/* ─────────────────────────────────────────────────────────────
 * Thier — interactive lesson player
 *
 * Loaded only on /learn/<track>/<lesson> pages. Designed to look
 * native to the Thier brand (teal accents, rounded surfaces,
 * generous spacing) without leaning on the iOS-target SwiftUI
 * components.
 *
 * Class prefix: `tlp-` (Thier Lesson Player) — keeps everything
 * scoped so it can't collide with global `.lesson-*` classes used
 * by api-lesson.js (the legacy /lesson/{id} route).
 * ───────────────────────────────────────────────────────────── */

/* ─── 1. Page chrome ───────────────────────────────────────── */

.tlp-page {
  position: relative;
  isolation: isolate;
  min-height: 100vh;
  padding: 116px 0 100px;
  overflow: hidden;
}
.tlp-page::before,
.tlp-page::after {
  content: "";
  position: absolute;
  border-radius: 50%;
  filter: blur(120px);
  opacity: 0.4;
  z-index: -1;
  pointer-events: none;
}
.tlp-page::before {
  width: 520px; height: 520px;
  top: -160px; left: -180px;
  background: radial-gradient(circle, rgba(125,215,195,0.55), transparent 70%);
}
.tlp-page::after {
  width: 600px; height: 600px;
  top: 80px; right: -240px;
  background: radial-gradient(circle, rgba(52,168,146,0.30), transparent 70%);
}
@media (max-width: 520px) {
  .tlp-page { padding: 96px 0 80px; }
}

/* ─── 2. Sticky progress bar ──────────────────────────────── */

.tlp-progress-rail {
  position: fixed;
  top: 64px;
  left: 0; right: 0;
  height: 3px;
  background: rgba(52,168,146,0.10);
  z-index: 40;
}
.tlp-progress-fill {
  height: 100%;
  background: linear-gradient(90deg, #34a892 0%, #5ec7b1 100%);
  width: 0%;
  transition: width 240ms ease-out;
  box-shadow: 0 0 12px rgba(52,168,146,0.35);
}

/* ─── 3. Shell + hero ─────────────────────────────────────── */

.tlp-shell {
  width: min(720px, calc(100% - 2.5rem));
  margin: 0 auto;
  display: grid;
  gap: 18px;
}

.tlp-cta {
  display: flex;
  align-items: center;
  gap: 16px;
  flex-wrap: wrap;
  padding: clamp(14px, 2vw, 18px) clamp(16px, 2.4vw, 22px);
  background: linear-gradient(180deg, rgba(255,255,255,0.82), rgba(248,253,250,0.66));
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-soft);
}
.tlp-cta-icon {
  width: 38px; height: 38px;
  border-radius: 12px;
  background: rgba(52,168,146,0.12);
  color: var(--teal-deep);
  display: grid; place-items: center;
  flex-shrink: 0;
}
.tlp-cta-icon svg { width: 20px; height: 20px; }
.tlp-cta-text {
  flex: 1; min-width: 0;
  color: var(--ink-soft);
  font-size: 0.95rem; line-height: 1.4;
}
.tlp-cta-text strong { color: var(--ink); font-weight: 600; }

.tlp-hero {
  padding: clamp(28px, 4.6vw, 44px) clamp(28px, 4.6vw, 44px) clamp(20px, 3vw, 28px);
  background: var(--surface-strong);
  border: 1px solid var(--line);
  border-radius: var(--radius-xl);
  box-shadow: var(--shadow-panel);
}
.tlp-eyebrow {
  display: inline-flex; align-items: center; gap: 0.4rem;
  padding: 0.36rem 0.7rem; border-radius: 999px;
  font-size: 0.7rem; font-weight: 700;
  letter-spacing: 0.1em; text-transform: uppercase;
  background: rgba(52,168,146,0.14); color: var(--teal-deep);
  margin-bottom: 14px;
}
.tlp-eyebrow a { color: inherit; text-decoration: none; }
.tlp-eyebrow a:hover { text-decoration: underline; }
.tlp-title {
  margin: 0 0 14px;
  font-size: clamp(1.8rem, 4.4vw, 2.6rem);
  line-height: 1.05;
  letter-spacing: -0.03em;
  font-weight: 700;
  color: var(--ink);
}
.tlp-meta {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
  color: var(--ink-muted);
  font-size: 0.9rem;
}
.tlp-meta span { display: inline-flex; align-items: center; gap: 6px; }
.tlp-meta svg { width: 14px; height: 14px; }

/* ─── 4. Cards container ──────────────────────────────────── */

.tlp-content {
  display: grid; gap: 14px;
}
.tlp-card {
  padding: 22px 24px;
  border-radius: var(--radius-lg);
  background: var(--surface-strong);
  border: 1px solid var(--line);
  box-shadow: var(--shadow-soft);
  position: relative;
}

.tlp-card-tag {
  display: inline-flex;
  font-size: 0.66rem; font-weight: 700;
  letter-spacing: 0.12em; text-transform: uppercase;
  color: var(--ink-muted);
  margin-bottom: 10px;
}
.tlp-card-title {
  margin: 0 0 10px;
  font-size: 1.18rem;
  line-height: 1.3;
  letter-spacing: -0.01em;
  font-weight: 650;
  color: var(--ink);
}
.tlp-card-body {
  margin: 0;
  color: var(--ink-soft);
  font-size: 1rem;
  line-height: 1.6;
  white-space: pre-wrap;
  word-wrap: break-word;
}
.tlp-card-body + .tlp-card-body { margin-top: 12px; }

.tlp-card-intro {
  background: linear-gradient(180deg, rgba(255,255,255,0.94) 0%, rgba(244,252,248,0.80) 100%);
  border-color: rgba(52,168,146,0.22);
}
.tlp-card-intro .tlp-card-title { font-size: 1.34rem; }
.tlp-card-intro .tlp-card-body  { font-size: 1.05rem; }

.tlp-card-fact .tlp-card-tag    { color: var(--teal-deep); }
.tlp-card-fact                  { border-color: rgba(52,168,146,0.18); }
.tlp-card-insight .tlp-card-tag { color: #b85a46; }
.tlp-card-insight {
  background: linear-gradient(180deg, rgba(255,243,233,0.80) 0%, rgba(255,237,221,0.55) 100%);
  border-color: rgba(184,90,70,0.20);
}
.tlp-card-takeaway {
  background: linear-gradient(180deg, rgba(185,232,221,0.55) 0%, rgba(234,248,243,0.70) 100%);
  border-color: rgba(52,168,146,0.30);
}
.tlp-card-takeaway .tlp-card-tag   { color: var(--teal-deep); }
.tlp-card-takeaway .tlp-card-title { color: var(--teal-deep); }

/* Stat callout in the visual block of an intro card */
.tlp-card-stat {
  margin-top: 14px;
  display: inline-flex; flex-direction: column;
  padding: 10px 14px;
  background: rgba(52,168,146,0.10);
  border: 1px solid rgba(52,168,146,0.20);
  border-radius: var(--radius-md);
}
.tlp-card-stat-value {
  font-size: 1.4rem; font-weight: 700;
  color: var(--teal-deep);
  letter-spacing: -0.02em;
  font-variant-numeric: tabular-nums;
}
.tlp-card-stat-label {
  font-size: 0.78rem; font-weight: 500;
  color: var(--ink-muted);
  margin-top: 2px;
}

/* ─── 5. Quiz card ────────────────────────────────────────── */

.tlp-card-quiz .tlp-card-tag { color: var(--teal-deep); }
.tlp-quiz-options {
  display: grid; gap: 10px;
  margin-top: 14px;
}
.tlp-quiz-option {
  display: flex; align-items: center; gap: 12px;
  padding: 14px 16px;
  border-radius: var(--radius-md);
  background: rgba(255, 255, 255, 0.85);
  border: 1px solid var(--line);
  text-align: left;
  font: inherit;
  font-size: 0.97rem;
  color: var(--ink);
  cursor: pointer;
  transition: all 120ms ease;
  width: 100%;
}
.tlp-quiz-option:hover:not([disabled]) {
  background: rgba(52,168,146,0.06);
  border-color: rgba(52,168,146,0.40);
}
.tlp-quiz-option[disabled] { cursor: default; opacity: 0.85; }
.tlp-quiz-option-marker {
  width: 22px; height: 22px;
  flex-shrink: 0;
  border-radius: 50%;
  border: 2px solid var(--ink-muted);
  display: grid; place-items: center;
  font-size: 0.72rem; font-weight: 700;
  color: var(--ink-muted);
  background: white;
}
.tlp-quiz-option-text { flex: 1; }
.tlp-quiz-option.is-correct {
  background: rgba(52,168,146,0.12);
  border-color: rgba(52,168,146,0.55);
  color: var(--teal-deep);
}
.tlp-quiz-option.is-correct .tlp-quiz-option-marker {
  background: var(--teal-deep);
  border-color: var(--teal-deep);
  color: white;
}
.tlp-quiz-option.is-incorrect {
  background: rgba(184,90,70,0.10);
  border-color: rgba(184,90,70,0.45);
  color: #8a3f2e;
}
.tlp-quiz-option.is-incorrect .tlp-quiz-option-marker {
  background: #b85a46;
  border-color: #b85a46;
  color: white;
}
.tlp-quiz-feedback {
  margin-top: 14px;
  padding: 14px 16px;
  border-radius: var(--radius-md);
  background: rgba(52,168,146,0.08);
  border: 1px solid rgba(52,168,146,0.20);
  color: var(--ink-soft);
  font-size: 0.95rem;
  line-height: 1.5;
  display: none;
}
.tlp-quiz-feedback strong { color: var(--ink); }
.tlp-quiz-feedback.is-shown { display: block; }
.tlp-quiz-feedback.is-incorrect {
  background: rgba(184,90,70,0.08);
  border-color: rgba(184,90,70,0.20);
}

/* ─── 6. True/False card ──────────────────────────────────── */

.tlp-tf-statement {
  margin: 14px 0;
  padding: 16px 18px;
  border-radius: var(--radius-md);
  background: rgba(52,168,146,0.06);
  border: 1px solid rgba(52,168,146,0.14);
  font-style: italic;
  color: var(--ink);
  font-size: 1.03rem;
  line-height: 1.5;
}
.tlp-tf-buttons {
  display: flex; gap: 10px;
  margin-top: 6px;
}
.tlp-tf-button {
  flex: 1;
  padding: 14px 16px;
  border-radius: var(--radius-md);
  border: 1px solid var(--line);
  background: white;
  color: var(--ink);
  font: inherit;
  font-weight: 600;
  font-size: 1rem;
  cursor: pointer;
  transition: all 120ms ease;
}
.tlp-tf-button:hover:not([disabled]) {
  background: rgba(52,168,146,0.08);
  border-color: rgba(52,168,146,0.45);
}
.tlp-tf-button[disabled] { cursor: default; }
.tlp-tf-button.is-correct {
  background: rgba(52,168,146,0.14);
  border-color: rgba(52,168,146,0.55);
  color: var(--teal-deep);
}
.tlp-tf-button.is-incorrect {
  background: rgba(184,90,70,0.10);
  border-color: rgba(184,90,70,0.45);
  color: #8a3f2e;
}

/* ─── 7. Fill in blank ────────────────────────────────────── */

.tlp-fib-sentence {
  margin: 12px 0 14px;
  font-size: 1.05rem;
  line-height: 1.6;
  color: var(--ink);
}
.tlp-fib-blank {
  display: inline-flex;
  min-width: 80px;
  padding: 2px 14px;
  border-bottom: 2px solid rgba(52,168,146,0.40);
  color: var(--teal-deep);
  font-weight: 600;
}
.tlp-fib-options {
  display: flex; gap: 10px; flex-wrap: wrap;
}
.tlp-fib-option {
  padding: 10px 18px;
  border-radius: 999px;
  border: 1px solid var(--line);
  background: white;
  color: var(--ink);
  font: inherit;
  font-size: 0.95rem;
  font-weight: 600;
  cursor: pointer;
  transition: all 120ms ease;
}
.tlp-fib-option:hover:not([disabled]) {
  background: rgba(52,168,146,0.08);
  border-color: rgba(52,168,146,0.45);
}
.tlp-fib-option.is-correct {
  background: rgba(52,168,146,0.14);
  border-color: rgba(52,168,146,0.55);
  color: var(--teal-deep);
}
.tlp-fib-option.is-incorrect {
  background: rgba(184,90,70,0.10);
  border-color: rgba(184,90,70,0.45);
  color: #8a3f2e;
}
.tlp-fib-option[disabled] { cursor: default; opacity: 0.6; }

/* ─── 8. MultiSelect ──────────────────────────────────────── */

.tlp-ms-options { display: grid; gap: 8px; margin: 14px 0; }
.tlp-ms-option {
  display: flex; align-items: center; gap: 12px;
  padding: 12px 14px;
  border-radius: var(--radius-md);
  border: 1px solid var(--line);
  background: white;
  font: inherit;
  font-size: 0.97rem;
  color: var(--ink);
  text-align: left;
  cursor: pointer;
  transition: all 120ms ease;
  width: 100%;
}
.tlp-ms-option:hover:not(.is-locked) {
  background: rgba(52,168,146,0.06);
  border-color: rgba(52,168,146,0.40);
}
.tlp-ms-option.is-selected {
  background: rgba(52,168,146,0.10);
  border-color: rgba(52,168,146,0.45);
}
.tlp-ms-option.is-correct {
  background: rgba(52,168,146,0.16);
  border-color: rgba(52,168,146,0.55);
}
.tlp-ms-option.is-incorrect {
  background: rgba(184,90,70,0.10);
  border-color: rgba(184,90,70,0.45);
}
.tlp-ms-option.is-locked { cursor: default; }
.tlp-ms-option-check {
  width: 22px; height: 22px;
  border-radius: 6px;
  border: 2px solid var(--ink-muted);
  display: grid; place-items: center;
  flex-shrink: 0;
  background: white;
  color: white;
}
.tlp-ms-option.is-selected .tlp-ms-option-check,
.tlp-ms-option.is-correct  .tlp-ms-option-check {
  background: var(--teal-deep);
  border-color: var(--teal-deep);
}
.tlp-ms-option-check svg { width: 14px; height: 14px; opacity: 0; }
.tlp-ms-option.is-selected .tlp-ms-option-check svg,
.tlp-ms-option.is-correct  .tlp-ms-option-check svg { opacity: 1; }
.tlp-ms-actions { margin-top: 10px; }

/* ─── 9. Tap reveal ───────────────────────────────────────── */

.tlp-tr-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
  gap: 10px;
  margin-top: 14px;
}
.tlp-tr-tile {
  padding: 14px;
  border-radius: var(--radius-md);
  border: 1px solid var(--line);
  background: white;
  text-align: left;
  font: inherit;
  cursor: pointer;
  transition: all 140ms ease;
  display: grid;
  gap: 6px;
}
.tlp-tr-tile:hover:not(.is-revealed) {
  background: rgba(52,168,146,0.06);
  border-color: rgba(52,168,146,0.40);
  transform: translateY(-2px);
}
.tlp-tr-tile-label {
  font-weight: 700; color: var(--ink);
  font-size: 0.97rem;
}
.tlp-tr-tile-detail {
  color: var(--ink-soft);
  font-size: 0.85rem;
  line-height: 1.45;
  display: none;
}
.tlp-tr-tile.is-revealed {
  background: rgba(52,168,146,0.10);
  border-color: rgba(52,168,146,0.45);
  cursor: default;
}
.tlp-tr-tile.is-revealed .tlp-tr-tile-detail { display: block; }
.tlp-tr-hint {
  margin: 8px 0 0;
  font-size: 0.85rem;
  color: var(--ink-muted);
}

/* ─── 10. App-only fallback for harder interactives ─────── */

.tlp-app-only {
  margin-top: 14px;
  padding: 14px 16px;
  border-radius: var(--radius-md);
  background: rgba(52,168,146,0.08);
  border: 1px dashed rgba(52,168,146,0.32);
  color: var(--ink-soft);
  font-size: 0.93rem;
  line-height: 1.5;
}
.tlp-app-only strong { color: var(--ink); }

/* ─── 11. Citations footer ────────────────────────────────── */

.tlp-citations {
  margin-top: 8px;
  padding: 22px 24px;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
}
.tlp-citations-title {
  margin: 0 0 12px;
  font-size: 0.9rem;
  font-weight: 700;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  color: var(--ink-muted);
}
.tlp-citations-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 8px;
  counter-reset: tlp-cite;
}
.tlp-citations-list li {
  display: grid;
  grid-template-columns: 28px 1fr;
  gap: 8px;
  font-size: 0.88rem;
  color: var(--ink-soft);
  line-height: 1.45;
  counter-increment: tlp-cite;
}
.tlp-citations-list li::before {
  content: counter(tlp-cite) ".";
  color: var(--ink-muted);
  font-variant-numeric: tabular-nums;
}
.tlp-citations-list a {
  color: var(--teal-deep);
  text-decoration: none;
  font-weight: 600;
}
.tlp-citations-list a:hover { text-decoration: underline; }
.tlp-citations-list .tlp-cite-meta {
  color: var(--ink-muted);
  font-size: 0.82rem;
  margin-top: 2px;
}

/* ─── 12. Mark-as-complete + next-lesson CTA ──────────────── */

.tlp-complete {
  margin-top: 8px;
  padding: 22px 24px;
  background: var(--surface-strong);
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  display: grid;
  gap: 12px;
}
.tlp-complete-status {
  font-size: 0.95rem;
  color: var(--ink-soft);
  line-height: 1.5;
}
.tlp-complete-status strong { color: var(--ink); }
.tlp-complete-status .tlp-status-dot {
  display: inline-block;
  width: 8px; height: 8px;
  border-radius: 50%;
  background: var(--ink-muted);
  margin-right: 8px;
}
.tlp-complete-status.is-complete .tlp-status-dot {
  background: var(--teal-deep);
  box-shadow: 0 0 0 4px rgba(52,168,146,0.20);
}
.tlp-complete-actions {
  display: flex; flex-wrap: wrap; gap: 10px;
}
.tlp-complete-button {
  padding: 12px 22px;
  border-radius: var(--radius-md);
  border: 1px solid var(--teal-deep);
  background: var(--teal-deep);
  color: white;
  font: inherit;
  font-weight: 600;
  font-size: 0.97rem;
  cursor: pointer;
  transition: all 120ms ease;
}
.tlp-complete-button:hover:not([disabled]) {
  background: #2a8973;
  border-color: #2a8973;
}
.tlp-complete-button[disabled] { opacity: 0.7; cursor: default; }
.tlp-complete-button.is-secondary {
  background: white;
  color: var(--teal-deep);
}
.tlp-signin-hint {
  font-size: 0.85rem;
  color: var(--ink-muted);
  line-height: 1.45;
}
.tlp-signin-hint a {
  color: var(--teal-deep);
  font-weight: 600;
  text-decoration: none;
}
.tlp-signin-hint a:hover { text-decoration: underline; }

/* ─── 13. Up next + related tracks ────────────────────────── */

.tlp-upnext {
  margin-top: 8px;
  padding: 22px 24px;
  background: linear-gradient(180deg, rgba(255,255,255,0.95) 0%, rgba(244,252,248,0.85) 100%);
  border: 1px solid rgba(52,168,146,0.20);
  border-radius: var(--radius-lg);
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 14px;
  align-items: center;
  text-decoration: none;
  color: inherit;
  transition: all 140ms ease;
}
.tlp-upnext:hover {
  border-color: rgba(52,168,146,0.45);
  transform: translateY(-2px);
  box-shadow: var(--shadow-panel);
}
.tlp-upnext-eyebrow {
  font-size: 0.7rem;
  font-weight: 700;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--teal-deep);
}
.tlp-upnext-title {
  margin: 4px 0 0;
  font-size: 1.05rem;
  font-weight: 650;
  color: var(--ink);
  line-height: 1.3;
}
.tlp-upnext-arrow {
  width: 22px; height: 22px;
  color: var(--teal-deep);
  flex-shrink: 0;
}

.tlp-related {
  margin-top: 30px;
}
.tlp-related-title {
  margin: 0 0 14px;
  font-size: 0.9rem;
  font-weight: 700;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  color: var(--ink-muted);
}
.tlp-related-grid {
  display: grid;
  gap: 10px;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
}
.tlp-related-card {
  padding: 14px 16px;
  border-radius: var(--radius-md);
  background: var(--surface-strong);
  border: 1px solid var(--line);
  text-decoration: none;
  display: grid;
  grid-template-columns: auto 1fr;
  gap: 10px;
  align-items: center;
  transition: all 140ms ease;
}
.tlp-related-card:hover {
  border-color: rgba(52,168,146,0.35);
  transform: translateY(-2px);
}
.tlp-related-emoji {
  width: 36px; height: 36px;
  display: grid; place-items: center;
  font-size: 20px;
  background: rgba(52,168,146,0.10);
  border-radius: var(--radius-md);
}
.tlp-related-name {
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--ink);
}
.tlp-related-stats {
  font-size: 0.78rem;
  color: var(--ink-muted);
  margin-top: 1px;
}

.tlp-footer {
  margin: 36px auto 0;
  max-width: 720px;
  padding: 0 1.25rem;
  text-align: center;
  color: var(--ink-muted);
  font-size: 0.85rem;
}
.tlp-footer a { color: var(--teal-deep); text-decoration: none; font-weight: 600; }
.tlp-footer a:hover { text-decoration: underline; }