/* Lesson 03 · The Dragon's Power
   Reading system lives in ../lesson-reading.css.
   Only lesson-specific pieces belong here. */

/* --- the 100-scrolls / 10-slots model -------------------------- */

.vault-model {
  padding: 1.4rem;
  border: 1px solid var(--line);
  border-radius: 14px;
  background: var(--panel);
}

.vault-model > p:first-child {
  margin: 0 0 1rem;
  color: var(--jade);
  font: 800 0.67rem/1 var(--mono);
  letter-spacing: 0.1em;
  text-transform: uppercase;
}

.model-row {
  display: grid;
  gap: 0.25rem;
  padding: 1rem;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--bg-soft);
}

.model-row span,
.model-row small {
  color: var(--faint);
  font: 700 0.6rem/1 var(--mono);
  letter-spacing: 0.06em;
  text-transform: uppercase;
}

.model-row strong {
  font-family: var(--serif);
  font-size: 1.6rem;
  line-height: 1.15;
}

.model-row:not(.model-disk) {
  border-color: color-mix(in srgb, var(--jade) 50%, var(--line));
}

.model-disk {
  border-color: color-mix(in srgb, var(--moss) 45%, var(--line));
  background: color-mix(in srgb, var(--moss) 7%, transparent);
}

.model-divider {
  height: 1.6rem;
  color: var(--faint);
  font-style: normal;
  line-height: 1.6rem;
  text-align: center;
}

.vault-model .model-note {
  margin: 1rem 0 0;
  color: var(--muted);
  font-size: 0.85rem;
  line-height: 1.5;
}

/* --- static marginal diagrams -------------------------------- */

.reading-side-layout,
.subsection-side-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(270px, 340px);
  gap: clamp(2.25rem, 6vw, 4.5rem);
  align-items: start;
}

.reading-side-layout {
  margin-top: 0.25rem;
}

.subsection-side-layout {
  margin-top: 3rem;
}

.side-copy > p,
.subsection-copy > p,
.subsection-copy > ul {
  max-width: 780px;
  margin: 0 0 1.3rem;
  color: var(--muted);
  font-size: clamp(1.05rem, 1.8vw, 1.2rem);
  line-height: 1.85;
}

.subsection-copy > ul {
  padding-left: 1.4rem;
}

.side-copy > p:last-child,
.subsection-copy > p:last-child,
.subsection-copy > ul:last-child {
  margin-bottom: 0;
}

.side-copy h3,
.subsection-copy h3 {
  margin-top: 0;
}

.lesson-side-visual {
  position: relative;
  width: 100%;
  margin: 0;
  padding: 1.3rem;
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: 12px;
  background:
    linear-gradient(145deg, color-mix(in srgb, var(--jade) 4%, transparent), transparent 62%),
    var(--panel);
  box-shadow: inset 0 1px 0 color-mix(in srgb, var(--jade) 10%, transparent);
}

.lesson-side-visual figcaption {
  margin-bottom: 1.25rem;
  color: var(--jade);
  font: 800 0.78rem/1.35 var(--mono);
  letter-spacing: 0.09em;
  text-transform: uppercase;
}

.lesson-side-visual small {
  color: var(--faint);
  font: 800 0.64rem/1.35 var(--mono);
  letter-spacing: 0.07em;
  text-transform: uppercase;
}

.lesson-side-visual > p {
  margin: 1.1rem 0 0;
  color: var(--muted);
  font-size: 0.9rem;
  line-height: 1.55;
}

.scan-page-row {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr)) auto minmax(0, 1fr);
  gap: 0.4rem;
  align-items: center;
}

.scan-page-row span {
  display: grid;
  min-height: 52px;
  place-items: center;
  border: 1px solid var(--line);
  border-radius: 7px;
  background: var(--bg-soft);
  color: var(--muted);
  font: 800 0.75rem/1 var(--mono);
}

.scan-page-row i {
  color: var(--faint);
  font-style: normal;
}

.scan-page-row .target-page {
  border-color: color-mix(in srgb, var(--moss) 55%, var(--line));
  background: color-mix(in srgb, var(--moss) 8%, var(--bg-soft));
  color: var(--moss);
}

.visual-verdict {
  display: grid;
  gap: 0.35rem;
  margin-top: 1rem;
  padding-top: 1rem;
  border-top: 1px solid var(--line);
}

.visual-verdict strong {
  color: var(--text);
  font-size: 1rem;
  line-height: 1.45;
}

.scan-cycle-visual {
  display: grid;
  gap: 0.65rem;
}

.cycle-step {
  display: grid;
  gap: 0.35rem;
  padding: 0.9rem;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--bg-soft);
}

.cycle-step strong {
  color: var(--text);
  font: 700 0.86rem/1.45 var(--mono);
}

.buffer-state {
  border-color: color-mix(in srgb, var(--jade) 38%, var(--line));
}

.restart-step {
  border-color: color-mix(in srgb, var(--moss) 48%, var(--line));
  background: color-mix(in srgb, var(--moss) 6%, var(--bg-soft));
}

.btree-visual {
  text-align: center;
}

.btree-visual figcaption,
.index-build-visual figcaption {
  text-align: left;
}

.tree-root {
  display: inline-grid;
  gap: 0.3rem;
  min-width: 142px;
  padding: 0.85rem 1rem;
  border: 1px solid color-mix(in srgb, var(--moss) 50%, var(--line));
  border-radius: 8px;
  background: color-mix(in srgb, var(--moss) 7%, var(--bg-soft));
}

.tree-root strong {
  color: var(--text);
  font-size: 0.95rem;
}

.tree-connector {
  position: relative;
  width: 78%;
  height: 34px;
  margin: 0 auto;
  border-right: 1px solid color-mix(in srgb, var(--jade) 42%, var(--line));
  border-bottom: 1px solid color-mix(in srgb, var(--jade) 42%, var(--line));
  border-left: 1px solid color-mix(in srgb, var(--jade) 42%, var(--line));
}

.tree-connector::before {
  position: absolute;
  top: 0;
  left: 50%;
  height: 100%;
  border-left: 1px solid color-mix(in srgb, var(--jade) 42%, var(--line));
  content: "";
}

.tree-leaves {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 0.35rem;
}

.tree-leaves span {
  padding: 0.65rem 0.25rem;
  border: 1px solid color-mix(in srgb, var(--jade) 38%, var(--line));
  border-radius: 6px;
  background: var(--bg-soft);
  color: var(--muted);
  font: 700 0.58rem/1.25 var(--mono);
}

.index-page-stack {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 0.4rem;
}

.index-page-stack span {
  padding: 0.7rem 0.3rem;
  border: 1px solid color-mix(in srgb, var(--jade) 38%, var(--line));
  border-radius: 6px;
  background: var(--bg-soft);
  color: var(--muted);
  font: 800 0.62rem/1.3 var(--mono);
  text-align: center;
  text-transform: uppercase;
}

.index-page-stack .root-page {
  grid-column: 1 / -1;
  justify-self: center;
  min-width: 120px;
  border-color: color-mix(in srgb, var(--moss) 50%, var(--line));
  background: color-mix(in srgb, var(--moss) 7%, var(--bg-soft));
  color: var(--text);
}

.lookup-route {
  display: grid;
  justify-items: stretch;
  gap: 0.35rem;
  margin-top: 1.2rem;
  padding-top: 1.2rem;
  border-top: 1px solid var(--line);
}

.lookup-route span {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 1rem;
}

.lookup-route strong {
  color: var(--text);
  font-size: 0.9rem;
}

.lookup-route i {
  color: var(--jade);
  font: 700 0.8rem/1 var(--mono);
  font-style: normal;
  text-align: center;
  transform: rotate(90deg);
}

@media (max-width: 780px) {
  .reading-side-layout,
  .subsection-side-layout {
    grid-template-columns: 1fr;
    gap: 2rem;
  }

  .lesson-side-visual {
    width: min(100%, 520px);
    margin-left: auto;
  }

  .subsection-side-layout {
    margin-top: 2.5rem;
  }
}