/* ────────────────────────────────────────────────────────────────────────────
   Lesson page styles — sits on top of styles.css
   Editorial article layout: sticky TOC sidebar + ~640px reading column
   ──────────────────────────────────────────────────────────────────────────── */

.lesson-root {
  background: var(--bg, #fafaf7);
  color: var(--ink, #111);
  min-height: 100vh;
  --max-read: 660px;
}

/* Top nav — minimal back-link bar */
.lesson-nav {
  position: sticky; top: 0; z-index: 40;
  display: flex; align-items: center; justify-content: space-between;
  padding: 16px 32px;
  background: color-mix(in srgb, var(--bg) 88%, transparent);
  backdrop-filter: blur(14px) saturate(140%);
  -webkit-backdrop-filter: blur(14px) saturate(140%);
  border-bottom: 1px solid var(--rule);
  font-size: 13.5px;
}
.lesson-nav a { color: var(--ink-2); text-decoration: none; transition: color 0.15s; }
.lesson-nav a:hover { color: var(--ink); }
.lesson-nav-left { display: flex; align-items: center; gap: 10px; }
.lesson-nav-center {
  display: flex; align-items: center; gap: 8px;
  color: var(--ink); font-weight: 500;
}
.lesson-nav-center svg path { stroke: none; }
.lesson-nav-right { display: flex; align-items: center; gap: 18px; }
.lesson-nav-progress {
  width: 90px; height: 3px; background: var(--rule);
  border-radius: 100px; overflow: hidden; position: relative;
}
.lesson-nav-progress i {
  display: block; height: 100%; background: var(--accent);
  width: 0%; transition: width 0.1s linear;
}
.lesson-nav-share {
  appearance: none; border: 1px solid var(--ink);
  background: transparent; color: var(--ink);
  padding: 6px 12px; border-radius: 100px;
  font: inherit; font-size: 12.5px; font-weight: 500;
  cursor: pointer;
}
.lesson-nav-share:hover { background: var(--ink); color: var(--bg); }

/* Hero header */
.lesson-header {
  max-width: 880px; margin: 0 auto;
  padding: 64px 32px 36px;
}
.lesson-eyebrow {
  display: inline-flex; align-items: center; gap: 10px;
  font-size: 12px; letter-spacing: 0.08em; text-transform: uppercase;
  color: var(--ink-2);
  margin-bottom: 28px;
}
.lesson-eyebrow .eyebrow-num {
  font-family: "JetBrains Mono", ui-monospace, monospace;
  font-size: 11px; color: var(--ink-3);
  padding: 3px 8px; border: 1px solid var(--rule);
  border-radius: 100px;
}
.lesson-eyebrow .eyebrow-dot {
  width: 4px; height: 4px; border-radius: 50%;
  background: var(--ink-3);
}
.lesson-title {
  font-family: "Instrument Serif", "Times New Roman", serif;
  font-weight: 400;
  font-size: clamp(36px, 4.8vw, 64px);
  line-height: 1.14;
  letter-spacing: -0.025em;
  margin: 0 0 32px;
  text-wrap: balance;
  max-width: 20ch;
  /* Instrument Serif italic descenders drop ~0.25em below baseline —
     reserve actual space rather than relying on line-height */
  padding-bottom: 0.32em;
}
.lesson-title em {
  font-style: italic;
  color: var(--accent);
}
.lesson-deck {
  font-size: clamp(18px, 1.6vw, 22px);
  line-height: 1.45;
  color: var(--ink-2);
  max-width: 60ch;
  margin: 0 0 32px;
  text-wrap: pretty;
}

.lesson-byline {
  display: flex; align-items: center; gap: 14px;
  padding: 18px 0 0;
  border-top: 1px solid var(--rule);
}
.byline-avatar {
  width: 40px; height: 40px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--accent) 0%, color-mix(in srgb, var(--accent) 60%, #111) 100%);
  flex: 0 0 40px;
  display: flex; align-items: center; justify-content: center;
  color: white; font-weight: 500; font-size: 14px;
  letter-spacing: 0.02em;
}
.byline-text { display: flex; flex-direction: column; gap: 2px; }
.byline-text strong { font-weight: 500; font-size: 14px; color: var(--ink); }
.byline-text span { font-size: 12.5px; color: var(--ink-3); }
.byline-tags {
  display: flex; gap: 6px; margin-left: auto;
  flex-wrap: wrap; justify-content: flex-end;
}
.byline-tag {
  font-size: 11.5px;
  padding: 4px 10px;
  border: 1px solid var(--rule);
  border-radius: 100px;
  color: var(--ink-2);
  background: var(--card-bg);
}

/* Two-column layout */
.lesson-layout {
  max-width: 1280px; margin: 0 auto;
  padding: 24px 32px 80px;
  display: grid;
  grid-template-columns: 220px 1fr;
  gap: 64px;
  align-items: flex-start;
}
.lesson-toc {
  position: sticky; top: 80px;
  padding-top: 8px;
  font-size: 13px;
  align-self: flex-start;
}
.toc-label {
  font-size: 11px; letter-spacing: 0.1em; text-transform: uppercase;
  color: var(--ink-3); font-weight: 500;
  margin-bottom: 14px;
}
.lesson-toc ol {
  list-style: none; padding: 0; margin: 0;
  counter-reset: toc;
}
.lesson-toc li { counter-increment: toc; }
.lesson-toc a {
  display: flex; gap: 10px;
  padding: 7px 0;
  color: var(--ink-2);
  text-decoration: none;
  line-height: 1.4;
  border-left: 2px solid transparent;
  padding-left: 12px;
  margin-left: -14px;
  transition: color 0.15s, border-color 0.15s;
}
.lesson-toc a::before {
  content: counter(toc, decimal-leading-zero);
  font-family: "JetBrains Mono", ui-monospace, monospace;
  font-size: 11px;
  color: var(--ink-3);
  letter-spacing: 0;
}
.lesson-toc a:hover { color: var(--ink); }
.lesson-toc a.active {
  color: var(--ink);
  border-left-color: var(--accent);
  font-weight: 500;
}

/* Article content */
.lesson-content { min-width: 0; }
.lesson-section {
  scroll-margin-top: 80px;
  padding-bottom: 72px;
}
.lesson-section + .lesson-section { padding-top: 0; }
.lesson-section-head {
  display: flex; align-items: baseline; gap: 18px;
  margin-bottom: 28px;
  padding-bottom: 18px;
  border-bottom: 1px solid var(--rule);
}
.lesson-section-num {
  font-family: "JetBrains Mono", ui-monospace, monospace;
  font-size: 13px; color: var(--ink-3);
  letter-spacing: 0;
  font-variant-numeric: tabular-nums;
}
.lesson-section-h {
  font-family: "Instrument Serif", serif;
  font-weight: 400;
  font-size: clamp(28px, 3vw, 38px);
  line-height: 1.05;
  letter-spacing: -0.02em;
  margin: 0;
  flex: 1;
}
.lesson-prose {
  max-width: var(--max-read);
  font-size: 17px;
  line-height: 1.6;
  color: var(--ink);
}
.lesson-prose > * + * { margin-top: 20px; }
.lesson-prose p { margin: 0; text-wrap: pretty; }
.lesson-prose strong { font-weight: 600; color: var(--ink); }
.lesson-prose em { color: var(--ink); font-style: italic; }
.lesson-prose a {
  color: var(--ink);
  text-decoration: underline;
  text-decoration-color: color-mix(in srgb, var(--accent) 60%, transparent);
  text-underline-offset: 3px;
  text-decoration-thickness: 1.5px;
}
.lesson-prose a:hover { text-decoration-color: var(--accent); }
.lesson-prose ul, .lesson-prose ol {
  padding-left: 22px;
  margin: 0;
  display: flex; flex-direction: column; gap: 6px;
}
.lesson-prose li::marker { color: var(--ink-3); }

/* Pull quote */
.pullquote {
  margin: 32px 0;
  padding: 0 0 0 24px;
  border-left: 2px solid var(--accent);
  font-family: "Instrument Serif", serif;
  font-size: 24px;
  line-height: 1.3;
  color: var(--ink);
  letter-spacing: -0.01em;
  max-width: var(--max-read);
  font-style: italic;
}

/* Video player mockup */
.video-player {
  position: relative;
  width: 100%;
  aspect-ratio: 16 / 9;
  border-radius: 16px;
  overflow: hidden;
  background: #0a0a0a;
  box-shadow: 0 20px 60px -20px rgba(0,0,0,0.4);
  cursor: pointer;
  transition: transform 0.2s;
}
.video-player:hover { transform: translateY(-2px); }
.video-player-poster {
  position: absolute; inset: 0;
  background: radial-gradient(ellipse at 30% 40%, #2a2520 0%, #0a0a0a 70%);
  display: flex; align-items: center; justify-content: center;
}
.video-player-poster svg { width: 100%; height: 100%; opacity: 0.6; }
.video-player-play {
  position: absolute; top: 50%; left: 50%;
  transform: translate(-50%, -50%);
  width: 72px; height: 72px;
  border-radius: 50%;
  background: rgba(255,255,255,0.95);
  display: flex; align-items: center; justify-content: center;
  box-shadow: 0 8px 24px rgba(0,0,0,0.3);
  transition: transform 0.2s;
}
.video-player:hover .video-player-play { transform: translate(-50%, -50%) scale(1.06); }
.video-player-play::after {
  content: "";
  width: 0; height: 0;
  margin-left: 5px;
  border-left: 18px solid #111;
  border-top: 11px solid transparent;
  border-bottom: 11px solid transparent;
}
.video-player-meta {
  position: absolute;
  bottom: 18px; left: 22px; right: 22px;
  display: flex; align-items: flex-end; justify-content: space-between;
  gap: 16px;
  color: white;
  z-index: 2;
}
.video-player-title {
  font-family: "Instrument Serif", serif;
  font-size: 24px;
  line-height: 1.05;
  letter-spacing: -0.01em;
  max-width: 70%;
  display: -webkit-box;
  -webkit-box-orient: vertical;
  -webkit-line-clamp: 2;
  overflow: hidden;
  padding-bottom: 2px;
}
.video-player-time {
  font-family: "JetBrains Mono", monospace;
  font-size: 12px;
  background: rgba(0,0,0,0.5);
  padding: 4px 8px;
  border-radius: 4px;
  border: 1px solid rgba(255,255,255,0.1);
}
.video-player-scrubber {
  position: absolute; bottom: 0; left: 0; right: 0;
  height: 4px; background: rgba(255,255,255,0.18);
}
.video-player-scrubber::after {
  content: "";
  display: block; height: 100%;
  width: 22%;
  background: var(--accent);
}

/* Code block */
.code-block {
  position: relative;
  background: #1a1715;
  color: #e8e4dc;
  border-radius: 12px;
  overflow: hidden;
  font-family: "JetBrains Mono", ui-monospace, monospace;
  font-size: 13px;
  line-height: 1.55;
  max-width: var(--max-read);
}
.code-head {
  display: flex; align-items: center; justify-content: space-between;
  padding: 10px 14px 10px 16px;
  background: rgba(0,0,0,0.18);
  border-bottom: 1px solid rgba(255,255,255,0.06);
  color: rgba(255,255,255,0.5);
  font-size: 11.5px;
}
.code-head-left { display: flex; align-items: center; gap: 8px; }
.code-head-filename {
  color: rgba(255,255,255,0.78);
  font-size: 12px;
}
.code-head-lang {
  font-size: 10.5px;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  padding: 2px 7px;
  background: rgba(255,255,255,0.06);
  border-radius: 4px;
}
.code-copy {
  appearance: none;
  background: transparent;
  border: 1px solid rgba(255,255,255,0.1);
  color: rgba(255,255,255,0.7);
  padding: 4px 10px;
  border-radius: 6px;
  font: inherit; font-size: 11px;
  cursor: pointer;
  display: inline-flex; align-items: center; gap: 6px;
  transition: all 0.15s;
}
.code-copy:hover { background: rgba(255,255,255,0.08); color: white; border-color: rgba(255,255,255,0.2); }
.code-copy.copied { background: var(--accent); border-color: var(--accent); color: white; }

.code-body {
  padding: 18px 20px;
  overflow-x: auto;
  white-space: pre;
  tab-size: 2;
  scrollbar-width: thin;
  scrollbar-color: rgba(255,255,255,0.15) transparent;
}
.code-body::-webkit-scrollbar { height: 8px; }
.code-body::-webkit-scrollbar-thumb { background: rgba(255,255,255,0.15); border-radius: 4px; }

/* token colors */
.tk-c   { color: #7a7065; font-style: italic; } /* comment */
.tk-k   { color: #d59a76; } /* keyword */
.tk-s   { color: #c4d68d; } /* string */
.tk-n   { color: #b8aef7; } /* number */
.tk-p   { color: #e8e4dc; } /* punctuation */
.tk-h   { color: #f0a875; font-weight: 500; } /* heading in markdown */
.tk-em  { color: #e8e4dc; font-weight: 500; } /* emphasis */

/* Inline code */
.lesson-prose code, .step-body code, .faq-q code {
  font-family: "JetBrains Mono", monospace;
  font-size: 0.88em;
  padding: 2px 6px;
  background: var(--chip-bg);
  border-radius: 5px;
  color: var(--ink);
}

/* Step blocks */
.step {
  display: grid;
  grid-template-columns: 56px 1fr;
  gap: 24px;
  padding: 28px 0;
  border-bottom: 1px solid var(--rule);
  align-items: flex-start;
}
.step:last-child { border-bottom: 0; }
.step-num {
  font-family: "Instrument Serif", serif;
  font-size: 44px;
  line-height: 1;
  color: var(--accent);
  font-style: italic;
}
.step-body { display: flex; flex-direction: column; gap: 16px; }
.step-h {
  font-family: "Instrument Serif", serif;
  font-size: 26px;
  font-weight: 400;
  letter-spacing: -0.015em;
  line-height: 1.15;
  margin: 0;
}
.step-body p { margin: 0; font-size: 16px; line-height: 1.55; color: var(--ink-2); }

/* Try-it card */
.try-card {
  border: 1px solid var(--rule);
  border-radius: 14px;
  background: var(--card-bg);
  overflow: hidden;
  max-width: var(--max-read);
}
.try-input-row {
  display: flex; align-items: center; gap: 8px;
  padding: 14px 16px;
  border-bottom: 1px solid var(--rule);
  background: color-mix(in srgb, var(--accent) 4%, var(--card-bg));
}
.try-prompt {
  font-family: "JetBrains Mono", monospace;
  font-size: 12.5px;
  color: var(--accent);
  flex-shrink: 0;
}
.try-cmd {
  flex: 1;
  font-family: "JetBrains Mono", monospace;
  font-size: 13px;
  color: var(--ink);
  background: transparent;
  border: 0; outline: 0;
}
.try-go {
  appearance: none;
  background: var(--ink); color: var(--bg);
  border: 0; border-radius: 6px;
  padding: 6px 12px;
  font: inherit; font-size: 12px; font-weight: 500;
  cursor: pointer;
}
.try-output {
  padding: 18px 20px;
  font-size: 14px;
  line-height: 1.6;
  color: var(--ink);
  display: flex; flex-direction: column; gap: 10px;
}
.try-output-status {
  display: flex; align-items: center; gap: 8px;
  font-family: "JetBrains Mono", monospace;
  font-size: 12px;
  color: var(--ink-3);
}
.try-output-status .dot {
  width: 6px; height: 6px; border-radius: 50%;
  background: var(--accent);
  animation: pulse 1.5s ease-in-out infinite;
}
.try-output-line { color: var(--ink-2); }
.try-output-line.done { color: var(--ink); }
.try-output-line.done::before { content: "✓ "; color: var(--accent); }

/* Example breakdown cards */
.example {
  border: 1px solid var(--rule);
  border-radius: 14px;
  background: var(--card-bg);
  overflow: hidden;
  max-width: var(--max-read);
}
.example + .example { margin-top: 16px; }
.example-head {
  display: flex; align-items: center; gap: 14px;
  padding: 16px 20px;
  border-bottom: 1px solid var(--rule);
  background: color-mix(in srgb, var(--ink) 2%, transparent);
}
.example-thumb {
  width: 48px; height: 48px;
  border-radius: 8px;
  flex: 0 0 48px;
  background: #1a1a1a;
  position: relative;
  overflow: hidden;
}
.example-thumb::after {
  content: ""; position: absolute;
  top: 50%; left: 50%;
  transform: translate(-50%, -50%);
  width: 0; height: 0;
  border-left: 10px solid white;
  border-top: 6px solid transparent;
  border-bottom: 6px solid transparent;
  margin-left: 2px;
  opacity: 0.85;
}
.example-meta {
  display: flex; flex-direction: column; gap: 2px;
  flex: 1;
  min-width: 0;
}
.example-creator {
  font-size: 14px; font-weight: 500; color: var(--ink);
}
.example-source {
  font-size: 12px; color: var(--ink-3);
  font-family: "JetBrains Mono", monospace;
}
.example-views {
  font-size: 12.5px; color: var(--ink-2);
  font-variant-numeric: tabular-nums;
}
.example-body {
  padding: 18px 20px 22px;
  display: flex; flex-direction: column; gap: 14px;
}
.example-row {
  display: grid;
  grid-template-columns: 96px 1fr;
  gap: 12px;
  align-items: baseline;
  font-size: 14px;
  line-height: 1.55;
}
.example-row-label {
  font-family: "JetBrains Mono", monospace;
  font-size: 11px;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  color: var(--ink-3);
}
.example-row-text { color: var(--ink); text-wrap: pretty; }
.example-row-text em {
  color: var(--accent);
  font-style: normal;
}

/* FAQ accordion */
.faq { display: flex; flex-direction: column; gap: 0; max-width: var(--max-read); }
.faq-item {
  border-bottom: 1px solid var(--rule);
}
.faq-item:first-child { border-top: 1px solid var(--rule); }
.faq-q {
  appearance: none;
  width: 100%;
  text-align: left;
  background: transparent;
  border: 0;
  padding: 22px 36px 22px 0;
  font: inherit;
  font-size: 17px;
  font-weight: 500;
  color: var(--ink);
  cursor: pointer;
  position: relative;
  display: block;
  transition: color 0.15s;
}
.faq-q:hover { color: var(--accent); }
.faq-q::after {
  content: "";
  position: absolute;
  right: 4px; top: 50%;
  width: 12px; height: 12px;
  background: 
    linear-gradient(currentColor, currentColor) center / 12px 1.5px no-repeat,
    linear-gradient(currentColor, currentColor) center / 1.5px 12px no-repeat;
  transform: translateY(-50%);
  transition: transform 0.2s;
  color: var(--ink-2);
}
.faq-item.open .faq-q::after {
  background: linear-gradient(currentColor, currentColor) center / 12px 1.5px no-repeat;
}
.faq-a {
  overflow: hidden;
  max-height: 0;
  transition: max-height 0.25s ease;
}
.faq-item.open .faq-a { max-height: 400px; }
.faq-a-inner {
  padding: 0 0 22px;
  font-size: 15.5px;
  line-height: 1.55;
  color: var(--ink-2);
}
.faq-a-inner > * + * { margin-top: 12px; }
.faq-a-inner p { margin: 0; }

/* Subscribe block (final CTA) */
.subscribe-block {
  max-width: 1280px; margin: 0 auto;
  padding: 80px 32px 80px;
}
.subscribe-card {
  background: #111;
  color: #f6f4ef;
  border-radius: 24px;
  padding: 56px 64px;
  display: grid;
  grid-template-columns: 1.4fr 1fr;
  gap: 48px;
  align-items: center;
}
.subscribe-card h3 {
  font-family: "Instrument Serif", serif;
  font-weight: 400;
  font-size: clamp(32px, 3.8vw, 48px);
  line-height: 1.05;
  letter-spacing: -0.02em;
  margin: 0 0 18px;
  text-wrap: balance;
}
.subscribe-card p {
  font-size: 16px;
  line-height: 1.55;
  color: rgba(246,244,239,0.65);
  margin: 0;
  max-width: 48ch;
}
.subscribe-actions {
  display: flex; flex-direction: column; gap: 12px;
}
.subscribe-actions button, .subscribe-actions a {
  appearance: none;
  display: inline-flex; align-items: center; justify-content: space-between; gap: 12px;
  padding: 16px 22px;
  border-radius: 12px;
  border: 0;
  font: inherit; font-weight: 500; font-size: 14.5px;
  cursor: pointer;
  text-decoration: none;
  text-align: left;
}
.subscribe-actions .sb-primary {
  background: var(--accent); color: white;
}
.subscribe-actions .sb-primary:hover { filter: brightness(0.94); }
.subscribe-actions .sb-secondary {
  background: rgba(246,244,239,0.07);
  color: #f6f4ef;
  border: 1px solid rgba(246,244,239,0.12);
}
.subscribe-actions .sb-secondary:hover { background: rgba(246,244,239,0.12); }

/* Related strip */
.lesson-related {
  max-width: 1280px; margin: 0 auto;
  padding: 0 32px;
}
.lesson-related-head {
  display: flex; align-items: baseline; justify-content: space-between;
  margin-bottom: 24px;
  padding-bottom: 18px;
  border-bottom: 1px solid var(--rule);
}
.lesson-related-h {
  font-family: "Instrument Serif", serif;
  font-weight: 400;
  font-size: clamp(28px, 3vw, 36px);
  letter-spacing: -0.02em;
  margin: 0;
}
.lesson-related-link {
  font-size: 13.5px;
  color: var(--ink-2);
  text-decoration: none;
}
.lesson-related-link:hover { color: var(--ink); }
.lesson-related-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 20px;
}

/* Responsive */
@media (max-width: 920px) {
  .lesson-layout {
    grid-template-columns: 1fr;
    gap: 0;
    padding: 16px 24px 64px;
  }
  .lesson-toc { display: none; }
  .lesson-header { padding: 48px 24px 28px; }
  .lesson-byline { flex-wrap: wrap; }
  .byline-tags { margin-left: 0; }
  .subscribe-block { padding: 56px 24px; }
  .subscribe-card { grid-template-columns: 1fr; padding: 36px 28px; gap: 28px; }
  .lesson-related { padding: 0 24px; }
}
@media (max-width: 560px) {
  .step { grid-template-columns: 40px 1fr; gap: 16px; padding: 22px 0; }
  .step-num { font-size: 32px; }
  .example-row { grid-template-columns: 80px 1fr; }
  .video-player-title { font-size: 18px; }
  .video-player-play { width: 56px; height: 56px; }
  .video-player-play::after {
    border-left-width: 14px;
    border-top-width: 8px; border-bottom-width: 8px;
  }
  .lesson-nav { padding: 12px 18px; }
  .lesson-nav-right { gap: 12px; }
  .lesson-nav-progress { width: 60px; }
}