/* ============================================
   MODULE PAGE STYLES
   ============================================ */

.progress-bar {
  position: sticky;
  top: 64px;
  height: 3px;
  background: rgba(0,0,0,0.05);
  z-index: 99;
}

.progress-fill {
  height: 100%;
  background: var(--oil);
  width: 0%;
  transition: width 0.2s;
}

/* ----- Module Hero ----- */
.module-hero {
  background: linear-gradient(135deg, var(--paper) 0%, var(--bone) 100%);
  padding: 4rem 2rem 5rem;
  border-bottom: var(--border);
  position: relative;
  overflow: hidden;
}

.module-hero::before {
  content: '01';
  position: absolute;
  top: -50px;
  right: -30px;
  font-family: var(--font-display);
  font-size: 20rem;
  font-weight: 900;
  color: var(--oil);
  opacity: 0.08;
  line-height: 1;
  pointer-events: none;
}

.module-hero-inner {
  max-width: 900px;
  margin: 0 auto;
  position: relative;
  z-index: 1;
}

.module-breadcrumb {
  display: flex;
  gap: 0.6rem;
  font-family: var(--font-mono);
  font-size: 0.85rem;
  color: var(--concrete);
  margin-bottom: 1.5rem;
}

.module-breadcrumb a:hover { color: var(--oil); }

.module-title {
  font-family: var(--font-display);
  font-size: clamp(2.5rem, 5vw, 4rem);
  font-weight: 900;
  line-height: 1;
  letter-spacing: -0.02em;
  margin-bottom: 1.5rem;
}

.module-lead {
  font-size: 1.3rem;
  color: var(--steel);
  max-width: 700px;
  margin-bottom: 2.5rem;
}

.module-info {
  display: flex;
  gap: 2rem;
  flex-wrap: wrap;
  font-family: var(--font-mono);
  font-size: 0.9rem;
  color: var(--steel);
}

.info-item b {
  color: var(--oil);
  font-size: 1.1rem;
  margin-right: 0.3rem;
}

/* ----- Module Content Layout ----- */
.module-content {
  max-width: 1200px;
  margin: 0 auto;
  padding: 4rem 2rem;
  display: grid;
  grid-template-columns: 240px 1fr;
  gap: 4rem;
  align-items: start;
}

.module-toc {
  position: sticky;
  top: 100px;
  padding: 1.5rem;
  background: var(--bone);
  border-radius: var(--radius);
  border-left: 3px solid var(--oil);
}

.module-toc h4 {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  color: var(--concrete);
  margin-bottom: 1rem;
}

.module-toc ol {
  list-style: none;
  counter-reset: toc;
}

.module-toc li {
  counter-increment: toc;
  padding: 0.5rem 0;
  font-size: 0.9rem;
  border-bottom: 1px dashed rgba(0,0,0,0.1);
}

.module-toc li:last-child { border: none; }

.module-toc li::before {
  content: counter(toc, decimal-leading-zero) " ";
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--concrete);
  margin-right: 0.5rem;
}

.module-toc a:hover { color: var(--oil); }
.module-toc a.active { color: var(--oil); font-weight: 700; }

/* ----- Lessons ----- */
.lesson {
  margin-bottom: 5rem;
  scroll-margin-top: 100px;
}

.lesson-num {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  color: var(--oil);
  margin-bottom: 0.8rem;
  font-weight: 700;
}

.lesson h2 {
  font-family: var(--font-display);
  font-size: 2.5rem;
  font-weight: 900;
  line-height: 1;
  letter-spacing: -0.02em;
  margin-bottom: 1.5rem;
}

.lesson h3 {
  font-family: var(--font-display);
  font-size: 1.5rem;
  font-weight: 700;
  margin: 2.5rem 0 1rem;
}

.lesson h4 {
  font-family: var(--font-mono);
  font-size: 0.9rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  margin-bottom: 1rem;
  color: var(--oil-dark);
}

.lesson p { margin-bottom: 1.2rem; line-height: 1.7; font-size: 1.05rem; color: var(--graphite); }

.lesson-intro {
  font-size: 1.2rem !important;
  color: var(--ink) !important;
  border-left: 3px solid var(--oil);
  padding-left: 1.2rem;
  margin-bottom: 2rem !important;
}

.lesson strong { color: var(--ink); font-weight: 700; }

/* ----- Timeline ----- */
.timeline {
  display: flex;
  flex-direction: column;
  gap: 0;
  margin: 2rem 0;
  position: relative;
}

.timeline::before {
  content: '';
  position: absolute;
  left: 80px;
  top: 10px;
  bottom: 10px;
  width: 2px;
  background: var(--concrete);
}

.timeline-item {
  display: grid;
  grid-template-columns: 100px 1fr;
  gap: 2rem;
  padding: 1rem 0;
  position: relative;
}

.timeline-item::before {
  content: '';
  position: absolute;
  left: 74px;
  top: 1.5rem;
  width: 14px;
  height: 14px;
  border-radius: 50%;
  background: var(--paper);
  border: 3px solid var(--ink);
}

.timeline-item.highlight::before {
  background: var(--oil);
  border-color: var(--oil);
  box-shadow: 0 0 0 6px rgba(255, 140, 26, 0.2);
}

.timeline-year {
  font-family: var(--font-mono);
  font-size: 0.85rem;
  font-weight: 700;
  color: var(--concrete);
  text-align: right;
  padding-right: 1rem;
  align-self: start;
  padding-top: 1.4rem;
}

.timeline-item.highlight .timeline-year { color: var(--oil); }
.timeline-item p { margin: 0; padding: 1rem 1.5rem; background: var(--bone); border-radius: var(--radius); }
.timeline-item.highlight p { background: rgba(255, 140, 26, 0.08); border-left: 3px solid var(--oil); }

/* ----- Callouts ----- */
.callout {
  margin: 2rem 0;
  padding: 1.5rem 1.8rem;
  border-radius: var(--radius);
  font-size: 1rem;
  line-height: 1.6;
}

.callout b { display: block; margin-bottom: 0.5rem; font-family: var(--font-mono); font-size: 0.85rem; }
.callout-info { background: #e8f4f8; border-left: 4px solid var(--steam); }
.callout-warning { background: #fff5e6; border-left: 4px solid var(--oil); }
.callout-danger { background: #fce8e6; border-left: 4px solid var(--warning); }

/* ----- Card Grid ----- */
.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 1.5rem;
  margin: 1.5rem 0 2rem;
}

.info-card {
  background: var(--white);
  border: var(--border);
  border-radius: var(--radius);
  padding: 1.5rem;
  transition: all 0.3s;
}

.info-card:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
  border-color: var(--oil);
}

.info-card-icon {
  font-size: 2rem;
  margin-bottom: 0.8rem;
}

.info-card h4 {
  font-family: var(--font-display);
  font-size: 1.2rem;
  text-transform: none;
  letter-spacing: 0;
  color: var(--ink);
  margin-bottom: 0.5rem;
}

.info-card p { font-size: 0.95rem !important; margin: 0; }

/* ----- Formula Box ----- */
.formula-box {
  background: var(--ink);
  color: var(--paper);
  padding: 2rem;
  border-radius: var(--radius);
  margin: 2rem 0;
  border-left: 4px solid var(--oil);
}

.formula-box h4 { color: var(--oil); }

.formula {
  font-family: var(--font-mono);
  font-size: 1.8rem;
  text-align: center;
  padding: 1.5rem 0;
  letter-spacing: 0.02em;
}

.formula-symbol { color: var(--oil-light); font-weight: 700; }
.formula-eq { margin: 0 0.8rem; color: var(--bone); }
.formula-unit { font-size: 1rem; color: var(--concrete); margin-left: 0.5rem; }

.formula-legend {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  gap: 0.5rem;
  font-family: var(--font-mono);
  font-size: 0.85rem;
  margin-top: 1rem;
  padding-top: 1rem;
  border-top: 1px dashed rgba(244, 241, 234, 0.2);
}

.formula-legend b { color: var(--oil-light); }
.formula-explain { font-size: 1rem !important; color: var(--bone) !important; margin: 1rem 0 0 !important; }

/* ----- Big Quote ----- */
.big-quote {
  font-family: var(--font-display);
  font-size: 1.6rem;
  font-style: italic;
  line-height: 1.4;
  padding: 2.5rem 3rem;
  background: var(--bone);
  border-radius: var(--radius);
  border-left: 6px solid var(--oil);
  margin: 2rem 0;
  position: relative;
}

.big-quote::before {
  content: '"';
  position: absolute;
  top: -10px;
  left: 20px;
  font-size: 6rem;
  color: var(--oil);
  font-family: var(--font-display);
  opacity: 0.3;
}

.big-quote cite {
  display: block;
  margin-top: 1rem;
  font-size: 0.9rem;
  font-style: normal;
  font-family: var(--font-mono);
  color: var(--concrete);
}

/* ----- Interactive Demo ----- */
.interactive-demo {
  background: var(--white);
  border: 2px solid var(--ink);
  border-radius: var(--radius);
  padding: 2rem;
  margin: 2rem 0;
}

.interactive-demo h4 {
  font-family: var(--font-display);
  font-size: 1.3rem;
  text-transform: none;
  letter-spacing: 0;
  color: var(--ink);
}

.demo-instructions { font-size: 0.95rem; color: var(--steel); margin-bottom: 1.5rem; }

.pascal-svg {
  width: 100%;
  height: auto;
  max-height: 400px;
  display: block;
  margin: 1rem auto;
  background: var(--paper);
  border-radius: var(--radius);
}

.demo-controls {
  background: var(--bone);
  padding: 1.5rem;
  border-radius: var(--radius);
  margin: 1.5rem 0 1rem;
}

.demo-controls label {
  display: block;
  font-family: var(--font-mono);
  font-size: 0.9rem;
  margin-bottom: 0.5rem;
}

.demo-controls input[type=range] {
  width: 100%;
  margin-top: 0.8rem;
  accent-color: var(--oil);
}

.demo-result {
  background: rgba(255, 140, 26, 0.1);
  padding: 1rem 1.5rem;
  border-radius: var(--radius);
  font-size: 0.95rem;
  border-left: 3px solid var(--oil);
}

.demo-result strong { color: var(--oil-dark); }

/* ----- Calculator ----- */
.calculator {
  background: var(--ink);
  color: var(--paper);
  border-radius: var(--radius);
  padding: 2rem;
  margin: 2rem 0;
}

.calculator h4 { color: var(--oil-light); font-family: var(--font-display); font-size: 1.3rem; text-transform: none; letter-spacing: 0; }

.calc-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 1rem;
  margin: 1.5rem 0;
}

.calc-grid label {
  display: block;
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: rgba(244, 241, 234, 0.7);
  margin-bottom: 0.3rem;
}

.calc-grid input {
  display: block;
  width: 100%;
  padding: 0.7rem;
  margin-top: 0.4rem;
  background: var(--graphite);
  color: var(--paper);
  border: 1px solid var(--steel);
  border-radius: var(--radius);
  font-family: var(--font-mono);
  font-size: 1.1rem;
}

.calc-grid input:focus {
  outline: none;
  border-color: var(--oil);
  box-shadow: 0 0 0 3px rgba(255, 140, 26, 0.3);
}

.calc-result {
  margin-top: 1.5rem;
  padding: 1.5rem;
  background: rgba(255, 140, 26, 0.1);
  border-radius: var(--radius);
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 1rem;
}

.result-item {
  font-family: var(--font-mono);
  font-size: 0.85rem;
}

.result-item span { display: block; color: rgba(244, 241, 234, 0.6); margin-bottom: 0.3rem; }
.result-item strong { font-size: 1.4rem; color: var(--oil-light); }

/* ----- Comparison ----- */
.comparison {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1.5rem;
  margin: 2rem 0;
}

.comparison-item {
  padding: 1.5rem;
  border-radius: var(--radius);
  background: var(--white);
  border: 2px solid;
}

.comparison-item.good { border-color: #7fc97f; }
.comparison-item.bad { border-color: var(--warning); }

.comparison-item h4 {
  font-family: var(--font-display);
  font-size: 1.3rem;
  text-transform: none;
  letter-spacing: 0;
  margin-bottom: 1rem;
}

.flow-viz {
  height: 80px;
  background: linear-gradient(90deg, transparent, var(--bone), transparent);
  border-radius: var(--radius);
  position: relative;
  overflow: hidden;
  margin: 1rem 0;
  display: flex;
  align-items: center;
  justify-content: space-around;
}

.flow-viz.laminar .flow-line {
  width: 100%;
  height: 4px;
  background: var(--steam);
  position: absolute;
  animation: laminarFlow 2s linear infinite;
}

.flow-viz.laminar .flow-line:nth-child(1) { top: 18px; animation-delay: 0s; }
.flow-viz.laminar .flow-line:nth-child(2) { top: 30px; animation-delay: 0.4s; }
.flow-viz.laminar .flow-line:nth-child(3) { top: 42px; animation-delay: 0.2s; }
.flow-viz.laminar .flow-line:nth-child(4) { top: 54px; animation-delay: 0.6s; }
.flow-viz.laminar .flow-line:nth-child(5) { top: 66px; animation-delay: 0.3s; }

@keyframes laminarFlow {
  0% { transform: translateX(-100%); opacity: 0; }
  20%, 80% { opacity: 1; }
  100% { transform: translateX(100%); opacity: 0; }
}

.flow-viz.turbulent .flow-swirl {
  width: 30px;
  height: 30px;
  border: 3px solid var(--warning);
  border-radius: 50%;
  border-top-color: transparent;
  animation: turbulentSwirl 1s linear infinite;
}

.flow-viz.turbulent .flow-swirl:nth-child(2) { animation-delay: 0.3s; }
.flow-viz.turbulent .flow-swirl:nth-child(3) { animation-delay: 0.6s; }

@keyframes turbulentSwirl {
  to { transform: rotate(360deg); }
}

/* ----- Data Table ----- */
.data-table {
  width: 100%;
  border-collapse: collapse;
  margin: 1.5rem 0;
  font-family: var(--font-mono);
  font-size: 0.95rem;
}

.data-table th {
  background: var(--ink);
  color: var(--paper);
  padding: 0.8rem 1rem;
  text-align: left;
  font-size: 0.8rem;
  letter-spacing: 0.05em;
  text-transform: uppercase;
}

.data-table td {
  padding: 0.8rem 1rem;
  border-bottom: 1px solid var(--concrete);
  background: var(--white);
}

.data-table tr:hover td { background: var(--bone); }

/* ----- Quiz ----- */
.quiz-section { background: var(--bone); padding: 3rem 2rem; border-radius: var(--radius); margin-top: 5rem; }

.quiz-question {
  background: var(--white);
  padding: 1.5rem;
  border-radius: var(--radius);
  margin-bottom: 1rem;
  border-left: 4px solid var(--concrete);
  transition: border-color 0.3s;
}

.quiz-question.correct { border-color: #7fc97f; }
.quiz-question.incorrect { border-color: var(--warning); }

.quiz-question h4 {
  font-family: var(--font-display);
  font-size: 1.1rem;
  text-transform: none;
  letter-spacing: 0;
  color: var(--ink);
  margin-bottom: 1rem;
}

.quiz-options { display: flex; flex-direction: column; gap: 0.5rem; }

.quiz-option {
  display: block;
  padding: 0.8rem 1rem;
  background: var(--bone);
  border: 2px solid transparent;
  border-radius: var(--radius);
  cursor: pointer;
  font-size: 0.95rem;
  transition: all 0.2s;
}

.quiz-option:hover { border-color: var(--oil); background: rgba(255, 140, 26, 0.05); }
.quiz-option.selected { border-color: var(--oil); background: rgba(255, 140, 26, 0.1); }
.quiz-option.correct { border-color: #7fc97f; background: rgba(127, 201, 127, 0.15); }
.quiz-option.incorrect { border-color: var(--warning); background: rgba(212, 57, 46, 0.1); }
.quiz-option input { margin-right: 0.7rem; accent-color: var(--oil); }

.quiz-feedback {
  margin-top: 0.8rem;
  padding: 0.8rem 1rem;
  font-size: 0.9rem;
  border-radius: var(--radius);
  display: none;
}

.quiz-feedback.show { display: block; }
.quiz-feedback.correct { background: rgba(127, 201, 127, 0.15); color: #2d5a2d; }
.quiz-feedback.incorrect { background: rgba(212, 57, 46, 0.1); color: var(--warning); }

.quiz-result {
  text-align: center;
  padding: 2.5rem;
  background: var(--white);
  border-radius: var(--radius);
  margin-top: 2rem;
  border-top: 4px solid var(--oil);
}

.quiz-result h3 {
  font-family: var(--font-display);
  font-size: 2rem;
  margin-bottom: 1rem;
}

.quiz-result p {
  font-size: 1.1rem;
  margin-bottom: 2rem;
  color: var(--steel);
}

.quiz-result .btn { margin: 0 0.5rem; }

/* ----- Module Footer Nav ----- */
.module-footer {
  margin-top: 5rem;
  padding-top: 3rem;
  border-top: 2px solid var(--ink);
}

.module-nav {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1.5rem;
}

.module-nav-link {
  display: block;
  padding: 1.5rem;
  background: var(--white);
  border: var(--border);
  border-radius: var(--radius);
  transition: all 0.3s;
}

.module-nav-link small {
  display: block;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--concrete);
  margin-bottom: 0.3rem;
}

.module-nav-link strong {
  font-family: var(--font-display);
  font-size: 1.1rem;
  color: var(--ink);
}

.module-nav-next { text-align: right; }
.module-nav-link:hover { background: var(--ink); color: var(--paper); border-color: var(--ink); }
.module-nav-link:hover strong { color: var(--oil); }

/* ----- Responsive ----- */
@media (max-width: 900px) {
  .module-content { grid-template-columns: 1fr; gap: 2rem; }
  .module-toc { position: static; }
  .timeline::before { left: 20px; }
  .timeline-item { grid-template-columns: 1fr; gap: 0.5rem; }
  .timeline-item::before { left: 14px; top: 5px; }
  .timeline-year { text-align: left; padding-left: 50px; padding-top: 0; }
  .timeline-item p { margin-left: 50px; }
  .comparison { grid-template-columns: 1fr; }
  .module-nav { grid-template-columns: 1fr; }
  .module-nav-next { text-align: left; }
}