/* ──────────────────────────────────────────────────────────────────────────
   Learning Center — section-specific styles.
   Base design tokens come from ../shared/tokens.css; shared card/button
   aesthetics from ../games/shared/style.css. This file only adds what the
   capability-map / track-map / node-detail views need.
   ────────────────────────────────────────────────────────────────────────── */

html, body {
  min-height: 100dvh;
  background: var(--bg);
  color: var(--text);
  font-family: var(--font);
  -webkit-font-smoothing: antialiased;
  margin: 0;
}
body { display: flex; flex-direction: column; }

/* ── Hero ── */
.learn-hero {
  width: 100%;
  max-width: 1040px;
  margin: 0 auto;
  padding: 56px 24px 24px;
  box-sizing: border-box;
}
.learn-hero-top { display: flex; align-items: baseline; }
.brand-name {
  font-size: 28px; font-weight: 600; color: var(--accent);
  letter-spacing: -0.2px; line-height: 1; text-decoration: none;
}
.brand-name:hover { opacity: 0.85; }
.brand-sub,
.brand-sub:any-link {
  font-size: 12px; font-weight: 600; color: var(--text-3);
  text-transform: uppercase; letter-spacing: 0.8px; margin-left: 8px;
  text-decoration: none;
}
.brand-sub:hover,
.brand-sub:any-link:hover {
  color: var(--accent);
  text-decoration: none;
}
.brand-sub:visited { color: var(--text-3); }
.brand-sub:focus-visible {
  border-radius: 4px;
  outline: 2px solid color-mix(in srgb, var(--accent) 28%, white);
  outline-offset: 3px;
  text-decoration: none;
}
.learn-tagline {
  font-size: 19px; font-weight: 600; color: var(--text);
  margin: 22px 0 6px; line-height: 1.4;
}
.learn-subtagline { font-size: 14px; color: var(--text-2); margin: 0; line-height: 1.5; }

.learn-nav { display: flex; gap: 18px; margin-top: 14px; }
.learn-nav a {
  font-size: 13px; color: var(--text-2); text-decoration: none; font-weight: 500;
}
.learn-nav a:hover { color: var(--accent); }

.learn-progress-bar-wrap { margin-top: 20px; max-width: 420px; }
.learn-progress-bar {
  height: 8px; background: var(--bg-3); border-radius: 6px; overflow: hidden;
  border: 1px solid var(--border-subtle);
}
.learn-progress-fill {
  height: 100%; width: 0%; background: var(--accent);
  transition: width 0.4s ease;
}
.learn-progress-label {
  font-size: 12px; color: var(--text-3); margin-top: 6px;
  font-variant-numeric: tabular-nums;
}

/* ── Content / track map ── */
.learn-content {
  width: 100%; max-width: 1040px; margin: 0 auto; flex: 1;
  padding: 0 24px 48px; box-sizing: border-box;
}
.learn-home-panel {
  display: grid;
  gap: 14px;
  grid-template-columns: minmax(0, 720px);
  margin-bottom: 28px;
}
.learn-home-primary,
.learn-home-secondary {
  border: 1px solid var(--border);
  border-radius: 8px;
  box-sizing: border-box;
  color: var(--text);
  display: grid;
  gap: 8px;
  min-height: 132px;
  padding: 20px 22px;
  text-decoration: none;
}
.learn-home-primary {
  background: white;
}
.learn-home-primary:hover {
  border-color: var(--accent);
}
.learn-home-secondary {
  background: var(--bg-2);
}
.learn-home-kicker {
  color: var(--text-3);
  font-size: 11px;
  font-weight: 800;
  letter-spacing: 0.7px;
  text-transform: uppercase;
}
.learn-home-primary strong,
.learn-home-secondary strong {
  font-size: 20px;
  line-height: 1.25;
}
.learn-home-primary span:last-child,
.learn-home-secondary span:last-child {
  color: var(--text-2);
  font-size: 14px;
  line-height: 1.5;
}
.trackmap { display: flex; flex-direction: column; gap: 28px; }

.track {
  border: 1px solid var(--border);
  border-radius: 10px;
  background: var(--bg-2);
  overflow: hidden;
}
.track-header {
  display: flex; align-items: baseline; gap: 10px; flex-wrap: wrap;
  padding: 16px 18px 12px;
  border-bottom: 1px solid var(--border-subtle);
}
.track-title {
  font-size: 16px; font-weight: 700; color: var(--text);
}
.track-accent { color: var(--track-color, var(--accent)); }
.track-gateway-flag {
  font-size: 10px; font-weight: 700; text-transform: uppercase;
  letter-spacing: 0.6px; color: var(--bg); background: var(--track-color, var(--accent));
  padding: 2px 7px; border-radius: 999px;
}
.track-blurb { font-size: 13px; color: var(--text-2); line-height: 1.5; flex-basis: 100%; margin: 0; }
.track-progress {
  font-size: 12px; color: var(--text-3); margin-left: auto;
  font-variant-numeric: tabular-nums; white-space: nowrap;
}

.track-nodes {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
  gap: 10px;
  padding: 14px 18px 16px;
}

/* ── Node tile ── */
.node-tile {
  position: relative;
  display: flex; flex-direction: column; gap: 6px;
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 13px 14px;
  background: var(--bg-3);
  cursor: pointer;
  text-align: left;
  color: inherit;
  font-family: inherit;
  transition: border-color 0.12s, transform 0.08s;
}
.node-tile:hover { transform: translateY(-1px); }
.node-title { font-size: 14px; font-weight: 700; color: var(--text); line-height: 1.25; }
.node-desc { font-size: 12px; color: var(--text-2); line-height: 1.45; margin: 0; }
.node-status {
  font-size: 10px; font-weight: 700; text-transform: uppercase;
  letter-spacing: 0.6px;
}

/* states */
.node-tile.locked {
  opacity: 0.55; cursor: pointer; background: var(--bg-2);
  border-style: dashed;
}
.node-tile.locked .node-status { color: var(--text-3); }
.node-tile.available {
  border-color: var(--track-color, var(--accent));
  box-shadow: 0 0 0 1px var(--track-color, var(--accent)) inset;
}
.node-tile.available .node-status { color: var(--track-color, var(--accent)); }
.node-tile.mastered {
  background: color-mix(in srgb, var(--track-color, var(--accent)) 14%, var(--bg-3));
  border-color: var(--track-color, var(--accent));
}
.node-tile.mastered .node-status { color: var(--green); }
.node-tile.mastered .node-title::after { content: " ✓"; color: var(--green); }

.node-prereq-hint {
  font-size: 11px; color: var(--text-3); margin: 2px 0 0; line-height: 1.4;
}

/* ── Track milestone banner ── */
.track-milestone {
  margin: 0 18px 16px; padding: 11px 14px;
  border-radius: 8px; font-size: 13px; line-height: 1.5;
  border: 1px solid var(--green);
  background: color-mix(in srgb, var(--green) 12%, var(--bg-2));
  color: var(--text);
}
.track-milestone.hidden-milestone { display: none; }
.track-milestone strong { color: var(--green); }

/* ── Node detail overlay ── */
.node-overlay {
  position: fixed; inset: 0; z-index: 50;
  background: rgba(0,0,0,0.6);
  display: flex; align-items: flex-start; justify-content: center;
  overflow-y: auto; padding: 40px 16px;
}
.node-overlay[hidden] { display: none; }
.node-panel {
  position: relative;
  width: 100%; max-width: 640px;
  background: var(--bg-2);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 28px 26px 26px;
  box-shadow: 0 18px 50px rgba(0,0,0,0.5);
}
.node-close {
  position: absolute; top: 12px; right: 14px;
  background: none; border: none; color: var(--text-3);
  font-size: 26px; line-height: 1; cursor: pointer;
}
.node-close:hover { color: var(--text); }

.detail-track-tag {
  font-size: 11px; font-weight: 700; text-transform: uppercase;
  letter-spacing: 0.7px; color: var(--track-color, var(--accent));
}
.detail-title { font-size: 20px; font-weight: 700; margin: 6px 0 8px; }
.detail-desc { font-size: 14px; color: var(--text-2); line-height: 1.55; margin: 0 0 18px; }

.detail-section-title {
  font-size: 12px; font-weight: 700; text-transform: uppercase;
  letter-spacing: 0.7px; color: var(--text-3); margin: 20px 0 8px;
}

.objective-list { list-style: none; padding: 0; margin: 0; display: flex; flex-direction: column; gap: 7px; }
.objective-item { display: flex; gap: 9px; align-items: flex-start; font-size: 13px; line-height: 1.5; cursor: pointer; }
.objective-item input { margin-top: 2px; accent-color: var(--accent); width: 15px; height: 15px; flex-shrink: 0; }
.objective-item.checked span { color: var(--text-3); text-decoration: line-through; }

.derivation-list, .resource-list { padding-left: 18px; margin: 0; display: flex; flex-direction: column; gap: 6px; }
.derivation-list li, .resource-list li { font-size: 13px; color: var(--text-2); line-height: 1.5; }
.derivation-list li { color: var(--text); }

/* ── Mark-mastered control ── */
.detail-actions { margin-top: 24px; border-top: 1px solid var(--border-subtle); padding-top: 18px; }
.gate-note { font-size: 12px; color: var(--text-3); margin: 0 0 10px; line-height: 1.5; }
.gate-note.locked-note { color: var(--orange); }
.master-btn {
  font-family: inherit; font-size: 14px; font-weight: 600;
  padding: 10px 18px; border-radius: 8px; cursor: pointer;
  border: 1px solid var(--accent); background: var(--accent); color: #0b0d12;
  transition: opacity 0.12s;
}
.master-btn:hover { opacity: 0.9; }
.master-btn:disabled { opacity: 0.4; cursor: not-allowed; }
.master-btn.is-mastered { background: transparent; color: var(--green); border-color: var(--green); }

/* ── Reorder checkpoint ── */
.checkpoint {
  margin-top: 8px; border: 1px solid var(--border);
  border-radius: 8px; padding: 14px; background: var(--bg-3);
}
.checkpoint-prompt { font-size: 13px; color: var(--text-2); margin: 0 0 12px; line-height: 1.5; }
.checkpoint-steps { list-style: none; padding: 0; margin: 0; display: flex; flex-direction: column; gap: 8px; }
.checkpoint-step {
  display: flex; gap: 10px; align-items: flex-start;
  padding: 9px 11px; border-radius: 6px;
  border: 1px solid var(--border);
  background: var(--bg-2);
  font-size: 13px; line-height: 1.45;
  cursor: grab; user-select: none;
}
.checkpoint-step.dragging { opacity: 0.45; }
.checkpoint-step.drag-over { border-color: var(--accent); }
.checkpoint-step .grip { color: var(--text-3); flex-shrink: 0; }
.checkpoint-step.correct { border-color: var(--green); }
.checkpoint-step.incorrect { border-color: var(--red); }
.checkpoint-actions { margin-top: 12px; display: flex; gap: 10px; align-items: center; }
.checkpoint-check-btn {
  font-family: inherit; font-size: 13px; font-weight: 600;
  padding: 7px 14px; border-radius: 7px; cursor: pointer;
  border: 1px solid var(--border); background: var(--bg-2); color: var(--text);
}
.checkpoint-check-btn:hover { border-color: var(--accent); }
.checkpoint-result { font-size: 13px; font-weight: 600; }
.checkpoint-result.pass { color: var(--green); }
.checkpoint-result.fail { color: var(--red); }

/* ── Milestone paper callout ── */
.milestone-paper {
  margin-top: 18px; padding: 12px 14px;
  border-radius: 8px; border: 1px dashed var(--track-color, var(--accent));
  background: var(--bg-3); font-size: 13px; line-height: 1.5;
}
.milestone-paper strong { color: var(--track-color, var(--accent)); }

/* ── Footer ── */
.footer {
  text-align: center; padding: 14px 16px; font-size: 11px;
  color: var(--text-3); border-top: 1px solid var(--border-subtle); margin-top: auto;
}

/* ── Unlinked workbook planning page ── */
.workbook-hero {
  padding-bottom: 16px;
}

.workbook-content {
  max-width: 1120px;
}

.workbook-intro {
  max-width: 760px;
  margin-bottom: 24px;
  color: var(--text-2);
  font-size: 14px;
  line-height: 1.6;
}

.workbook-course-home {
  display: grid;
  gap: 20px;
}

.workbook-home-surface {
  align-items: start;
  display: grid;
  gap: 24px;
  grid-template-columns: 290px minmax(0, 1fr);
}

.workbook-route-panel {
  background: white;
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 24px 26px 28px;
}

.workbook-route-panel-header {
  align-items: center;
  border-bottom: 1px solid var(--border-subtle);
  display: flex;
  gap: 14px;
  padding-bottom: 18px;
}

.course-card-symbol {
  align-items: center;
  background: var(--accent);
  border-radius: 16px;
  color: white;
  display: inline-flex;
  font-family: Georgia, serif;
  font-size: 28px;
  height: 56px;
  justify-content: center;
  min-width: 56px;
}

.route-panel-title h2 {
  color: var(--text);
  font-size: 24px;
  line-height: 1.15;
  margin: 0;
}

.route-panel-title p {
  color: var(--text-2);
  font-size: 13px;
  line-height: 1.45;
  margin: 5px 0 0;
}

.workbook-home-route {
  display: grid;
  gap: 2px;
  margin: 24px 0 0;
  padding: 0;
}

.workbook-home-route button {
  appearance: none;
  align-items: center;
  background: transparent;
  border: 0;
  color: inherit;
  cursor: pointer;
  display: grid;
  gap: 14px;
  grid-template-columns: 58px minmax(0, 1fr);
  font-family: inherit;
  min-height: 76px;
  padding: 0;
  position: relative;
  text-align: left;
  width: 100%;
}

.workbook-home-route button::before {
  background: color-mix(in srgb, var(--accent) 18%, white);
  bottom: -18px;
  content: "";
  left: 27px;
  position: absolute;
  top: 54px;
  width: 3px;
}

.workbook-home-route button:last-child::before {
  display: none;
}

.workbook-home-route .route-node {
  background: white;
  border: 3px solid color-mix(in srgb, var(--accent) 55%, white);
  box-shadow: 0 4px 0 color-mix(in srgb, var(--accent) 18%, white);
  color: var(--accent);
  font-size: 15px;
  height: 42px;
  width: 42px;
}

.workbook-home-route button.done .route-node {
  background: var(--green);
  border-color: var(--green);
  color: white;
}

.home-route-text {
  display: grid;
  gap: 3px;
}

.home-route-text strong {
  color: var(--text);
  font-size: 16px;
  line-height: 1.25;
}

.home-route-text small {
  color: var(--text-3);
  font-size: 12px;
  font-weight: 700;
  text-transform: uppercase;
}

.workbook-course-column {
  background: var(--bg-2);
  border: 1px solid var(--border);
  border-radius: 12px;
  display: grid;
  gap: 8px;
  padding: 14px;
  position: sticky;
  top: 18px;
}

.home-course-pill {
  align-items: center;
  appearance: none;
  background: white;
  border: 1px solid var(--border-subtle);
  border-radius: 10px;
  color: var(--text);
  cursor: pointer;
  display: grid;
  gap: 9px;
  grid-template-columns: 32px minmax(0, 1fr);
  padding: 8px;
  text-align: left;
}

.home-course-pill.active {
  border-color: color-mix(in srgb, var(--accent) 55%, white);
  box-shadow: inset 3px 0 0 color-mix(in srgb, var(--accent) 55%, white);
}

.workbook-part {
  display: grid;
  gap: 10px;
}

.workbook-part + .workbook-part {
  border-top: 1px solid var(--border-subtle);
  padding-top: 12px;
}

.workbook-part-header {
  align-items: baseline;
  display: flex;
  justify-content: space-between;
  gap: 8px;
}

.workbook-part-header h2 {
  color: var(--text);
  font-size: 15px;
  margin: 0;
}

.workbook-part-header span {
  color: var(--text-3);
  font-size: 11px;
  font-weight: 800;
  letter-spacing: 0.4px;
  text-transform: uppercase;
}

.workbook-course-grid {
  display: grid;
  gap: 8px;
}

.workbook-course-card {
  align-items: center;
  appearance: none;
  background: white;
  border: 1px solid var(--border-subtle);
  border-radius: 10px;
  color: var(--text);
  cursor: pointer;
  display: grid;
  gap: 9px;
  grid-template-columns: 34px minmax(0, 1fr);
  padding: 9px;
  text-align: left;
}

.workbook-course-card.active {
  border-color: color-mix(in srgb, var(--accent) 55%, white);
  box-shadow: inset 3px 0 0 color-mix(in srgb, var(--accent) 55%, white);
}

.workbook-course-card .course-card-symbol {
  border-radius: 999px;
  font-size: 17px;
  height: 32px;
  min-width: 32px;
}

.course-card-body {
  display: grid;
  gap: 3px;
  min-width: 0;
}

.course-card-body strong {
  color: var(--text);
  font-size: 12px;
  line-height: 1.25;
}

.course-card-body small {
  color: var(--text-3);
  display: -webkit-box;
  font-size: 11px;
  line-height: 1.3;
  overflow: hidden;
  -webkit-box-orient: vertical;
  -webkit-line-clamp: 2;
}

.course-card-bar {
  display: none;
}

.workbook-root {
  display: flex;
  flex-direction: column;
  gap: 18px;
}

.workbook-home-surface {
  align-items: start;
  display: grid;
  gap: 28px;
  grid-template-columns: minmax(320px, 0.8fr) minmax(0, 1fr);
}

.workbook-course-column {
  background: transparent;
  border: 0;
  border-radius: 0;
  display: grid;
  gap: 28px;
  padding: 0;
  position: static;
}

.workbook-part {
  display: grid;
  gap: 8px;
}

.workbook-part + .workbook-part {
  border-top: 1px solid var(--border-subtle);
  padding-top: 18px;
}

.workbook-part-header {
  align-items: baseline;
  display: flex;
  gap: 9px;
}

.workbook-part-header h2 {
  color: var(--text);
  font-size: 16px;
  line-height: 1.2;
  margin: 0;
}

.workbook-part-header span,
.route-panel-title span {
  color: var(--text-3);
  font-size: 10px;
  font-weight: 800;
  letter-spacing: 0.7px;
  text-transform: uppercase;
}

.workbook-course-grid {
  display: grid;
  gap: 0;
  grid-template-columns: 1fr;
}

.workbook-course-card {
  align-items: center;
  appearance: none;
  background: transparent;
  border: 0;
  border-radius: 0;
  color: var(--text);
  cursor: pointer;
  display: grid;
  font-family: inherit;
  gap: 13px;
  grid-template-columns: 52px minmax(0, 1fr);
  min-height: 62px;
  padding: 0;
  position: relative;
  text-align: left;
}

.workbook-course-card::before {
  background: color-mix(in srgb, var(--accent) 18%, white);
  bottom: -9px;
  content: "";
  left: 25px;
  position: absolute;
  top: 45px;
  width: 3px;
}

.workbook-course-card:last-child::before {
  display: none;
}

.workbook-course-card:focus-visible {
  outline: 2px solid color-mix(in srgb, var(--accent) 25%, white);
  outline-offset: 2px;
}

.course-card-symbol {
  align-items: center;
  background: white;
  border: 3px solid color-mix(in srgb, var(--accent) 42%, white);
  border-radius: 999px;
  box-shadow: 0 3px 0 color-mix(in srgb, var(--accent) 15%, white);
  color: var(--accent);
  display: inline-flex;
  font-family: Georgia, serif;
  font-size: 20px;
  height: 40px;
  justify-content: center;
  line-height: 1;
  min-width: 40px;
  position: relative;
  width: 40px;
  z-index: 1;
}

.workbook-course-card.active .course-card-symbol {
  background: var(--accent);
  border-color: var(--accent);
  color: white;
}

.course-card-body {
  border-radius: 8px;
  display: grid;
  gap: 3px;
  min-width: 0;
  padding: 8px 10px;
}

.workbook-course-card.active .course-card-body,
.workbook-course-card:hover .course-card-body {
  background: var(--bg-2);
}

.course-card-body strong {
  color: var(--text);
  font-size: 14px;
  line-height: 1.25;
}

.course-card-body small,
.route-panel-progress {
  color: var(--text-3);
  font-size: 11px;
  line-height: 1.35;
}

.course-card-bar {
  display: none;
}

.workbook-route-panel {
  background: white;
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 16px;
  position: sticky;
  top: 18px;
}

.workbook-route-panel-header {
  align-items: center;
  border-bottom: 0;
  display: grid;
  gap: 12px;
  grid-template-columns: 40px minmax(0, 1fr);
  padding-bottom: 0;
}

.route-panel-title h2 {
  color: var(--text);
  font-size: 18px;
  line-height: 1.2;
  margin: 4px 0 0;
}

.route-panel-progress {
  margin: 10px 0 12px;
}

.workbook-home-route {
  display: grid;
  gap: 2px;
  margin: 0;
  padding: 0;
}

.workbook-home-route button,
.worksheet-back {
  appearance: none;
  background: transparent;
  border: 1px solid transparent;
  border-radius: 8px;
  color: var(--text-3);
  cursor: pointer;
  font-family: inherit;
}

.workbook-home-route button {
  align-items: center;
  display: grid;
  gap: 9px;
  grid-template-columns: 28px minmax(0, 1fr);
  min-height: 0;
  padding: 7px 6px;
  position: static;
  text-align: left;
  width: auto;
}

.workbook-home-route button::before {
  display: none;
}

.workbook-home-route button:hover,
.workbook-home-route button:focus-visible {
  background: var(--bg-2);
  border-color: var(--border-subtle);
  color: var(--text);
  outline: none;
}

.workbook-home-route .done .route-node {
  background: var(--green);
  border-color: var(--green);
  color: white;
}

.home-route-text {
  display: grid;
  gap: 2px;
  min-width: 0;
}

.home-route-text strong {
  color: var(--text);
  font-size: 12px;
  line-height: 1.25;
}

.home-route-text small {
  color: var(--text-3);
  font-size: 10px;
  font-weight: 800;
  letter-spacing: 0.4px;
  text-transform: uppercase;
}

.workbook-map-surface {
  display: grid;
  gap: 26px;
  grid-template-columns: minmax(0, 1.05fr) minmax(300px, 0.72fr);
}

.research-route-map {
  background:
    linear-gradient(90deg, transparent 49.8%, color-mix(in srgb, var(--accent) 12%, transparent) 50%, transparent 50.2%),
    white;
  border: 1px solid var(--border-subtle);
  border-radius: 18px;
  min-height: 560px;
  overflow: hidden;
  padding: 22px;
  position: relative;
}

.route-map-header {
  align-items: baseline;
  display: flex;
  justify-content: space-between;
  margin-bottom: 18px;
}

.route-map-header h2 {
  font-size: 18px;
  line-height: 1.2;
  margin: 0;
}

.route-map-header span,
.route-cluster-title {
  color: var(--text-3);
  font-size: 10px;
  font-weight: 800;
  letter-spacing: 0.7px;
  text-transform: uppercase;
}

.route-clusters {
  display: grid;
  gap: 14px;
}

.route-cluster {
  background: color-mix(in srgb, var(--bg-2) 62%, white);
  border: 1px solid color-mix(in srgb, var(--accent) 10%, var(--border-subtle));
  border-radius: 16px;
  display: grid;
  gap: 10px;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  padding: 13px;
  position: relative;
}

.route-cluster:nth-child(1) {
  margin-right: 20%;
}

.route-cluster:nth-child(2) {
  margin-left: 12%;
}

.route-cluster:nth-child(3) {
  margin-right: 8%;
}

.route-cluster-title {
  grid-column: 1 / -1;
  padding-left: 6px;
}

.route-choice {
  align-items: center;
  appearance: none;
  background: white;
  border: 1px solid var(--border-subtle);
  border-radius: 999px;
  box-shadow: 0 3px 0 color-mix(in srgb, var(--accent) 10%, white);
  color: var(--text);
  cursor: pointer;
  display: grid;
  font-family: inherit;
  gap: 10px;
  grid-template-columns: 46px minmax(0, 1fr);
  min-height: 58px;
  padding: 7px 12px 10px 7px;
  text-align: left;
}

.route-choice:hover,
.route-choice:focus-visible {
  border-color: color-mix(in srgb, var(--accent) 28%, var(--border));
  outline: none;
  transform: translateY(-1px);
}

.route-choice.active {
  background: color-mix(in srgb, var(--accent) 8%, white);
  border-color: color-mix(in srgb, var(--accent) 46%, var(--border));
  box-shadow: 0 4px 0 color-mix(in srgb, var(--accent) 22%, white);
}

.route-choice-orb {
  align-items: center;
  background: white;
  border: 3px solid color-mix(in srgb, var(--accent) 44%, white);
  border-radius: 50%;
  color: var(--accent);
  display: inline-flex;
  font-family: Georgia, serif;
  font-size: 18px;
  height: 38px;
  justify-content: center;
  line-height: 1;
  width: 38px;
}

.route-choice.active .route-choice-orb {
  background: var(--accent);
  border-color: var(--accent);
  color: white;
}

.route-choice-text {
  display: grid;
  gap: 1px;
  min-width: 0;
}

.route-choice-text strong {
  font-size: 13px;
  line-height: 1.2;
}

.route-choice-text small {
  color: var(--text-3);
  font-size: 10px;
  font-weight: 800;
}

.selected-route-path {
  border-radius: 18px;
  padding: 20px 18px 22px;
}

.selected-route-path .route-panel-progress {
  color: var(--text-2);
  font-size: 13px;
  margin: 12px 2px 18px;
}

.selected-route-path .workbook-home-route {
  display: grid;
  gap: 14px;
  justify-items: center;
  margin-top: 8px;
  position: relative;
}

.selected-route-path .workbook-home-route::before {
  background: color-mix(in srgb, var(--accent) 18%, white);
  bottom: 36px;
  content: "";
  left: 50%;
  position: absolute;
  top: 36px;
  transform: translateX(-50%);
  width: 4px;
}

.selected-route-path .workbook-home-route button {
  background: white;
  border: 0;
  border-radius: 18px;
  box-shadow: none;
  color: var(--text);
  display: grid;
  gap: 11px;
  grid-template-columns: 54px minmax(0, 1fr);
  justify-self: start;
  max-width: 315px;
  padding: 0;
  position: relative;
  width: 92%;
  z-index: 1;
}

.selected-route-path .workbook-home-route button:nth-child(even) {
  justify-self: end;
}

.selected-route-path .workbook-home-route .route-node {
  background: white;
  border: 4px solid color-mix(in srgb, var(--accent) 48%, white);
  border-radius: 50%;
  box-shadow: 0 5px 0 color-mix(in srgb, var(--accent) 15%, white);
  color: var(--accent);
  font-size: 18px;
  height: 48px;
  width: 48px;
}

.selected-route-path .workbook-home-route button:hover,
.selected-route-path .workbook-home-route button:focus-visible {
  background: transparent;
  border-color: transparent;
  color: var(--text);
}

.selected-route-path .home-route-text {
  background: white;
  border: 1px solid var(--border-subtle);
  border-radius: 13px;
  padding: 10px 12px;
}

.selected-route-path .home-route-text strong {
  font-size: 13px;
}

.worksheet-back {
  background: white;
  border-color: var(--border);
  color: var(--text-2);
  font-size: 12px;
  font-weight: 800;
  margin-bottom: 12px;
  padding: 8px 10px;
}

.worksheet-back:hover {
  border-color: var(--accent);
  color: var(--text);
}

.worksheet-layout {
  align-items: start;
  display: grid;
  gap: 30px;
  grid-template-columns: 340px minmax(0, 1fr);
}

.worksheet-toc {
  border-right: 1px solid var(--border-subtle);
  max-height: calc(100vh - 40px);
  overflow: auto;
  padding-right: 18px;
  position: sticky;
  top: 18px;
}

.worksheet-toc-title,
.worksheet-part-title {
  color: var(--text-3);
  font-size: 11px;
  font-weight: 800;
  letter-spacing: 0.8px;
  margin-bottom: 12px;
  text-transform: uppercase;
}

.worksheet-course-list {
  display: grid;
  gap: 8px;
}

.worksheet-part-title {
  border-top: 1px solid var(--border-subtle);
  margin: 10px 0 2px;
  padding-top: 12px;
}

.worksheet-course,
.worksheet-route-step {
  appearance: none;
  background: transparent;
  border: 1px solid transparent;
  border-radius: 8px;
  color: var(--text-3);
  cursor: pointer;
  font-family: inherit;
  font-size: 12px;
  text-align: left;
}

.worksheet-course {
  align-items: center;
  display: grid;
  gap: 9px;
  grid-template-columns: 34px minmax(0, 1fr) auto;
  padding: 8px 9px;
}

.worksheet-course:hover,
.worksheet-course.active {
  background: var(--bg-2);
  border-color: var(--border-subtle);
  color: var(--text);
}

.course-symbol {
  align-items: center;
  background: color-mix(in srgb, var(--accent) 8%, white);
  border: 1px solid color-mix(in srgb, var(--accent) 24%, white);
  border-radius: 999px;
  color: var(--accent);
  display: inline-flex;
  font-family: Georgia, serif;
  font-size: 17px;
  height: 30px;
  justify-content: center;
  line-height: 1;
  width: 30px;
}

.worksheet-course.active .course-symbol {
  background: var(--accent);
  color: white;
}

.course-text {
  display: grid;
  gap: 2px;
  min-width: 0;
}

.course-text strong,
.route-label strong {
  color: var(--text);
  font-size: 12px;
  line-height: 1.25;
}

.course-text small,
.route-label small {
  color: var(--text-3);
  display: -webkit-box;
  font-size: 11px;
  line-height: 1.35;
  overflow: hidden;
  -webkit-box-orient: vertical;
  -webkit-line-clamp: 2;
}

.course-progress {
  color: var(--text-3);
  font-size: 11px;
  font-variant-numeric: tabular-nums;
}

.worksheet-route {
  border-top: 1px solid var(--border-subtle);
  display: grid;
  gap: 0;
  margin-top: 18px;
  padding-top: 14px;
}

.worksheet-route-top {
  align-items: center;
  display: flex;
  justify-content: space-between;
  gap: 10px;
  margin-bottom: 8px;
}

.worksheet-route-top .worksheet-toc-title {
  margin: 0;
}

.worksheet-route-step {
  align-items: start;
  display: grid;
  gap: 10px;
  grid-template-columns: 28px minmax(0, 1fr);
  padding: 8px 7px;
  position: relative;
}

.worksheet-route-step::before {
  background: var(--border-subtle);
  bottom: -10px;
  content: "";
  left: 20px;
  position: absolute;
  top: 36px;
  width: 2px;
}

.worksheet-route-step:last-of-type::before {
  display: none;
}

.worksheet-route-step:hover,
.worksheet-route-step.active {
  background: var(--bg-2);
  border-color: var(--border-subtle);
  color: var(--text);
}

.route-node {
  align-items: center;
  background: white;
  border: 2px solid var(--border);
  border-radius: 999px;
  color: var(--text-3);
  display: inline-flex;
  font-size: 11px;
  font-weight: 900;
  height: 24px;
  justify-content: center;
  position: relative;
  width: 24px;
  z-index: 1;
}

.worksheet-route-step.active .route-node {
  background: var(--accent);
  border-color: var(--accent);
  color: white;
}

.worksheet-route-step.done .route-node {
  background: var(--green);
  border-color: var(--green);
  color: white;
}

.route-label {
  display: grid;
  gap: 3px;
}

.worksheet-reward {
  background: #f2fbf6;
  border: 1px solid color-mix(in srgb, var(--green) 45%, var(--border));
  border-radius: 8px;
  color: var(--green);
  font-size: 12px;
  font-weight: 800;
  margin-top: 10px;
  padding: 10px;
}

.worksheet-main {
  min-width: 0;
}

.worksheet-page {
  background: white;
  border: 1px solid var(--border);
  border-radius: 8px;
  color: var(--text);
  padding: 34px 40px 40px;
}

.worksheet-header {
  border-bottom: 1px solid var(--border-subtle);
  padding-bottom: 18px;
  position: relative;
}

.worksheet-kicker {
  color: var(--text-3);
  font-size: 11px;
  font-weight: 800;
  letter-spacing: 0.7px;
  margin-bottom: 10px;
  text-transform: uppercase;
}

.worksheet-header h2 {
  font-size: 30px;
  line-height: 1.15;
  margin: 0;
}

.worksheet-header p {
  color: var(--text);
  font-size: 17px;
  line-height: 1.6;
  margin: 14px 0 0;
  max-width: 820px;
}

.worksheet-header .workbook-level {
  position: absolute;
  right: 0;
  top: 0;
}

.worksheet-section {
  margin-top: 26px;
}

.worksheet-section h3,
.workbook-practice-header h4 {
  color: var(--text);
  font-size: 18px;
  letter-spacing: 0;
  margin: 0 0 12px;
  text-transform: none;
}

.worksheet-problems {
  counter-reset: problem;
  display: grid;
  gap: 18px;
  list-style: none;
  margin: 0;
  padding: 0;
}

.worksheet-problems li {
  border-top: 1px solid var(--border-subtle);
  color: var(--text);
  font-size: 15px;
  line-height: 1.55;
  padding: 14px 0 0 34px;
  position: relative;
}

.worksheet-problems li::before {
  align-items: center;
  background: var(--bg-2);
  border: 1px solid var(--border);
  border-radius: 999px;
  color: var(--text-2);
  content: counter(problem);
  counter-increment: problem;
  display: inline-flex;
  font-size: 12px;
  font-weight: 800;
  height: 22px;
  justify-content: center;
  left: 0;
  position: absolute;
  top: 14px;
  width: 22px;
}

.worksheet-answer-space {
  background-image: repeating-linear-gradient(to bottom, transparent 0, transparent 27px, var(--border-subtle) 28px);
  height: 84px;
  margin-top: 10px;
}

.worksheet-solution {
  border-top: 1px solid var(--border-subtle);
  padding-top: 24px;
}

.worksheet-scratch {
  background-image:
    linear-gradient(90deg, transparent 31px, #f1d7d7 32px, transparent 33px),
    repeating-linear-gradient(to bottom, white 0, white 27px, #e9eef7 28px);
  border: 1px solid var(--border-subtle);
  border-radius: 7px;
  height: 160px;
  margin-bottom: 12px;
}

.worksheet-latex-input {
  border: 1px solid var(--border);
  border-radius: 7px;
  box-sizing: border-box;
  color: var(--text);
  font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, monospace;
  font-size: 13px;
  line-height: 1.5;
  min-height: 110px;
  padding: 11px 12px;
  resize: vertical;
  width: 100%;
}

.worksheet-latex-input:focus {
  border-color: var(--accent);
  outline: 2px solid color-mix(in srgb, var(--accent) 16%, white);
}

.worksheet-solution-actions {
  display: flex;
  gap: 8px;
  margin-top: 10px;
}

.worksheet-solution-actions button,
.worksheet-check-button {
  appearance: none;
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: 7px;
  color: var(--text);
  cursor: pointer;
  font-family: inherit;
  font-size: 12px;
  font-weight: 800;
  padding: 8px 10px;
}

.worksheet-solution-actions button:hover,
.worksheet-check-button:hover {
  border-color: var(--accent);
}

.worksheet-solution-actions button.complete {
  background: var(--text);
  color: white;
}

.worksheet-solution-actions button.is-complete {
  background: var(--green);
  border-color: var(--green);
}

.worksheet-solution-preview {
  background: #fbfbfc;
  border: 1px solid var(--border-subtle);
  border-radius: 7px;
  color: var(--text-2);
  margin-top: 10px;
  min-height: 44px;
  overflow-x: auto;
  padding: 12px 14px;
}

.workbook-path-map {
  border-top: 1px solid var(--border-subtle);
  padding-top: 18px;
}

.workbook-progress {
  align-items: center;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: var(--bg-2);
  display: grid;
  grid-template-columns: minmax(160px, 1fr) minmax(180px, 2fr) auto;
  gap: 12px;
  padding: 12px 14px;
}

.workbook-progress-label {
  display: grid;
  gap: 3px;
}

.workbook-progress-label span {
  color: var(--text-3);
  font-size: 10px;
  font-weight: 800;
  letter-spacing: 0.5px;
  text-transform: uppercase;
}

.workbook-progress-label strong {
  color: var(--text);
  font-size: 13px;
}

.workbook-progress-bar {
  background: var(--bg-3);
  border: 1px solid var(--border-subtle);
  border-radius: 999px;
  height: 9px;
  overflow: hidden;
}

.workbook-progress-bar span {
  background: var(--accent);
  display: block;
  height: 100%;
  transition: width 160ms ease;
  width: 0;
}

.workbook-progress-reset {
  appearance: none;
  border: 1px solid var(--border);
  border-radius: 7px;
  background: var(--bg);
  color: var(--text-2);
  cursor: pointer;
  font-size: 11px;
  font-weight: 700;
  padding: 7px 9px;
}

.workbook-progress-reset:hover {
  border-color: var(--accent);
  color: var(--text);
}

.workbook-path-top {
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  gap: 18px;
  margin-bottom: 12px;
}

.workbook-path-top h2 {
  margin: 0;
  color: var(--text);
  font-size: 18px;
}

.workbook-path-top p {
  max-width: 620px;
  margin: 0;
  color: var(--text-3);
  font-size: 12px;
  line-height: 1.5;
}

.workbook-lanes {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 10px;
}

.workbook-lane {
  appearance: none;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: var(--bg-2);
  color: var(--text);
  cursor: pointer;
  display: grid;
  gap: 8px;
  padding: 13px 14px;
  text-align: left;
}

.workbook-lane:hover {
  border-color: var(--accent);
}

.lane-title {
  font-size: 13px;
  font-weight: 750;
  line-height: 1.25;
}

.lane-count {
  color: var(--text-3);
  font-size: 11px;
  text-transform: uppercase;
}

.lane-dots {
  display: flex;
  gap: 6px;
}

.lane-dot {
  align-items: center;
  border-radius: 999px;
  color: white;
  display: inline-flex;
  font-size: 10px;
  font-weight: 800;
  height: 20px;
  justify-content: center;
  min-width: 20px;
  padding: 0 6px;
}

.lane-dot.early { background: #0284c7; }
.lane-dot.foundation { background: #0f766e; }
.lane-dot.intermediate { background: #7c3aed; }
.lane-dot.advanced { background: #be123c; }

.workbook-meta,
.workbook-track {
  border-top: 1px solid var(--border-subtle);
  padding-top: 18px;
}

.workbook-meta h2,
.workbook-track h2 {
  margin: 0 0 8px;
  font-size: 17px;
  color: var(--text);
}

.workbook-meta p {
  margin: 0;
  color: var(--text-3);
  font-size: 12px;
  line-height: 1.5;
}

.workbook-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 14px;
  margin-top: 12px;
}

.workbook-card {
  border: 1px solid var(--border);
  border-radius: 8px;
  background: var(--bg-2);
  padding: 18px 20px;
}

.workbook-card.practice-open {
  border-color: color-mix(in srgb, var(--accent) 45%, var(--border));
}

.workbook-card-top {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 12px;
}

.workbook-title-block {
  min-width: 0;
}

.workbook-card h3 {
  margin: 0;
  color: var(--text);
  font-size: 20px;
  line-height: 1.3;
}

.workbook-title-block p {
  margin: 5px 0 0;
  color: var(--text-3);
  font-size: 12px;
  line-height: 1.4;
}

.workbook-level {
  flex-shrink: 0;
  border: 1px solid var(--border);
  border-radius: 999px;
  color: var(--text-3);
  font-size: 10px;
  font-weight: 700;
  letter-spacing: 0.5px;
  padding: 3px 7px;
  text-transform: uppercase;
}

.workbook-result,
.workbook-why {
  margin: 12px 0 0;
  color: var(--text-2);
  font-size: 16px;
  line-height: 1.65;
}

.workbook-result {
  color: var(--text);
}

.workbook-equations {
  border-top: 0;
  margin-top: 26px;
  padding-top: 0;
}

.workbook-equations h4 {
  margin: 0 0 12px;
  color: var(--text);
  font-size: 18px;
  font-weight: 800;
  letter-spacing: 0;
  text-transform: none;
}

.workbook-equation {
  background: #fbfbfc;
  border: 1px solid var(--border-subtle);
  border-radius: 7px;
  margin: 9px 0;
  overflow-x: auto;
  padding: 13px 16px;
}

.workbook-details {
  display: grid;
  grid-template-columns: minmax(180px, 0.7fr) minmax(260px, 1.3fr);
  gap: 18px;
  margin-top: 16px;
}

.workbook-detail-block h4 {
  margin: 0 0 6px;
  color: var(--text-3);
  font-size: 11px;
  letter-spacing: 0.6px;
  text-transform: uppercase;
}

.workbook-task-list {
  margin: 0;
  padding-left: 17px;
}

.workbook-task-list li {
  color: var(--text-2);
  font-size: 13px;
  line-height: 1.5;
  margin-bottom: 5px;
}

.workbook-mini-chips {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
}

.workbook-mini-chips span {
  border: 1px solid var(--border-subtle);
  border-radius: 999px;
  color: var(--text-2);
  font-size: 11px;
  line-height: 1.3;
  padding: 4px 7px;
}

.workbook-targets {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  margin-top: 13px;
}

.workbook-targets a {
  color: var(--accent);
  border: 1px solid var(--border-subtle);
  border-radius: 999px;
  font-size: 11px;
  padding: 4px 7px;
  text-decoration: none;
}

.workbook-targets a:hover {
  border-color: var(--accent);
}

.workbook-source {
  margin-top: 13px;
  padding-top: 11px;
  border-top: 1px solid var(--border-subtle);
}

.workbook-source-counts {
  color: var(--text-3);
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.4px;
  text-transform: uppercase;
}

.workbook-source-samples {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  margin-top: 8px;
}

.workbook-source-samples span {
  max-width: 100%;
  border: 1px solid var(--border-subtle);
  border-radius: 999px;
  color: var(--text-2);
  font-size: 11px;
  line-height: 1.35;
  overflow: hidden;
  padding: 4px 7px;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.workbook-equation mjx-container[jax="CHTML"][display="true"] {
  margin: 0;
  min-width: max-content;
  padding: 2px 0;
}

.workbook-card mjx-container {
  color: var(--text);
}

.workbook-practice-toggle,
.practice-reveal-btn {
  appearance: none;
  border: 1px solid var(--border);
  border-radius: 7px;
  background: var(--bg);
  color: var(--text);
  cursor: pointer;
  font-size: 12px;
  font-weight: 700;
  margin-top: 13px;
  padding: 8px 10px;
}

.workbook-practice-toggle:hover,
.practice-reveal-btn:hover {
  border-color: var(--accent);
}

.workbook-practice {
  display: grid;
  gap: 12px;
  margin-top: 0;
}

.workbook-practice-header {
  align-items: center;
  display: flex;
  justify-content: space-between;
  gap: 12px;
}

.workbook-practice-header h4 {
  margin: 0;
}

.workbook-practice-header span {
  color: var(--text-3);
  font-size: 11px;
  text-transform: uppercase;
}

.practice-card {
  border: 1px solid var(--border-subtle);
  border-radius: 8px;
  background: #fbfbfc;
  padding: 14px 16px;
}

.practice-card.practice-done {
  border-color: color-mix(in srgb, var(--green) 50%, var(--border));
  box-shadow: inset 3px 0 0 var(--green);
}

.practice-prompt,
.practice-body,
.practice-hint,
.practice-answer,
.practice-feedback,
.practice-label {
  margin: 0;
  font-size: 14px;
  line-height: 1.55;
}

.practice-prompt {
  color: var(--text);
  font-weight: 650;
}

.practice-body,
.practice-hint {
  color: var(--text-2);
  margin-top: 7px;
}

.practice-label {
  color: var(--text-3);
  font-size: 11px;
  font-weight: 800;
  letter-spacing: 0.5px;
  margin-bottom: 5px;
  text-transform: uppercase;
}

.practice-options {
  display: grid;
  gap: 7px;
  margin-top: 10px;
}

.practice-options button {
  appearance: none;
  border: 1px solid var(--border);
  border-radius: 7px;
  background: var(--bg-2);
  color: var(--text-2);
  cursor: pointer;
  font-size: 13px;
  line-height: 1.35;
  padding: 8px 9px;
  text-align: left;
}

.practice-options button:not(:disabled):hover {
  border-color: var(--accent);
  color: var(--text);
}

.practice-options button.correct {
  border-color: var(--green);
}

.practice-options button.picked-wrong {
  border-color: var(--red);
}

.practice-feedback {
  color: var(--text-3);
  margin-top: 9px;
}

.practice-feedback.pass { color: var(--green); }
.practice-feedback.fail { color: var(--red); }

.practice-answer {
  border-left: 2px solid var(--accent);
  color: var(--text-2);
  margin-top: 9px;
  padding-left: 9px;
}

@media (max-width: 600px) {
  .learn-hero { padding: 36px 16px 18px; }
  .learn-content { padding: 0 16px 32px; }
  .learn-home-panel { grid-template-columns: 1fr; }
  .track-nodes { grid-template-columns: 1fr; }
  .node-panel { padding: 22px 18px; }
  .workbook-path-top { align-items: flex-start; flex-direction: column; }
  .workbook-progress { grid-template-columns: 1fr; }
  .workbook-details { grid-template-columns: 1fr; }
  .workbook-card { padding: 16px; }
  .workbook-card h3 { font-size: 17px; }
  .workbook-home-surface { grid-template-columns: 1fr; }
  .workbook-course-grid { grid-template-columns: 1fr; }
  .workbook-route-panel { position: static; }
  .worksheet-layout { grid-template-columns: 1fr; }
  .worksheet-toc {
    border-right: 0;
    border-bottom: 1px solid var(--border-subtle);
    max-height: 240px;
    padding: 0 0 16px;
    position: static;
  }
  .worksheet-page { padding: 24px 18px 28px; }
  .worksheet-header h2 { font-size: 24px; }
  .worksheet-header .workbook-level { position: static; margin-top: 12px; display: inline-flex; }
}

/* ============================================================
   Workbooks v2 — Duolingo-style path UI (11 research tracks)
   All classes are wb-* and self-contained.
   ============================================================ */
.wb-map { max-width: 720px; margin: 0 auto; padding: 8px 16px 64px; }

.wb-status {
  position: sticky; top: 8px; z-index: 5;
  display: flex; align-items: center; gap: 12px;
  padding: 10px 16px; margin-bottom: 20px;
  background: var(--bg-2); border: 1px solid var(--border);
  border-radius: 14px; box-shadow: 0 2px 8px rgba(0,0,0,0.05);
}
.wb-status-streak { font-weight: 700; font-size: 14px; color: var(--orange); white-space: nowrap; }
.wb-status-bar { flex: 1; height: 12px; background: var(--bg-3); border-radius: 8px; overflow: hidden; }
.wb-status-fill { display: block; height: 100%; background: var(--green); border-radius: 8px; transition: width .4s ease; }
.wb-status-pct { font-weight: 700; font-size: 13px; color: var(--text-2); min-width: 34px; text-align: right; }

.wb-intro { text-align: center; margin-bottom: 28px; }
.wb-intro h2 { font-size: 24px; margin: 0 0 6px; color: var(--text); }
.wb-intro p { margin: 0 auto; max-width: 460px; color: var(--text-2); font-size: 14px; line-height: 1.5; }

/* unit (one of the 11 tracks) */
.wb-unit { margin-bottom: 36px; }
.wb-unit-head {
  display: flex; align-items: center; gap: 14px;
  padding: 14px 18px; border-radius: 14px; color: var(--text);
  background: var(--bg-2);
  border: 1px solid var(--border);
  box-shadow: none;
}
.wb-unit-head-text { flex: 1; min-width: 0; }
.wb-unit-head-text h3 { margin: 0; font-size: 17px; font-weight: 800; }
.wb-unit-head-text p { margin: 3px 0 0; font-size: 12.5px; color: var(--text-2); }

/* the winding path */
.wb-path { position: relative; padding: 26px 0 6px; }
.wb-path::before {
  content: ""; position: absolute; top: 0; bottom: 24px; left: 50%;
  width: 3px; transform: translateX(-50%);
  background: repeating-linear-gradient(var(--border) 0 8px, transparent 8px 16px);
}
.wb-node-slot {
  position: relative; z-index: 1;
  display: flex; flex-direction: column; align-items: center; gap: 8px;
  margin-bottom: 18px;
}
.wb-node-slot.pos-0 { transform: translateX(0); }
.wb-node-slot.pos-1 { transform: translateX(84px); }
.wb-node-slot.pos-2 { transform: translateX(0); }
.wb-node-slot.pos-3 { transform: translateX(-84px); }

.wb-node {
  width: 74px; height: 74px; border-radius: 50%; border: none; cursor: pointer;
  font-size: 24px; font-weight: 800; color: #fff;
  display: grid; place-items: center; position: relative;
  transition: transform .08s ease;
}
.wb-node-glyph { line-height: 1; }
.wb-node:active { transform: translateY(4px); }

.wb-node.done {
  background: var(--green);
  box-shadow: 0 6px 0 #1b5e20;
}
.wb-node.open {
  background: var(--accent);
  box-shadow: 0 6px 0 var(--accent-hover);
}
.wb-node.done:active { box-shadow: 0 2px 0 #1b5e20; }
.wb-node.open:active { box-shadow: 0 2px 0 var(--accent-hover); }
.wb-node.frontier.open,
.wb-node.frontier.done {
  box-shadow: 0 0 0 4px var(--accent-bg), 0 6px 0 var(--accent-hover);
}

.wb-node-pulse {
  position: absolute; inset: -6px; border-radius: 50%;
  border: 3px solid var(--green); opacity: 0.6;
  animation: wb-pulse 1.6s ease-out infinite;
}
@keyframes wb-pulse {
  0% { transform: scale(1); opacity: 0.6; }
  100% { transform: scale(1.45); opacity: 0; }
}
.wb-node-label {
  font-size: 12px; font-weight: 600; color: var(--text-2);
  max-width: 150px; text-align: center; line-height: 1.3;
}
.wb-node-slot.nudge { animation: wb-shake .4s; }
@keyframes wb-shake {
  0%,100%{transform:translateX(var(--nx,0));}
  20%{transform:translateX(-6px);}40%{transform:translateX(6px);}
  60%{transform:translateX(-4px);}80%{transform:translateX(4px);}
}

.wb-map-foot { text-align: center; margin-top: 24px; }
.wb-reset {
  background: none; border: 1px solid var(--border); color: var(--text-3);
  padding: 8px 16px; border-radius: 10px; font-size: 13px; cursor: pointer;
}
.wb-reset:hover { color: var(--text-2); border-color: var(--text-3); }

/* ---------- lesson view ---------- */
.wb-lesson { max-width: 760px; margin: 0 auto; padding: 8px 16px 80px; }
.wb-lesson-top { display: flex; align-items: center; justify-content: space-between; gap: 12px; margin-bottom: 18px; }
.wb-lesson-back {
  background: none; border: none; color: var(--accent); font-weight: 700;
  font-size: 14px; cursor: pointer; padding: 6px 0;
}
.wb-lesson-kicker {
  font-size: 12px; font-weight: 700; color: var(--accent); padding: 6px 12px; border-radius: 10px;
  background: var(--accent-bg);
}
.wb-lesson-title { font-size: 26px; margin: 0 0 8px; color: var(--text); }
.wb-lesson-goal {
  font-size: 15px; line-height: 1.55; color: var(--text); margin: 0 0 18px;
  padding: 12px 16px; background: var(--accent-bg); border-radius: 12px;
  border-left: 4px solid var(--accent);
}
.wb-eq-panel { display: grid; gap: 10px; margin-bottom: 22px; }
.wb-eq { background: var(--bg-2); border: 1px solid var(--border); border-radius: 10px; padding: 12px 14px; overflow-x: auto; }

.wb-setup, .wb-goal { font-size: 14px; line-height: 1.5; padding: 10px 14px; border-radius: 10px; margin-bottom: 10px; }
.wb-setup { background: var(--bg-2); border: 1px solid var(--border); }
.wb-goal { background: var(--green-bg); color: var(--text); }

.wb-steps { list-style: none; counter-reset: wb; padding: 0; margin: 0; display: grid; gap: 14px; }
.wb-step {
  position: relative; counter-increment: wb;
  background: var(--bg); border: 1px solid var(--border); border-radius: 14px;
  padding: 16px 18px 16px 56px;
}
.wb-step::before {
  content: counter(wb); position: absolute; left: 14px; top: 16px;
  width: 28px; height: 28px; border-radius: 50%;
  background: var(--accent); color: #fff;
  display: grid; place-items: center; font-weight: 800; font-size: 13px;
}
.wb-step-prompt { margin: 0 0 8px; font-size: 14.5px; line-height: 1.5; color: var(--text); }
.wb-step-eq { background: var(--bg-2); border-radius: 8px; padding: 8px 12px; margin: 6px 0; overflow-x: auto; }
.wb-reveal-btn {
  background: none; border: 1px solid var(--border); color: var(--text-2);
  font-size: 12.5px; font-weight: 600; padding: 5px 12px; border-radius: 8px; cursor: pointer;
}
.wb-reveal-btn:hover { border-color: var(--accent); color: var(--accent); }
.wb-reveal { margin-top: 8px; background: var(--green-bg); border-radius: 8px; padding: 8px 12px; overflow-x: auto; }

.wb-exercises { margin-top: 26px; }
.wb-exercises h4 { font-size: 16px; margin: 0 0 12px; }
.wb-ex-card { background: var(--bg-2); border: 1px solid var(--border); border-radius: 14px; padding: 16px; margin-bottom: 12px; }
.wb-ex-prompt { margin: 0 0 10px; font-size: 14px; line-height: 1.5; }
.wb-ex-options { display: grid; gap: 8px; }
.wb-ex-opt { text-align: left; padding: 10px 14px; border: 2px solid var(--border); background: var(--bg); border-radius: 10px; font-size: 13.5px; cursor: pointer; }
.wb-ex-opt:hover:not(.answered) { border-color: var(--accent); }
.wb-ex-opt.correct { border-color: var(--green); background: var(--green-bg); }
.wb-ex-opt.wrong { border-color: var(--red); background: var(--red-bg); }
.wb-ex-opt.answered { cursor: default; }
.wb-ex-explain { margin: 10px 0 0; font-size: 13px; line-height: 1.5; color: var(--text-2); }
.wb-ex-hint { font-size: 13px; color: var(--text-2); margin: 0 0 8px; }

.wb-lesson-footer { margin-top: 32px; text-align: center; }
.wb-complete {
  background: var(--green); color: #fff; border: none; font-weight: 800; font-size: 16px;
  padding: 14px 40px; border-radius: 14px; cursor: pointer; box-shadow: 0 5px 0 #1b5e20;
  transition: transform .08s ease;
}
.wb-complete:active { transform: translateY(3px); box-shadow: 0 2px 0 #1b5e20; }
.wb-complete.is-done { background: var(--bg-3); color: var(--green); box-shadow: 0 5px 0 var(--border); }
.wb-toast { margin-top: 14px; font-weight: 700; color: var(--text-2); }

@media (max-width: 560px) {
  .wb-node-slot.pos-1 { transform: translateX(52px); }
  .wb-node-slot.pos-3 { transform: translateX(-52px); }
  .wb-node { width: 64px; height: 64px; font-size: 20px; }
}