0.5);
  background: rgba(110, 231, 249, 0.12);
}
.choice-btn.correct {
  background: rgba(34, 197, 94, 0.14);
  border-color: rgba(34, 197, 94, 0.45);
}
.choice-btn.incorrect {
  background: rgba(239, 68, 68, 0.14);
  border-color: rgba(239, 68, 68, 0.42);
}
.answer-box {
  display: none;
  margin-top: 12px;
  padding: 14px;
  border-radius: 16px;
  background: rgba(2, 6, 23, 0.55);
  border: 1px solid var(--line);
  color: #d8e7ff;
}
.answer-box.visible { display: block; }
.reveal-btn {
  margin-top: 12px;
  background: rgba(139, 92, 246, 0.16);
  color: #efe8ff;
}
.score-banner {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 14px;
  align-items: center;
  padding: 18px;
  background: linear-gradient(135deg, rgba(110, 231, 249, 0.12), rgba(139, 92, 246, 0.12));
}
.score-banner.submitted {
  background: linear-gradient(135deg, rgba(52, 211, 153, 0.16), rgba(16, 185, 129, 0.14));
  border-color: rgba(52, 211, 153, 0.28);
}

.submit-row {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 16px;
  align-items: center;
}
.submit-btn {
  background: linear-gradient(135deg, #34d399, #10b981);
  color: #062b1f;
  font-weight: 800;
}
.submit-btn:disabled,
.choice-btn:disabled,
.reveal-btn:disabled {
  opacity: 0.65;
  cursor: not-allowed;
  transform: none;
}
.lock-note,
.bank-note {
  color: #c7d2fe;
  font-size: 0.92rem;
}

.glossary-list {
  display: flex;
  flex-direction: column;
}
.glossary-row {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: 8px 16px;
  padding: 10px 0;
  border-bottom: 1px solid var(--line);
}
.glossary-term {
  display: flex;
  flex-direction: column;
  gap: 2px;
}
.glossary-term .fr { color: #c4b5fd; font-weight: 700; }
.glossary-term .en { color: #e2e8f0; }
.glossary-term .ko { color: #fef3c7; font-size: 0.9rem; }
.glossary-note { color: var(--muted); font-size: 0.88rem; line-height: 1.45; }

@media (max-width: 1100px) {
  .app-shell { grid-template-columns: 1fr; }
  .sidebar {
    position: static;
    height: auto;
    border-right: 0;
    border-bottom: 1px solid var(--line);
  }
}

@media (max-width: 720px) {
  .main { padding: 0; }
  .hero,
  .toolbar,
  .inline-quiz-card,
  .quiz-card,
  .glossary-card,
  .flow-guide-card,
  .home-card { padding: 12px; }
  .home-card-wide {
    grid-column: span 1;
  }
  .lesson-card {
    padding: 12px 0 0;
    border-left: 0;
    border-right: 0;
    border-radius: 0;
  }
  .lesson-hero,
  .takeaway-strip {
    padding-inline: 12px;
  }
  .hero { align-items: start; }
  .hero-actions,
  .lesson-meta,
  .section-head,
  .quiz-summary-row { width: 100%; }
  .search-wrap { min-width: 100%; }
  .lesson-html {
    padding: 0;
    border-left: 0;
    border-right: 0;
    border-radius: 0;
  }
  .prose { font-size: 0.97rem; }
  .primary-btn,
  .secondary-btn,
  .tab,
  .choice-btn,
  .reveal-btn { width: 100%; }
  .tabs { width: 100%; }
  .tab { text-align: center; }
}