/* =============================================
   PART 04 — NOTEBOOKLM & LEARNING
   part04.css — Part-specific styles only
   ============================================= */

/* ── Forest green palette ── */
:root {
  --forest:     #0D2B1E;
  --forest-mid: #1A5C3A;
  --forest-lt:  #2D8A5C;
  --forest-bg:  #E8F5EF;
  --forest-bd:  #A8D5BC;
}

/* ── Section forest variant ── */
.section--forest { background: var(--forest); }
.section--forest .s-label { color: var(--forest-lt); border-color: var(--forest-mid); }
.section--forest .section-h2 { color: #fff; }
.section--forest p,
.section--forest li { color: rgba(255,255,255,0.72); }

/* ── Hero: forest green variant ── */
.hero--green .hero-left,
.hero--green .hero-right { background: var(--forest); }
.hero--green .part-divider { background: rgba(255,255,255,0.12); color: rgba(255,255,255,0.5); }
.hero--green .part-label { color: rgba(255,255,255,0.35); }
.hero--green .hero-h1 { color: #fff; }
.hero--green .hero-lead { color: rgba(255,255,255,0.68); }
.hero--green .hero-cta-primary {
  background: var(--forest-lt);
  color: #fff;
  border-color: var(--forest-lt);
}
.hero--green .hero-cta-primary:hover { background: var(--forest-mid); border-color: var(--forest-mid); }
.hero--green .hero-cta-secondary { color: rgba(255,255,255,0.75); border-color: rgba(255,255,255,0.25); }
.hero--green .hero-cta-secondary:hover { color: #fff; border-color: rgba(255,255,255,0.65); }

/* ── Hero Diagram ── */
.hero-diagram-card {
  width: 100%;
  max-width: 460px;
  margin: 0 auto;
  background: rgba(255,255,255,0.04);
  border: 1px solid rgba(45,138,92,0.3);
  border-radius: 12px;
  padding: 2.5rem 1.5rem 2rem;
}
.nlm-diagram {
  display: flex;
  align-items: center;
  gap: 0;
  width: 100%;
}
.nlm-sources-col,
.nlm-outputs-col {
  display: flex;
  flex-direction: column;
  gap: 8px;
  flex: 0 0 auto;
}
.nlm-pill {
  font-family: 'Outfit', sans-serif;
  font-size: 0.65rem;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  padding: 5px 10px;
  border-radius: 20px;
  white-space: nowrap;
  background: rgba(45,138,92,0.18);
  border: 1px solid rgba(45,138,92,0.4);
  color: rgba(255,255,255,0.65);
}
.nlm-pill-out {
  animation: outputPulse 3s ease-in-out infinite;
}
.nlm-pill-out:nth-child(1) { animation-delay: 0.0s; }
.nlm-pill-out:nth-child(2) { animation-delay: 0.4s; }
.nlm-pill-out:nth-child(3) { animation-delay: 0.8s; }
.nlm-pill-out:nth-child(4) { animation-delay: 1.2s; }
.nlm-pill-out:nth-child(5) { animation-delay: 1.6s; }
@keyframes outputPulse {
  0%, 100% { border-color: rgba(45,138,92,0.4); background: rgba(45,138,92,0.18); color: rgba(255,255,255,0.65); }
  50%       { border-color: rgba(45,138,92,0.85); background: rgba(45,138,92,0.32); color: rgba(255,255,255,0.95); }
}

.nlm-flow-zone {
  flex: 1;
  display: flex;
  flex-direction: column;
  justify-content: center;
  gap: 6px;
  padding: 0 6px;
  align-self: stretch;
}
.nlm-flow-line {
  height: 1px;
  background: rgba(45,138,92,0.2);
  position: relative;
  overflow: hidden;
}
.nlm-flow-line::after {
  content: '';
  position: absolute;
  top: 0; left: -60%;
  width: 60%;
  height: 100%;
  background: linear-gradient(90deg, transparent, var(--forest-lt), transparent);
  animation: flowTravel 2.2s linear infinite;
}
.nlm-flow-zone.nlm-flow-out .nlm-flow-line::after {
  animation-delay: 1.1s;
}
.nlm-flow-line:nth-child(2)::after { animation-delay: 0.4s; }
.nlm-flow-line:nth-child(3)::after { animation-delay: 0.8s; }
@keyframes flowTravel {
  0%   { left: -60%; }
  100% { left: 160%; }
}

.nlm-center-orb {
  flex: 0 0 auto;
  width: 62px;
  height: 62px;
  border-radius: 50%;
  background: var(--forest-mid);
  border: 2px solid var(--forest-lt);
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
  font-family: 'Playfair Display', serif;
  font-size: 1.5rem;
  color: #fff;
  animation: orbPulse 3s ease-in-out infinite;
  flex-shrink: 0;
}
.nlm-center-orb::before {
  content: '';
  position: absolute;
  inset: -10px;
  border-radius: 50%;
  border: 1px solid rgba(45,138,92,0.35);
  animation: ringFade 3s ease-out infinite;
}
@keyframes orbPulse {
  0%, 100% { box-shadow: 0 0 0 0 rgba(45,138,92,0.5); }
  50%       { box-shadow: 0 0 0 14px rgba(45,138,92,0); }
}
@keyframes ringFade {
  0%   { transform: scale(1); opacity: 0.6; }
  100% { transform: scale(1.7); opacity: 0; }
}
.nlm-diagram-label {
  font-family: 'Outfit', sans-serif;
  font-size: 0.65rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: rgba(255,255,255,0.3);
  text-align: center;
  margin-top: 1.25rem;
}

/* ── Section 2: What is NotebookLM ── */
.nlm-what-layout {
  display: grid;
  grid-template-columns: 1fr 1.6fr;
  gap: 5rem;
  align-items: start;
}
.nlm-sticky-left { position: sticky; top: 90px; }
.nlm-distinction-box {
  margin-top: 2rem;
  padding: 1.25rem 1.5rem;
  border: 1.5px solid var(--forest-bd);
  border-left: 4px solid var(--forest-lt);
  background: var(--forest-bg);
  border-radius: 0 6px 6px 0;
}
.nlm-distinction-box p {
  font-family: 'Playfair Display', serif;
  font-style: italic;
  font-size: 1rem;
  line-height: 1.55;
  color: var(--forest-mid);
  margin: 0;
}
.nlm-body-text p {
  font-size: 1rem;
  line-height: 1.8;
  color: rgba(26,26,23,0.72);
  margin-bottom: 1.25rem;
}
.nlm-body-text p:last-child { margin-bottom: 0; }
.green-callout {
  margin-top: 2rem;
  padding: 1.25rem 1.5rem;
  background: var(--forest-bg);
  border-left: 4px solid var(--forest-lt);
  border-radius: 0 4px 4px 0;
}
.green-callout p {
  color: var(--forest-mid);
  font-size: 0.925rem;
  line-height: 1.7;
  margin: 0;
}

/* ── Section 3: Studio ── */
.studio-section-header { text-align: center; margin-bottom: 3rem; }
.studio-section-header h2 {
  font-family: 'Playfair Display', serif;
  font-size: clamp(1.5rem, 3vw, 2.2rem);
  color: #fff;
  margin-bottom: 0.75rem;
}
.studio-section-header p {
  color: rgba(255,255,255,0.55);
  font-size: 0.95rem;
  max-width: 620px;
  margin: 0 auto;
  line-height: 1.65;
}
.studio-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.25rem;
}
.studio-card {
  position: relative;
  overflow: hidden;
  height: 220px;
  border-radius: 8px;
  background: rgba(255,255,255,0.05);
  border: 1px solid rgba(255,255,255,0.08);
  cursor: pointer;
  transition: border-color 0.25s ease;
}
.studio-card:hover,
.studio-card.active { border-color: rgba(45,138,92,0.65); }

.studio-card-front {
  position: absolute;
  inset: 0;
  padding: 1.5rem;
  display: flex;
  flex-direction: column;
  gap: 0.6rem;
  transition: transform 0.25s ease;
}
.studio-card:hover .studio-card-front,
.studio-card.active .studio-card-front { transform: translateX(-100%); }

.studio-card-icon {
  width: 32px;
  height: 32px;
  flex-shrink: 0;
  opacity: 0.8;
}
.studio-card-num {
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.6rem;
  color: var(--forest-lt);
  letter-spacing: 0.1em;
}
.studio-card-name {
  font-family: 'Playfair Display', serif;
  font-size: 0.95rem;
  color: #fff;
  line-height: 1.3;
}
.studio-card-desc {
  font-size: 0.78rem;
  color: rgba(255,255,255,0.5);
  line-height: 1.5;
}

.studio-card-back {
  position: absolute;
  inset: 0;
  padding: 1.25rem 1.5rem;
  background: var(--forest-mid);
  transform: translateX(100%);
  transition: transform 0.25s ease;
  overflow-y: auto;
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
  scrollbar-width: none;
}
.studio-card-back::-webkit-scrollbar { display: none; }
.studio-card:hover .studio-card-back,
.studio-card.active .studio-card-back { transform: translateX(0); }

.sc-back-name {
  font-family: 'Playfair Display', serif;
  font-size: 0.88rem;
  color: #fff;
  margin-bottom: 0.15rem;
}
.sc-back-body {
  font-size: 0.74rem;
  color: rgba(255,255,255,0.68);
  line-height: 1.55;
  flex-grow: 1;
}
.sc-back-example {
  padding-top: 0.6rem;
  border-top: 1px solid rgba(255,255,255,0.15);
  margin-top: 0.4rem;
}
.sc-back-example-label {
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.58rem;
  color: var(--forest-lt);
  letter-spacing: 0.08em;
  text-transform: uppercase;
  margin-bottom: 0.3rem;
}
.sc-back-example p {
  font-size: 0.7rem;
  color: rgba(255,255,255,0.55);
  line-height: 1.5;
  font-style: italic;
  margin: 0;
}

/* ── Section 4: Learning ── */
.section-h2-split {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 2rem 4rem;
  align-items: start;
  margin-bottom: 2.5rem;
}
.section-h2-split .section-h2 { margin-bottom: 0; }
.section-h2-split-right {
  font-size: 1rem;
  line-height: 1.7;
  color: rgba(26,26,23,0.65);
  padding-top: 0.25rem;
}
.learner-strip {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1.25rem;
  margin-bottom: 3rem;
}
.learner-card {
  background: #fff;
  border-left: 4px solid var(--teal);
  border-radius: 0 6px 6px 0;
  padding: 1.5rem 1.25rem;
  box-shadow: 0 2px 12px rgba(0,0,0,0.05);
}
.learner-card--teal  { border-left-color: var(--teal); }
.learner-card--amber { border-left-color: var(--amber); }
.learner-card--coral { border-left-color: var(--coral); }
.learner-card--green { border-left-color: var(--forest-lt); }
.learner-type {
  font-family: 'Playfair Display', serif;
  font-size: 1.05rem;
  color: var(--ink);
  margin-bottom: 0.65rem;
}
.learner-card p {
  font-size: 0.85rem;
  line-height: 1.65;
  color: rgba(26,26,23,0.68);
  margin: 0;
}
.learner-body-cols {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 3rem;
}
.learner-body-cols p {
  font-size: 0.975rem;
  line-height: 1.78;
  color: rgba(26,26,23,0.7);
  margin-bottom: 1.25rem;
}
.learner-body-cols p:last-child { margin-bottom: 0; }

/* ── Section 5: Use Cases ── */
.use-cases-list { display: flex; flex-direction: column; }
.use-case-row {
  display: grid;
  grid-template-columns: 56px 1fr 1.2fr;
  gap: 2rem 3rem;
  padding: 2.5rem 0;
  border-bottom: 1px solid rgba(255,255,255,0.09);
  align-items: start;
}
.use-case-row:first-child { border-top: 1px solid rgba(255,255,255,0.09); }
.uc-number {
  font-family: 'Playfair Display', serif;
  font-size: 3rem;
  line-height: 1;
  color: rgba(255,255,255,0.1);
  user-select: none;
  text-align: right;
  padding-top: 0.2rem;
}
.uc-title {
  font-family: 'Playfair Display', serif;
  font-size: 1.15rem;
  color: #fff;
  margin-bottom: 0.65rem;
}
.uc-desc {
  font-size: 0.875rem;
  line-height: 1.72;
  color: rgba(255,255,255,0.58);
  margin: 0;
}
.uc-steps {
  display: flex;
  flex-direction: column;
  gap: 0.6rem;
  padding-top: 0.2rem;
}
.uc-step {
  display: flex;
  align-items: flex-start;
  gap: 0.75rem;
}
.uc-step-num {
  flex-shrink: 0;
  width: 22px;
  height: 22px;
  border-radius: 50%;
  background: rgba(26,92,58,0.6);
  border: 1px solid var(--forest-lt);
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.58rem;
  color: var(--forest-lt);
  margin-top: 2px;
}
.uc-step-text {
  font-size: 0.82rem;
  line-height: 1.6;
  color: rgba(255,255,255,0.62);
}

/* ── Section 6: Interactive Mode ── */
.interactive-layout {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 5rem;
  align-items: center;
}

/* Audio player mockup */
.audio-mockup {
  background: var(--forest);
  border-radius: 14px;
  padding: 1.75rem;
  border: 1px solid rgba(45,138,92,0.28);
  box-shadow: 0 12px 48px rgba(13,43,30,0.22);
}
.mockup-titlebar {
  display: flex;
  align-items: center;
  gap: 6px;
  margin-bottom: 1.5rem;
}
.mockup-dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
}
.mockup-dot:nth-child(1) { background: rgba(255,95,87,0.6); }
.mockup-dot:nth-child(2) { background: rgba(255,189,46,0.6); }
.mockup-dot:nth-child(3) { background: rgba(40,200,64,0.6); }
.mockup-app-title {
  margin-left: auto;
  font-family: 'Outfit', sans-serif;
  font-size: 0.65rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: rgba(255,255,255,0.3);
}
.hosts-row {
  display: flex;
  gap: 2rem;
  align-items: flex-end;
  justify-content: center;
  margin-bottom: 1.25rem;
}
.host-wrap {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.4rem;
}
.host-eq {
  display: flex;
  gap: 3px;
  align-items: flex-end;
  height: 36px;
}
.eq-bar {
  width: 4px;
  border-radius: 2px;
  background: var(--forest-lt);
  transform-origin: bottom;
  animation: eqPulse 0.9s ease-in-out infinite alternate;
}
.eq-bar:nth-child(1) { height: 12px; animation-delay: 0.00s; }
.eq-bar:nth-child(2) { height: 22px; animation-delay: 0.13s; }
.eq-bar:nth-child(3) { height: 16px; animation-delay: 0.26s; }
.eq-bar:nth-child(4) { height: 28px; animation-delay: 0.39s; }
.eq-bar:nth-child(5) { height: 18px; animation-delay: 0.52s; }
.host-wrap:last-child .eq-bar { background: rgba(45,138,92,0.7); }
.host-wrap:last-child .eq-bar:nth-child(1) { height: 20px; animation-delay: 0.1s; }
.host-wrap:last-child .eq-bar:nth-child(2) { height: 14px; animation-delay: 0.25s; }
.host-wrap:last-child .eq-bar:nth-child(3) { height: 30px; animation-delay: 0.4s; }
.host-wrap:last-child .eq-bar:nth-child(4) { height: 18px; animation-delay: 0.55s; }
.host-wrap:last-child .eq-bar:nth-child(5) { height: 24px; animation-delay: 0.7s; }
@keyframes eqPulse {
  0%   { transform: scaleY(0.25); }
  100% { transform: scaleY(1); }
}
.host-label {
  font-family: 'Outfit', sans-serif;
  font-size: 0.62rem;
  color: rgba(255,255,255,0.3);
  letter-spacing: 0.04em;
}
.host-divider {
  font-size: 0.65rem;
  color: rgba(255,255,255,0.15);
  padding-bottom: 0.5rem;
}
.mockup-progress-bar {
  height: 3px;
  background: rgba(255,255,255,0.08);
  border-radius: 2px;
  margin-bottom: 1rem;
  overflow: hidden;
}
.mockup-progress-fill {
  height: 100%;
  width: 38%;
  background: var(--forest-lt);
  border-radius: 2px;
}
.mockup-join-btn {
  display: block;
  width: 100%;
  padding: 0.55rem 1rem;
  background: rgba(26,92,58,0.5);
  border: 1px solid var(--forest-lt);
  border-radius: 6px;
  color: var(--forest-lt);
  font-family: 'Outfit', sans-serif;
  font-size: 0.72rem;
  letter-spacing: 0.05em;
  text-align: center;
  margin-bottom: 0.75rem;
  cursor: pointer;
  transition: background 0.2s ease;
}
.mockup-join-btn:hover { background: rgba(26,92,58,0.75); }
.mockup-interrupt {
  background: rgba(255,255,255,0.04);
  border: 1px solid rgba(255,255,255,0.1);
  border-radius: 6px;
  padding: 0.6rem 0.8rem;
}
.mockup-interrupt-label {
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.55rem;
  color: rgba(255,255,255,0.25);
  letter-spacing: 0.1em;
  text-transform: uppercase;
  margin-bottom: 0.35rem;
}
.mockup-interrupt-text {
  font-family: 'Outfit', sans-serif;
  font-size: 0.78rem;
  color: rgba(255,255,255,0.45);
  font-style: italic;
  line-height: 1.5;
}

.interactive-content h3 {
  font-family: 'Playfair Display', serif;
  font-size: 1.55rem;
  color: var(--ink);
  margin-bottom: 1rem;
}
.interactive-content p {
  font-size: 0.95rem;
  line-height: 1.75;
  color: rgba(26,26,23,0.7);
  margin-bottom: 1.25rem;
}
.interactive-content h4 {
  font-family: 'Outfit', sans-serif;
  font-size: 0.72rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--ink);
  margin: 1.5rem 0 0.75rem;
}
.interactive-ways {
  list-style: none;
  padding: 0;
  margin: 0;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}
.interactive-ways li {
  padding: 0.6rem 0.75rem 0.6rem 1rem;
  border-left: 3px solid var(--forest-lt);
  background: var(--forest-bg);
  font-size: 0.875rem;
  line-height: 1.6;
  color: rgba(26,26,23,0.7);
}
.interactive-ways li strong { color: var(--ink); }

/* ── Section 7: What it's not (amber strip) ── */
.nlm-not-strip {
  background: var(--amber);
  padding: 3.5rem var(--section-pad-h);
}
.nlm-not-inner {
  max-width: 800px;
  margin: 0 auto;
  text-align: center;
}
.nlm-not-label {
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.62rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: rgba(26,26,23,0.45);
  margin-bottom: 1.25rem;
}
.nlm-not-strip p {
  font-size: 0.95rem;
  line-height: 1.78;
  color: rgba(26,26,23,0.78);
  margin-bottom: 1rem;
  font-style: italic;
}
.nlm-not-strip p:last-child { margin-bottom: 0; }
.nlm-not-strip strong {
  font-style: normal;
  color: var(--ink);
}

/* ── Section 8: Setup Guide ── */
.setup-header { text-align: center; margin-bottom: 3.5rem; }
.setup-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 2rem 4rem;
}
/* Even steps shift down for stagger */
.setup-grid .setup-step:nth-child(even) { margin-top: 2rem; }

.setup-step {
  background: #fff;
  border: 1px solid var(--rule);
  border-radius: 8px;
  padding: 1.75rem;
  position: relative;
}
.setup-step-num {
  font-family: 'Playfair Display', serif;
  font-size: 3.5rem;
  line-height: 1;
  color: rgba(26,26,23,0.06);
  position: absolute;
  top: 1rem;
  right: 1.25rem;
}
.setup-step h3 {
  font-family: 'Playfair Display', serif;
  font-size: 1.05rem;
  color: var(--ink);
  margin-bottom: 0.65rem;
  padding-right: 3rem;
}
.setup-step p {
  font-size: 0.875rem;
  line-height: 1.72;
  color: rgba(26,26,23,0.66);
  margin-bottom: 0.9rem;
}
.setup-step p:last-of-type { margin-bottom: 0.75rem; }
.setup-tip {
  display: inline-flex;
  align-items: flex-start;
  gap: 0.5rem;
  background: var(--forest-bg);
  border: 1px solid var(--forest-bd);
  border-radius: 20px;
  padding: 0.35rem 0.85rem;
  font-family: 'Outfit', sans-serif;
  font-size: 0.72rem;
  line-height: 1.5;
  color: var(--forest-mid);
}
.setup-tip::before {
  content: '→';
  color: var(--forest-lt);
  font-size: 0.75rem;
  flex-shrink: 0;
  margin-top: 1px;
}

/* ── Section 9: Pull Quote (forest green) ── */
.nlm-quote-section {
  background: var(--forest);
  padding: 5rem var(--section-pad-h);
  text-align: center;
}
.nlm-quote-inner { max-width: 800px; margin: 0 auto; }
.nlm-quote-mark {
  font-family: 'Playfair Display', serif;
  font-size: 5rem;
  line-height: 0.5;
  color: var(--forest-lt);
  display: block;
  margin-bottom: 1.5rem;
}
.nlm-quote-text {
  font-family: 'Playfair Display', serif;
  font-style: italic;
  font-size: clamp(1.1rem, 2.2vw, 1.45rem);
  line-height: 1.65;
  color: rgba(255,255,255,0.88);
  margin-bottom: 1.5rem;
}
.nlm-quote-attr {
  font-family: 'Outfit', sans-serif;
  font-size: 0.78rem;
  color: rgba(255,255,255,0.38);
  letter-spacing: 0.05em;
}

/* ── Responsive ── */
@media (max-width: 1100px) {
  .studio-grid { grid-template-columns: repeat(2, 1fr); }
  .learner-strip { grid-template-columns: repeat(2, 1fr); }
  .section-h2-split { grid-template-columns: 1fr; gap: 1rem; }
  .use-case-row { grid-template-columns: 48px 1fr; }
  .uc-steps { grid-column: 1 / -1; padding-left: 4rem; }
  .learner-body-cols { gap: 2rem; }
}
@media (max-width: 900px) {
  .nlm-what-layout { grid-template-columns: 1fr; gap: 2rem; }
  .nlm-sticky-left { position: static; }
  .learner-strip { grid-template-columns: 1fr 1fr; }
  .learner-body-cols { grid-template-columns: 1fr; gap: 0; }
  .use-case-row { grid-template-columns: 1fr; }
  .uc-number { display: none; }
  .uc-steps { padding-left: 0; }
  .interactive-layout { grid-template-columns: 1fr; gap: 2.5rem; }
  .setup-grid { grid-template-columns: 1fr; }
  .setup-grid .setup-step:nth-child(even) { margin-top: 0; }
}
@media (max-width: 640px) {
  .studio-grid { grid-template-columns: 1fr 1fr; }
  .learner-strip { grid-template-columns: 1fr; }
  .hero-diagram-card { display: none; }
}
@media (max-width: 480px) {
  .studio-grid { grid-template-columns: 1fr; }
  .section-h2-split .section-h2 { font-size: 1.6rem; }
}