/* ===========================================================
   Lesson page layout
   =========================================================== */
.lesson-shell { padding: 1rem 0 4rem; }

.lesson-grid {
  display: grid;
  grid-template-columns: 240px minmax(0, 1fr) 280px;
  gap: 2.5rem;
  align-items: start;
}
@media (max-width: 1100px) {
  .lesson-grid { grid-template-columns: minmax(0, 1fr) 260px; }
}
@media (max-width: 820px) {
  .lesson-grid { grid-template-columns: minmax(0, 1fr); }
  .lesson-actions { display: none; }
}

/* Rails stretch the full height of the lesson so their sticky panels stay in view */
.lesson-toc, .lesson-actions { align-self: stretch; }
.lesson-toc-inner, .lesson-actions-inner {
  position: sticky; top: calc(var(--nav-h) + 16px);
}

/* ---------- Navigator (left rail) ---------- */
.lesson-toc-inner {
  padding: .5rem .5rem .75rem;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--r-lg);
  box-shadow: var(--shadow-sm);
  max-height: calc(100vh - var(--nav-h) - 32px);
  overflow-y: auto;
  overscroll-behavior: contain;
  scrollbar-width: thin;
}
.nav-progress { height: 3px; margin: .25rem .5rem .5rem; background: var(--line); border-radius: 3px; overflow: hidden; }
.nav-progress span { display: block; height: 100%; width: 0; background: var(--gold); transition: width .15s linear; }
.nav-block + .nav-block { border-top: 1px solid var(--line); margin-top: .35rem; padding-top: .35rem; }
.nav-h {
  width: 100%; display: flex; align-items: center; justify-content: space-between; gap: .5rem;
  background: none; border: 0; cursor: pointer; font: inherit;
  padding: .55rem .6rem; border-radius: var(--r-sm);
  font-size: .7rem; font-weight: 700; letter-spacing: .09em; text-transform: uppercase; color: var(--text-muted);
  text-align: left;
}
.nav-h:hover { background: var(--surface-2); color: var(--text-dark); }
.nav-h svg { flex: none; transition: transform .2s; }
.nav-block:not(.open) .nav-h svg { transform: rotate(-90deg); }
.nav-block:not(.open) > ol, .nav-block:not(.open) > .nav-tools { display: none; }
.lesson-toc ol { list-style: none; padding: 0; margin: 0; }
.nav-lessons a {
  display: grid; grid-template-columns: 2.2rem 1fr auto; align-items: baseline; gap: .25rem;
  padding: .38rem .6rem; border-radius: var(--r-sm);
  font-size: .8rem; line-height: 1.35; color: var(--text-soft); text-decoration: none;
}
.nav-lessons a:hover { background: var(--surface-2); color: var(--text-dark); }
.nav-lessons a.current { background: var(--tint); color: var(--blue-primary); font-weight: 600; }
.nav-lessons .nl-num { font-variant-numeric: tabular-nums; color: var(--text-muted); font-size: .74rem; }
.nav-lessons .nl-state { color: var(--text-muted); align-self: center; }
.nav-lessons a.done .nl-state { color: var(--green); }
.nav-toc > li { margin: 0; }
.nav-row { display: flex; align-items: center; }
.nav-row a, .nav-sub a {
  flex: 1; display: block; padding: .38rem .6rem; border-radius: var(--r-sm);
  font-size: .82rem; line-height: 1.4; color: var(--text-soft); text-decoration: none;
  border-left: 2px solid transparent;
}
.nav-row a:hover, .nav-sub a:hover { background: var(--surface-2); color: var(--text-dark); }
.nav-row a.active { color: var(--blue-primary); font-weight: 600; border-left-color: var(--blue-mid); background: var(--tint); }
.nav-row a.is-folded { color: var(--text-muted); }
.nav-row a.is-folded::after { content: ' ·'; }
.sub-toggle {
  flex: none; width: 26px; height: 26px; display: grid; place-items: center;
  background: none; border: 0; border-radius: 6px; color: var(--text-muted); cursor: pointer;
}
.sub-toggle:hover { background: var(--surface-2); color: var(--text-dark); }
.sub-toggle svg { transform: rotate(-90deg); transition: transform .2s; }
.nav-toc li.sub-open .sub-toggle svg { transform: none; }
.nav-sub { display: none; margin: 0 0 .25rem .6rem !important; padding-left: .25rem !important; border-left: 1px solid var(--line); }
.nav-toc li.sub-open .nav-sub { display: block; }
.nav-sub a { font-size: .78rem; padding: .3rem .6rem; }
.nav-sub a.active { color: var(--blue-primary); font-weight: 600; }
.nav-tools { display: flex; flex-wrap: wrap; gap: .4rem; padding: .6rem .6rem .1rem; }
.nav-tools button {
  flex: 1; font: inherit; font-size: .74rem; font-weight: 600; cursor: pointer;
  padding: .4rem .5rem; border-radius: var(--r-sm);
  background: var(--surface-2); color: var(--text-soft); border: 1px solid var(--line);
}
.nav-tools button:hover { color: var(--blue-primary); border-color: var(--blue-mid); }

/* Small screens: the navigator becomes a drawer opened from a floating button */
.toc-fab, .toc-backdrop { display: none; }
@media (max-width: 1100px) {
  .lesson-toc {
    position: fixed; top: 0; left: 0; bottom: 0; z-index: 1200;
    width: min(86vw, 340px); padding: 1rem .75rem;
    background: var(--bg); box-shadow: var(--shadow-lg);
    transform: translateX(-105%); transition: transform .25s var(--ease, ease);
    align-self: auto;
  }
  .lesson-toc.open { transform: none; }
  .lesson-toc-inner { position: static; max-height: calc(100vh - 2rem); box-shadow: none; }
  .toc-fab {
    display: inline-flex; align-items: center; gap: .45rem;
    position: fixed; left: 16px; bottom: 18px; z-index: 1100;
    padding: .65rem 1rem; border-radius: 999px; border: 1px solid var(--line);
    background: var(--surface); color: var(--text-dark); font: inherit; font-size: .85rem; font-weight: 600;
    box-shadow: var(--shadow-lg); cursor: pointer;
  }
  .toc-backdrop { display: block; position: fixed; inset: 0; z-index: 1150; background: rgba(15,31,77,.35); opacity: 0; pointer-events: none; transition: opacity .2s; }
  .toc-backdrop.open { opacity: 1; pointer-events: auto; }
}

/* ---------- Collapsible lesson sections ---------- */
.lsec { border-top: 1px solid var(--line); margin-top: 2rem; padding: .75rem 0 0; }
.lsec:not(.folded) .lsec-body { padding-bottom: .25rem; }
.lsec:first-of-type { border-top: 0; margin-top: 0; padding-top: 0; }
.lsec-head { display: flex; align-items: center; gap: .5rem; }
.lsec-head h2 { flex: 1; margin: .5rem 0 !important; padding: 0 !important; border: 0 !important; cursor: pointer; }
.lsec-toggle {
  flex: none; width: 34px; height: 34px; display: grid; place-items: center;
  border-radius: 10px; border: 1px solid var(--line); background: var(--surface); color: var(--text-muted); cursor: pointer;
  transition: transform .2s, color .15s, border-color .15s;
}
.lsec-toggle:hover { color: var(--blue-primary); border-color: var(--blue-mid); }
.lsec.folded .lsec-toggle { transform: rotate(-90deg); }
.lsec.folded .lsec-body { display: none; }
.lsec.folded .lsec-head h2 { color: var(--text-soft); }
.lsec .mini-quiz-mount { margin-top: 1rem; }

/* Lesson hero (title row) */
.lesson-hero {
  margin-bottom: 2rem;
}
.lesson-hero .eyebrow { margin-bottom: .75rem; }
.lesson-hero h1 { margin: 0; }
.lesson-meta-row {
  display: flex; flex-wrap: wrap; gap: 1rem;
  margin-top: 1.25rem;
  color: var(--text-muted); font-size: .9rem;
}
.lesson-meta-row span {
  display: inline-flex; align-items: center; gap: .35rem;
}

/* Right rail meta card */
.lesson-meta-card {
  padding: 1.25rem;
  background: var(--bg-base);
  border-radius: var(--r-lg);
  box-shadow: var(--shadow-md);
  margin-bottom: 1rem;
}
.lesson-meta-card h4 {
  font-size: .72rem; font-weight: 700;
  letter-spacing: .1em; text-transform: uppercase;
  color: var(--text-muted); margin: 0 0 .65rem;
}
.lesson-meta-card .stat-line { gap: .75rem;
  display: flex; justify-content: space-between;
  padding: .4rem 0;
  font-size: .88rem;
  border-bottom: 1px solid var(--bg-soft);
}
.lesson-meta-card .stat-line:last-child { border-bottom: 0; }
.lesson-meta-card .stat-line strong { color: var(--text-dark); }
.lesson-mark-complete {
  margin-top: 1rem;
  width: 100%; justify-content: center;
}

/* Article body refinements (lesson-specific) */
.article-body h2 {
  scroll-margin-top: 80px;
  margin-top: 2.5rem;
  padding-top: 1rem;
  border-top: 1px solid var(--bg-soft);
}
.article-body h2:first-child { border-top: 0; padding-top: 0; margin-top: 0; }
.article-body h3 { margin-top: 1.75rem; }

.article-body blockquote {
  position: relative;
  margin: 1.5rem 0;
  padding: 1.25rem 1.5rem 1.25rem 2rem;
  background: var(--bg-base);
  border-radius: var(--r-md);
  box-shadow: var(--shadow-inset-sm);
  font-style: normal;
  color: var(--text-dark);
  border-left: 3px solid var(--blue-mid);
}
.article-body blockquote::before {
  content: '"';
  position: absolute;
  left: .5rem; top: .25rem;
  font-size: 2rem; font-weight: 800;
  color: var(--blue-soft);
  font-family: 'Inter', system-ui, sans-serif;
  line-height: 1;
  opacity: .6;
}

.article-body table { font-size: .92rem; }
.article-body table th { background: var(--bg-soft); }

/* Inline mini-quiz block, rendered when an h2 contains "mini-quiz" */
.mini-quiz-mount {
  margin: 2.5rem 0;
  padding: 1.75rem;
  background: var(--bg-base);
  border-radius: var(--r-xl);
  box-shadow: var(--shadow-md);
}
.mini-quiz-mount .mq-head {
  display: flex; align-items: flex-start; gap: 1rem;
  margin-bottom: 1.5rem;
}
.mini-quiz-mount .mq-icon {
  font-size: 1.75rem; line-height: 1;
  flex-shrink: 0;
  width: 48px; height: 48px;
  display: grid; place-items: center;
  border-radius: 999px;
  background: var(--bg-base);
  box-shadow: var(--shadow-inset);
}
.mini-quiz-mount h3 {
  font-size: 1.2rem;
  color: var(--blue-primary);
  margin: 0;
}

.mq-list {
  list-style: none; padding: 0; margin: 0;
  display: flex; flex-direction: column; gap: .85rem;
}
.mq-item {
  background: var(--bg-base);
  border-radius: var(--r-md);
  box-shadow: var(--shadow-inset-sm);
  padding: 1rem 1.1rem;
  transition: background 180ms;
}
.mq-item.mq-done {
  background: linear-gradient(0deg, rgba(16,185,129,.08), rgba(16,185,129,.08)), var(--bg-base);
}
.mq-q {
  display: flex; gap: .85rem; align-items: flex-start;
}
.mq-num {
  flex-shrink: 0;
  width: 30px; height: 30px;
  display: grid; place-items: center;
  border-radius: 999px;
  background: var(--bg-base);
  box-shadow: var(--shadow-sm);
  font-weight: 700; color: var(--blue-primary);
  font-size: .9rem;
  margin-top: 2px;
}
.mq-item.mq-done .mq-num {
  color: #fff;
  background: linear-gradient(145deg, #34D399, #10B981);
}
.mq-q-body { flex: 1; line-height: 1.55; color: var(--text-dark); font-size: .95rem; }
.mq-q-body strong { color: var(--text-dark); }

.mq-details {
  margin-top: .75rem; margin-left: 45px;
}
.mq-details summary {
  cursor: pointer;
  font-size: .85rem;
  color: var(--blue-mid);
  font-weight: 600;
  padding: .35rem 0;
  list-style: none;
  user-select: none;
}
.mq-details summary::-webkit-details-marker { display: none; }
.mq-details summary::before {
  content: '+';
  display: inline-block;
  width: 16px;
  font-weight: 700;
  color: var(--blue-mid);
  margin-right: .25rem;
}
.mq-details[open] summary::before { content: '−'; }

.mq-answer {
  width: 100%;
  margin-top: .65rem;
  padding: .75rem 1rem;
  background: var(--bg-base);
  border-radius: var(--r-sm);
  box-shadow: var(--shadow-inset-sm);
  font-family: inherit; font-size: .9rem;
  resize: vertical;
  min-height: 70px;
  border: 0; outline: 0;
  color: var(--text-dark);
}
.mq-answer:focus {
  box-shadow: var(--shadow-inset);
}
.mq-actions {
  display: flex; gap: .5rem;
  margin-top: .65rem;
}
.mq-hint {
  margin-top: .75rem;
  font-size: .82rem;
  color: var(--text-soft);
  padding-top: .75rem;
  border-top: 1px dashed var(--shadow-dark);
}
.mq-hint strong { color: var(--blue-primary); }

.mq-progress {
  display: flex; align-items: center; gap: 1rem;
  margin-top: 1.5rem;
  padding: .75rem 1rem;
  background: var(--bg-base);
  border-radius: 999px;
  box-shadow: var(--shadow-inset-sm);
}
.mq-progress-bar {
  flex: 1; height: 8px;
  background: var(--bg-base);
  box-shadow: var(--shadow-inset-sm);
  border-radius: 999px;
  overflow: hidden;
}
.mq-progress-bar span {
  display: block; height: 100%;
  background: linear-gradient(90deg, var(--blue-mid), var(--blue-soft));
  border-radius: 999px;
  transition: width 250ms;
}
.mq-progress-text {
  font-variant-numeric: tabular-nums;
  font-size: .82rem;
  color: var(--text-muted);
  font-weight: 600;
}
.mq-premium {
  margin-top: 1.25rem;
  padding: 1rem 1.25rem;
  background: var(--tint-gold);
  border-radius: var(--r-md);
  box-shadow: none;
  border-left: 3px solid var(--gold);
  font-size: .9rem;
}
.mq-premium strong { color: var(--blue-primary); }

/* Premium ribbon on lesson cards in unit indexes */
.lesson-card {
  display: flex; gap: 1rem;
  padding: 1.1rem 1.25rem;
  background: var(--bg-base);
  border-radius: var(--r-md);
  box-shadow: var(--shadow-sm);
  margin-bottom: .75rem;
  align-items: center;
  text-decoration: none;
  color: inherit;
  transition: all 180ms;
}
.lesson-card:hover { box-shadow: var(--shadow-pressed); }
.lesson-card .num {
  width: 36px; height: 36px;
  border-radius: 999px;
  display: grid; place-items: center;
  background: var(--bg-base);
  box-shadow: var(--shadow-inset-sm);
  font-weight: 700; color: var(--blue-primary);
  font-size: .9rem; flex-shrink: 0;
}
.lesson-card .body { flex: 1; min-width: 0; }
.lesson-card .body .t { font-weight: 600; color: var(--text-dark); }
.lesson-card .body .s { font-size: .85rem; color: var(--text-muted); margin-top: .2rem; }
.lesson-card .ribbon {
  display: inline-flex; padding: .25rem .65rem;
  border-radius: 999px;
  background: var(--bg-base);
  box-shadow: var(--shadow-inset-sm);
  font-size: .68rem; font-weight: 700;
  letter-spacing: .08em; text-transform: uppercase;
  color: var(--text-muted);
}
.lesson-card .ribbon.free { color: var(--green); }
.lesson-card .ribbon.premium { color: var(--gold); }
.lesson-card .ribbon.hl { color: var(--blue-mid); }

.next-prev {
  display: flex; justify-content: space-between;
  gap: 1rem; margin-top: 3rem;
}
.next-prev a {
  flex: 1; max-width: 280px;
  padding: 1rem 1.25rem;
  background: var(--bg-base);
  border-radius: var(--r-md);
  box-shadow: var(--shadow-sm);
  transition: all 180ms;
}
.next-prev a:hover { box-shadow: var(--shadow-pressed); }
.next-prev .label {
  font-size: .72rem; font-weight: 700;
  letter-spacing: .1em; text-transform: uppercase;
  color: var(--text-muted); margin-bottom: .25rem;
}
.next-prev .title {
  font-weight: 600; color: var(--text-dark);
}
.next-prev .right { text-align: right; }

/* Mark complete card */
.complete-card {
  margin: 2.5rem 0 0;
  padding: 1.5rem;
  background: var(--bg-base);
  border-radius: var(--r-md);
  box-shadow: var(--shadow-inset-sm);
  display: flex; gap: 1rem; align-items: center;
}
.complete-card .icon-circle-sm {
  flex-shrink: 0;
  background: var(--bg-base);
  box-shadow: var(--shadow-sm);
  color: var(--blue-primary);
}
.complete-card.done .icon-circle-sm { color: var(--green); }
.complete-card .body { flex: 1; }
.complete-card .body strong { color: var(--text-dark); }
.complete-card .body p { margin: .25rem 0 0; font-size: .9rem; color: var(--text-soft); }

/* Translation banner shown when Spanish version is unavailable */
.translation-notice {
  padding: 1rem 1.25rem;
  background: var(--bg-base);
  border-radius: var(--r-md);
  box-shadow: var(--shadow-inset-sm);
  border-left: 3px solid var(--gold);
  font-size: .9rem;
  margin-bottom: 1.5rem;
}

/* ===========================================================
   Polished article styling for the markdown renderer
   =========================================================== */

/* Hero-style opening blockquote — first quote in lesson body */
.article-body > blockquote.hero-quote,
.article-body > blockquote:first-of-type {
  margin: 0 0 2.5rem;
  padding: 2rem 2.25rem 2rem 3rem;
  background: linear-gradient(135deg, var(--bg-base), var(--bg-soft));
  border-radius: var(--r-xl);
  box-shadow: var(--shadow-lg);
  border-left: 0;
  font-size: 1.05rem;
  font-style: normal;
  line-height: 1.7;
  position: relative;
  color: var(--text-dark);
}
.article-body > blockquote.hero-quote::before,
.article-body > blockquote:first-of-type::before {
  content: '“';
  position: absolute;
  left: 1.1rem; top: .25rem;
  font-size: 4rem; font-weight: 800;
  color: var(--blue-mid);
  font-family: 'Inter', system-ui, sans-serif;
  line-height: 1;
  opacity: .5;
}
.article-body > blockquote.hero-quote p,
.article-body > blockquote:first-of-type p {
  margin: 0; color: var(--text-dark);
}
.article-body > blockquote.hero-quote em,
.article-body > blockquote:first-of-type em { font-style: italic; }

/* Standard callout-style blockquotes (the IB Tip / 💡 / 🎯 blocks) */
.article-body blockquote:not(.hero-quote):not(:first-of-type) {
  margin: 1.5rem 0;
  padding: 1rem 1.25rem 1rem 1.5rem;
  background: var(--bg-base);
  border-radius: var(--r-md);
  box-shadow: var(--shadow-inset-sm);
  border-left: 3px solid var(--blue-mid);
  font-style: normal;
  color: var(--text-dark);
  font-size: .95rem;
}
.article-body blockquote:not(.hero-quote):not(:first-of-type)::before {
  content: none;
}
.article-body blockquote:not(.hero-quote):not(:first-of-type) p {
  margin: 0;
}
.article-body blockquote:not(.hero-quote):not(:first-of-type) p + p {
  margin-top: .65rem;
}

/* Tables — better defaults */
.article-body .md-table-wrap {
  margin: 1.75rem 0;
  border-radius: var(--r-md);
  box-shadow: var(--shadow-sm);
  background: var(--bg-base);
  overflow-x: auto;
}
.article-body table {
  width: 100%;
  border-collapse: separate;
  border-spacing: 0;
  font-size: .92rem;
}
.article-body th {
  background: var(--bg-soft);
  color: var(--text-dark);
  font-weight: 700;
  font-size: .78rem;
  text-transform: uppercase;
  letter-spacing: .06em;
  padding: .85rem 1rem;
  text-align: left;
  border-bottom: 1px solid var(--bg-softer);
}
.article-body td {
  padding: .75rem 1rem;
  vertical-align: top;
  color: var(--text-soft);
}
.article-body tr + tr td { border-top: 1px solid var(--bg-soft); }
.article-body tr:hover td { background: var(--bg-soft); }
.article-body td strong { color: var(--text-dark); }

/* ASCII / pre code blocks — show them cleanly so the diagrams in the markdown
   render in monospace and don't look like leaked symbols */
.article-body pre.code-block {
  margin: 1.5rem 0;
  padding: 1.25rem 1.5rem;
  background: var(--bg-base);
  border-radius: var(--r-md);
  box-shadow: var(--shadow-inset-sm);
  overflow-x: auto;
  font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  font-size: .82rem;
  line-height: 1.55;
  color: var(--text-dark);
}
.article-body pre.code-block code {
  background: transparent;
  box-shadow: none;
  padding: 0;
  color: inherit;
  font-size: inherit;
  white-space: pre;
}

/* Inline code — softer */
.article-body code {
  font-family: inherit;
  font-weight: 600;
  font-size: .95em;
  font-variant-numeric: tabular-nums;
  padding: .1em .45em;
  background: var(--tint);
  box-shadow: none;
  border-radius: 6px;
  color: var(--blue-primary);
}

/* H3/H4 visual hierarchy — keep the document scannable */
.article-body h3 {
  font-size: 1.2rem;
  color: var(--text-dark);
  margin-top: 1.75rem;
}
.article-body h4 {
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--blue-primary);
  margin-top: 1.5rem;
  margin-bottom: .5rem;
  padding-left: .75rem;
  border-left: 3px solid var(--blue-primary);
  line-height: 1.35;
}

/* Inline diagrams (replaces ASCII art) — bilingual SVG via diagrams.js */
.lesson-diagram {
  margin: 1.5rem 0 2rem;
  padding: 1.25rem;
  background: var(--bg-base);
  border-radius: var(--r-xl);
  box-shadow: var(--shadow-md);
  text-align: center;
}
.lesson-diagram svg {
  max-width: 100%;
  height: auto;
  display: block;
  margin: 0 auto;
}

/* BMT reference diagram */
.bmt-diagram {
  margin: 1rem 0 2rem;
  padding: 1.5rem;
  background: var(--bg-base);
  border-radius: var(--r-xl);
  box-shadow: var(--shadow-md);
  text-align: center;
}
.bmt-diagram svg { max-width: 100%; height: auto; }
.bmt-diagram figcaption {
  margin-top: 1rem;
  font-size: .82rem;
  color: var(--text-muted);
  font-weight: 600;
  letter-spacing: .08em;
  text-transform: uppercase;
}

/* ===========================================================
   Callout boxes (replace emoji-led blockquotes)
   =========================================================== */
.article-body .callout-box {
  --co: var(--blue-mid); --co-bg: var(--tint);
  margin: 1.5rem 0; padding: .9rem 1.15rem 1rem;
  border-radius: var(--r-md); background: var(--surface);
  border: 1px solid var(--line); border-left: 3px solid var(--co);
  font-size: .95rem; color: var(--text-dark);
}
.callout-box .co-head {
  display: flex; align-items: center; gap: .45rem; margin-bottom: .35rem;
  font-size: .72rem; font-weight: 700; letter-spacing: .08em; text-transform: uppercase; color: var(--co);
}
.callout-box .co-ico { width: 16px; height: 16px; flex: none; }
.callout-box .co-body p { margin: 0; }
.callout-box .co-body p + p, .callout-box .co-body ul, .callout-box .co-body ol { margin-top: .55rem; }
.callout-box.co-exam    { --co: #B45309; }
.callout-box.co-warning { --co: var(--red); }
.callout-box.co-case    { --co: var(--blue-primary); }
.callout-box.co-check   { --co: var(--green); }
.callout-box.co-key, .callout-box.co-formula { --co: #7C3AED; }
.callout-box.co-data, .callout-box.co-context { --co: #0E7490; }
[data-theme="dark"] .callout-box.co-exam { --co: var(--gold); }
[data-theme="dark"] .callout-box.co-key, [data-theme="dark"] .callout-box.co-formula { --co: #A78BFA; }
[data-theme="dark"] .callout-box.co-data, [data-theme="dark"] .callout-box.co-context { --co: #22D3EE; }

/* Marks that replace ✅ ❌ 🟢 🔴 🟡 */
.mk { display: inline-block; width: .95em; height: .95em; margin-right: .4em; vertical-align: -.12em; border-radius: 50%; flex: none; }
.mk-ok { background: var(--green); -webkit-mask: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24'%3E%3Cpath d='M9 16.2 4.8 12l-1.4 1.4L9 19 21 7l-1.4-1.4z'/%3E%3C/svg%3E") center/100% no-repeat; mask: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24'%3E%3Cpath d='M9 16.2 4.8 12l-1.4 1.4L9 19 21 7l-1.4-1.4z'/%3E%3C/svg%3E") center/100% no-repeat; border-radius: 0; }
.mk-no { background: var(--red); -webkit-mask: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24'%3E%3Cpath d='M19 6.4 17.6 5 12 10.6 6.4 5 5 6.4 10.6 12 5 17.6 6.4 19l5.6-5.6 5.6 5.6 1.4-1.4-5.6-5.6z'/%3E%3C/svg%3E") center/100% no-repeat; mask: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24'%3E%3Cpath d='M19 6.4 17.6 5 12 10.6 6.4 5 5 6.4 10.6 12 5 17.6 6.4 19l5.6-5.6 5.6 5.6 1.4-1.4-5.6-5.6z'/%3E%3C/svg%3E") center/100% no-repeat; border-radius: 0; }
.mk-plus { width: .55em; height: .55em; background: var(--green); vertical-align: .05em; }
.mk-minus { width: .55em; height: .55em; background: var(--red); vertical-align: .05em; }
.mk-mid { width: .55em; height: .55em; background: var(--gold); vertical-align: .05em; }

/* Plain quotes inside sections (examples, good/bad comparisons) */
.lsec-body blockquote {
  margin: 1.25rem 0; padding: .85rem 1.15rem; background: var(--surface-2);
  border: 0; border-left: 3px solid var(--line); border-radius: var(--r-sm);
  box-shadow: none; font-size: .95rem; color: var(--text-dark);
}
.lsec-body blockquote::before { content: none !important; }
.lsec-body blockquote p { margin: 0; }
.lsec-body blockquote p + p { margin-top: .5rem; }

/* ---------- No boxes in lesson text (Oct 2026): quotes are plain, light rule ---------- */
#lesson-body blockquote,
#lesson-body .lsec-body blockquote,
.article-body > blockquote:first-of-type,
.article-body blockquote:not(.hero-quote):not(:first-of-type) {
  background: none !important; box-shadow: none !important; border-radius: 0 !important;
  border: 0 !important; border-left: 2px solid var(--line) !important;
  padding: .1rem 0 .1rem 1rem !important; margin: 1.25rem 0 !important;
  font-size: inherit !important; color: var(--text-mid, var(--text-dark)) !important;
}
#lesson-body blockquote::before, .article-body blockquote::before { content: none !important; }
#lesson-body h4 { font-size: 1rem; font-weight: 700; margin: 1.5rem 0 .4rem; color: var(--text-dark); letter-spacing: 0; text-transform: none; }
#lesson-body h4 { border: 0 !important; padding-left: 0 !important; }
#lesson-body h4::before { content: none !important; }

/* ---------- Study notes (tips, examiner's view, real cases…): no boxes, no emojis ----------
   A quiet labelled line with a thin rule; opens on hover (mouse) or tap (touch). */
#lesson-body details.note { --note: #2563EB; margin: 1rem 0; padding: .15rem 0 .15rem .9rem; border-left: 2px solid color-mix(in srgb, var(--note) 45%, transparent); }
#lesson-body details.note-tip      { --note: #2563EB; }
#lesson-body details.note-exam     { --note: #B45309; }
#lesson-body details.note-case     { --note: #0F766E; }
#lesson-body details.note-warning,
#lesson-body details.note-mistake  { --note: #B91C1C; }
#lesson-body details.note-remember { --note: #6D28D9; }
#lesson-body details.note-context  { --note: #475569; }
[data-theme="dark"] #lesson-body details.note-tip      { --note: #93C5FD; }
[data-theme="dark"] #lesson-body details.note-exam     { --note: #FBBF24; }
[data-theme="dark"] #lesson-body details.note-case     { --note: #5EEAD4; }
[data-theme="dark"] #lesson-body details.note-warning,
[data-theme="dark"] #lesson-body details.note-mistake  { --note: #FCA5A5; }
[data-theme="dark"] #lesson-body details.note-remember { --note: #C4B5FD; }
[data-theme="dark"] #lesson-body details.note-context  { --note: #CBD5E1; }
#lesson-body details.note > summary {
  list-style: none; cursor: pointer; display: flex; align-items: baseline; gap: .65rem;
  font-size: .93rem; line-height: 1.5; color: var(--text-muted); padding: .2rem 0; user-select: none;
}
#lesson-body details.note > summary::-webkit-details-marker { display: none; }
#lesson-body details.note > summary:focus-visible { outline: 2px solid var(--note); outline-offset: 3px; border-radius: 4px; }
#lesson-body .note-kind { flex: none; font-size: .7rem; font-weight: 700; letter-spacing: .07em; text-transform: uppercase; color: var(--note); }
#lesson-body .note-title { flex: 1 1 auto; min-width: 0; font-weight: 600; color: var(--text-dark); }
#lesson-body .note-teaser { flex: 1 1 auto; min-width: 0; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
#lesson-body .note-chev { flex: none; width: 14px; height: 14px; align-self: center; color: var(--text-muted); transition: transform .18s ease; }
#lesson-body details.note > summary:hover .note-teaser,
#lesson-body details.note > summary:hover .note-chev { color: var(--text-dark); }
#lesson-body details.note[open] .note-chev { transform: rotate(90deg); }
#lesson-body details.note[open] .note-teaser { visibility: hidden; }
#lesson-body details.note .note-body { padding: .2rem 0 .3rem; color: var(--text-dark); }
#lesson-body details.note .note-body > :first-child { margin-top: 0; }
#lesson-body details.note .note-body > :last-child { margin-bottom: 0; }
#lesson-body details.note .note-body p { margin: .45rem 0; }
.nav-tools .notes-toggle { display: flex; align-items: center; gap: .45rem; flex-basis: 100%; margin-top: .35rem; font-size: .8rem; color: var(--text-muted); cursor: pointer; }
.nav-tools .notes-toggle input { accent-color: var(--blue-mid); }
@media print { #lesson-body details.note .note-body { display: block !important; } }
.lesson-grid > *, .lesson-content { min-width: 0; }
.lesson-grid > .lesson-content { width: 100%; }
#lesson-body details.note > summary { contain: inline-size; }

/* ---------- Figures (js/figures.js): two inks + gold, light/dark via tokens ---------- */
.lesson-figure {
  --f-ink: #0F1F4D; --f-blue: #2563EB; --f-gold: #D97706; --f-pos: #047857; --f-neg: #B91C1C; --f-muted: #64748B;
  --f-grid: rgba(15,31,77,.14); --f-paper: #FFFFFF;
  --f-ink-soft: rgba(15,31,77,.10); --f-blue-soft: rgba(37,99,235,.13); --f-gold-soft: rgba(251,191,36,.38);
  --f-pos-soft: rgba(16,185,129,.16); --f-neg-soft: rgba(239,68,68,.13); --f-muted-soft: rgba(100,116,139,.14); --f-grid-soft: rgba(15,31,77,.06);
  margin: 1.6rem 0 2rem; padding: 0; background: none; box-shadow: none; text-align: left;
}
[data-theme="dark"] .lesson-figure {
  --f-ink: #E6EDF7; --f-blue: #8AB4FF; --f-gold: #FBBF24; --f-pos: #4ADE80; --f-neg: #F87171; --f-muted: #A3B1C6;
  --f-grid: rgba(230,237,247,.14); --f-paper: #0F1A33;
  --f-ink-soft: rgba(230,237,247,.10); --f-blue-soft: rgba(138,180,255,.16); --f-gold-soft: rgba(251,191,36,.28);
  --f-pos-soft: rgba(74,222,128,.16); --f-neg-soft: rgba(248,113,113,.16); --f-muted-soft: rgba(163,177,198,.14); --f-grid-soft: rgba(230,237,247,.06);
}
.lesson-figure svg { width: 100%; height: auto; display: block; font-family: 'Inter', system-ui, sans-serif; font-variant-numeric: tabular-nums; overflow: visible; }
.lesson-figure figcaption { margin-top: .6rem; font-size: .86rem; line-height: 1.45; color: var(--text-muted); }
.lesson-figure figcaption b { color: var(--text-dark); font-weight: 600; }
.lesson-figure figcaption .f-src { display: block; font-size: .78rem; margin-top: .15rem; }