/* ════════════════════════════════════════════════════
   LESSON LIBRARY — Premium course catalog UI
   Hebrew RTL · Glass-3D · Apple-spring · 2025
════════════════════════════════════════════════════ */

.lesson-library {
  /* Spacing scale */
  --lib-s-1: 4px;
  --lib-s-2: 8px;
  --lib-s-3: 12px;
  --lib-s-4: 16px;
  --lib-s-5: 24px;
  --lib-s-6: 32px;
  --lib-s-7: 48px;
  /* Radius */
  --lib-r-sm: 10px;
  --lib-r-md: 16px;
  --lib-r-lg: 24px;
  /* Motion */
  --lib-ease: cubic-bezier(0.32, 0.72, 0, 1);
  --lib-spring: cubic-bezier(0.16, 1.36, 0.49, 1);
  --lib-dur: 320ms;
  --lib-ring: 0 0 0 3px color-mix(in oklab, var(--accent) 50%, transparent);
  /* Surface */
  --lib-surface: rgba(14, 14, 22, 0.55);
  --lib-surface-2: rgba(20, 20, 30, 0.85);
  --lib-stroke: rgba(255, 255, 255, 0.07);
  --lib-stroke-2: rgba(255, 255, 255, 0.12);
  /* Default accent */
  --accent: #E8A020;

  max-width: 1240px;
  margin: 1.5rem auto 5rem;
  padding: 0 1.25rem;
  position: relative;
}

/* ── Ambient orb glow behind library ───────────── */
.lesson-library::before {
  content: '';
  position: absolute;
  inset: -10% 10% auto 10%;
  height: 320px;
  background: radial-gradient(
    ellipse at 30% 50%,
    rgba(232, 160, 32, 0.08),
    rgba(139, 92, 246, 0.06) 30%,
    transparent 70%
  );
  filter: blur(80px);
  z-index: -1;
  pointer-events: none;
}

/* ── Header ──────────────────────────────────────── */
.lib-header {
  margin-bottom: var(--lib-s-5);
  text-align: start;
}
.lib-title {
  font-size: clamp(1.6rem, 3vw, 2.2rem);
  font-weight: 900;
  letter-spacing: -0.02em;
  line-height: 1.1;
  margin: 0 0 var(--lib-s-2);
  background: linear-gradient(
    135deg,
    #FFE9A6 0%,
    #FAD261 20%,
    #E8A020 50%,
    #C56DC4 90%
  );
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  filter: drop-shadow(0 2px 12px rgba(232, 160, 32, 0.25));
}
.lib-subtitle {
  font-size: 0.95rem;
  color: rgba(240, 240, 255, 0.55);
  margin: 0;
}
.lib-subtitle bdi {
  font-weight: 800;
  color: rgba(255, 255, 255, 0.92);
  font-family: 'Space Grotesk', monospace;
  letter-spacing: -0.01em;
}

/* ── Sticky controls bar (glass) ─────────────────── */
.lib-controls {
  position: sticky;
  top: 80px;
  z-index: 10;
  display: flex;
  gap: var(--lib-s-3);
  flex-wrap: wrap;
  align-items: center;
  padding: var(--lib-s-3) var(--lib-s-4);
  margin-bottom: var(--lib-s-6);
  background: linear-gradient(
    135deg,
    rgba(20, 20, 30, 0.78) 0%,
    rgba(14, 14, 22, 0.72) 100%
  );
  backdrop-filter: blur(20px) saturate(180%);
  -webkit-backdrop-filter: blur(20px) saturate(180%);
  border: 1px solid rgba(255, 255, 255, 0.08);
  border-radius: var(--lib-r-md);
  box-shadow:
    0 1px 0 rgba(255, 255, 255, 0.05) inset,
    0 12px 40px -12px rgba(0, 0, 0, 0.55);
}
.lib-search {
  flex: 1 1 280px;
  min-height: 44px;
  padding: 0.75rem 1.1rem;
  border-radius: var(--lib-r-sm);
  background: rgba(0, 0, 0, 0.35);
  border: 1px solid rgba(255, 255, 255, 0.08);
  color: rgba(240, 240, 255, 0.95);
  font: inherit;
  font-size: 0.95rem;
  font-weight: 500;
  direction: rtl;
  transition: border-color var(--lib-dur) var(--lib-ease),
              box-shadow var(--lib-dur) var(--lib-ease);
}
.lib-search::placeholder { color: rgba(240, 240, 255, 0.35); }
.lib-search:focus {
  outline: none;
  border-color: rgba(232, 160, 32, 0.5);
  box-shadow: 0 0 0 4px rgba(232, 160, 32, 0.15);
}
/* ── Focus visible (a11y H-26: ≥3:1 contrast indicator) ───────────────────── */
.lib-search:focus-visible,
.lib-filter-pill:focus-visible,
.lib-group__header:focus-visible,
.lib-lesson:focus-visible,
.lib-lesson__cta:focus-visible,
.lib-lesson__title:focus-visible {
  outline: 2px solid #00C4B3;
  outline-offset: 2px;
  box-shadow: 0 0 0 3px rgba(0,196,179,0.25);
}
.lib-filters {
  display: flex;
  gap: var(--lib-s-2);
  flex-wrap: wrap;
}
.lib-filter-pill {
  position: relative;
  min-height: 40px;
  padding: 0.5rem 1.15rem;
  border-radius: 999px;
  border: 1px solid rgba(255, 255, 255, 0.1);
  background: rgba(255, 255, 255, 0.025);
  color: rgba(240, 240, 255, 0.65);
  font: inherit;
  font-weight: 700;
  font-size: 0.86rem;
  cursor: pointer;
  transition: all var(--lib-dur) var(--lib-ease);
}
.lib-filter-pill:hover {
  background: rgba(255, 255, 255, 0.06);
  color: rgba(240, 240, 255, 0.95);
  transform: translateY(-1px);
}
.lib-filter-pill.active {
  background: linear-gradient(135deg, #E8A020 0%, #C56DC4 100%);
  border-color: transparent;
  color: #1a0d00;
  font-weight: 800;
  box-shadow:
    0 4px 16px -4px rgba(232, 160, 32, 0.5),
    0 1px 0 rgba(255, 255, 255, 0.3) inset;
}
.lib-filter-pill:focus-visible {
  outline: none;
  box-shadow: 0 0 0 3px rgba(232, 160, 32, 0.5);
}

/* ── Groups stack ──────────────────────────────── */
.lib-groups {
  display: grid;
  gap: var(--lib-s-5);
}

/* ── Group card (premium glass tile) ───────────── */
.lib-group {
  position: relative;
  border-radius: var(--lib-r-lg);
  background: linear-gradient(
    180deg,
    color-mix(in oklab, var(--accent) 8%, var(--lib-surface)) 0%,
    var(--lib-surface) 35%,
    var(--lib-surface) 100%
  );
  border: 1px solid color-mix(in oklab, var(--accent) 18%, var(--lib-stroke));
  box-shadow:
    0 1px 0 rgba(255, 255, 255, 0.06) inset,
    0 24px 60px -28px color-mix(in oklab, var(--accent) 25%, transparent),
    0 4px 20px -8px rgba(0, 0, 0, 0.4);
  overflow: hidden;
  transition: transform var(--lib-dur) var(--lib-ease),
              box-shadow var(--lib-dur) var(--lib-ease),
              border-color var(--lib-dur) var(--lib-ease);
}
/* Decorative corner accent */
.lib-group::before {
  content: '';
  position: absolute;
  top: 0;
  inset-inline-start: 0;
  width: 60%;
  height: 200px;
  background: radial-gradient(
    ellipse at top start,
    color-mix(in oklab, var(--accent) 25%, transparent),
    transparent 60%
  );
  pointer-events: none;
  opacity: 0.6;
  transition: opacity var(--lib-dur) var(--lib-ease);
}
.lib-group:hover {
  border-color: color-mix(in oklab, var(--accent) 35%, var(--lib-stroke));
}
.lib-group:hover::before { opacity: 1; }

/* ── Group header ─────────────────────────────── */
.lib-group__header {
  display: grid;
  grid-template-areas: "icon title chev" "icon meta progress";
  grid-template-columns: 72px 1fr auto;
  grid-template-rows: auto auto;
  gap: var(--lib-s-2) var(--lib-s-4);
  align-items: center;
  padding: var(--lib-s-5) var(--lib-s-5);
  cursor: pointer;
  list-style: none;
  position: relative;
}
.lib-group__header::-webkit-details-marker { display: none; }
.lib-group__header::marker { content: ''; }
.lib-group__header:focus-visible {
  outline: none;
  box-shadow: var(--lib-ring);
  border-radius: var(--lib-r-lg);
}

.lib-group__icon {
  grid-area: icon;
  display: grid;
  place-items: center;
  width: 64px;
  height: 64px;
  border-radius: 18px;
  font-size: 1.85rem;
  background: linear-gradient(
    135deg,
    color-mix(in oklab, var(--accent) 30%, transparent) 0%,
    color-mix(in oklab, var(--accent) 12%, var(--lib-surface-2)) 100%
  );
  border: 1px solid color-mix(in oklab, var(--accent) 30%, var(--lib-stroke-2));
  box-shadow:
    0 1px 0 rgba(255, 255, 255, 0.15) inset,
    0 8px 24px -8px color-mix(in oklab, var(--accent) 40%, transparent);
  transition: transform var(--lib-dur) var(--lib-spring);
}
.lib-group:hover .lib-group__icon {
  transform: scale(1.06) rotate(-3deg);
}

.lib-group__label {
  grid-area: title;
  font-size: 1.4rem;
  font-weight: 900;
  letter-spacing: -0.02em;
  color: rgba(255, 255, 255, 0.96);
  margin: 0;
}

.lib-group__meta {
  grid-area: meta;
  font-size: 0.86rem;
  color: rgba(240, 240, 255, 0.55);
  font-weight: 600;
}

.lib-group__progress {
  grid-area: progress;
  display: flex;
  align-items: center;
  gap: var(--lib-s-2);
  padding: 0.4rem 0.85rem;
  border-radius: 999px;
  background: rgba(0, 0, 0, 0.35);
  border: 1px solid var(--lib-stroke);
}
.lib-progress-bar {
  display: block;
  width: 90px;
  height: 5px;
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.08);
  overflow: hidden;
  direction: rtl;
}
.lib-progress-fill {
  display: block;
  height: 100%;
  background: linear-gradient(
    90deg,
    var(--accent) 0%,
    color-mix(in oklab, var(--accent) 70%, white) 100%
  );
  border-radius: 999px;
  box-shadow: 0 0 12px color-mix(in oklab, var(--accent) 60%, transparent);
  transition: width 900ms var(--lib-ease);
}
.lib-progress-text {
  font-family: 'Space Grotesk', monospace;
  font-size: 0.78rem;
  font-weight: 800;
  color: rgba(255, 255, 255, 0.9);
  letter-spacing: -0.01em;
  white-space: nowrap;
}

.lib-group__chev {
  grid-area: chev;
  display: grid;
  place-items: center;
  width: 36px;
  height: 36px;
  border-radius: 12px;
  font-size: 1rem;
  color: var(--accent);
  background: color-mix(in oklab, var(--accent) 12%, transparent);
  border: 1px solid color-mix(in oklab, var(--accent) 25%, transparent);
  transform: rotate(-90deg);
  transition: transform var(--lib-dur) var(--lib-spring),
              background var(--lib-dur) var(--lib-ease);
}
.lib-group[open] .lib-group__chev {
  transform: rotate(0deg);
  background: color-mix(in oklab, var(--accent) 22%, transparent);
}

/* ── Group body (lessons grid) ───────────────────── */
.lib-group__body {
  padding: 0 var(--lib-s-4) var(--lib-s-4);
}
.lib-group[open] > .lib-group__body {
  animation: libGroupFadeIn 380ms var(--lib-ease);
}
@keyframes libGroupFadeIn {
  from { opacity: 0; transform: translateY(-6px); }
  to { opacity: 1; transform: translateY(0); }
}

.lib-group__lessons {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: var(--lib-s-3);
}

/* ── Lesson card (premium row) ───────────────────── */
.lib-lesson {
  position: relative;
  display: grid;
  grid-template-areas:
    "id    body  meta cta"
    "state body  meta cta";
  grid-template-columns: 56px 1fr auto auto;
  grid-template-rows: auto auto;
  gap: var(--lib-s-1) var(--lib-s-4);
  align-items: center;
  padding: var(--lib-s-4) var(--lib-s-5);
  min-height: 72px;
  border-radius: var(--lib-r-md);
  background: linear-gradient(
    180deg,
    rgba(255, 255, 255, 0.025) 0%,
    rgba(255, 255, 255, 0.015) 100%
  );
  border: 1px solid var(--lib-stroke);
  overflow: hidden;
  isolation: isolate;
  transition: transform var(--lib-dur) var(--lib-spring),
              border-color var(--lib-dur) var(--lib-ease),
              background var(--lib-dur) var(--lib-ease),
              box-shadow var(--lib-dur) var(--lib-ease);
}
/* Side accent bar (RTL: right edge) */
.lib-lesson::before {
  content: '';
  position: absolute;
  inset: 0 auto 0 0;
  width: 3px;
  background: linear-gradient(
    180deg,
    var(--accent) 0%,
    color-mix(in oklab, var(--accent) 70%, white) 100%
  );
  opacity: 0;
  transition: opacity var(--lib-dur) var(--lib-ease);
  z-index: 0;
}
.lib-lesson:hover:not(.lib-lesson--locked) {
  transform: translateX(-4px) translateY(-1px);
  background: linear-gradient(
    135deg,
    color-mix(in oklab, var(--accent) 8%, rgba(255, 255, 255, 0.025)) 0%,
    rgba(255, 255, 255, 0.015) 100%
  );
  border-color: color-mix(in oklab, var(--accent) 35%, var(--lib-stroke));
  box-shadow:
    0 12px 32px -10px color-mix(in oklab, var(--accent) 35%, transparent),
    0 1px 0 rgba(255, 255, 255, 0.07) inset;
}
.lib-lesson:hover:not(.lib-lesson--locked)::before { opacity: 1; }
.lib-lesson:focus-within:not(.lib-lesson--locked) {
  box-shadow: 0 0 0 3px rgba(232, 160, 32, 0.4);
}

/* Done state */
.lib-lesson--done {
  border-color: rgba(16, 185, 129, 0.28);
  background: linear-gradient(
    135deg,
    rgba(16, 185, 129, 0.06) 0%,
    rgba(16, 185, 129, 0.02) 100%
  );
}
.lib-lesson--done::before {
  background: linear-gradient(180deg, #10B981 0%, #34D399 100%);
  opacity: 1;
}
.lib-lesson--done .lib-lesson__title {
  color: rgba(255, 255, 255, 0.78);
}
.lib-lesson--done .lib-lesson__state {
  background: rgba(16, 185, 129, 0.18);
  border-color: rgba(16, 185, 129, 0.4);
  color: #34D399;
}

/* Locked state */
.lib-lesson--locked {
  cursor: not-allowed;
  opacity: 0.78;
  filter: saturate(0.65);
}
.lib-lesson--locked::before {
  background: linear-gradient(180deg, #F59E0B 0%, #FCD34D 100%);
  opacity: 0.5;
}
.lib-lesson--locked .lib-lesson__state {
  background: rgba(245, 158, 11, 0.15);
  border-color: rgba(245, 158, 11, 0.35);
  color: #FCD34D;
}
.lib-lesson--locked .lib-lesson__cta {
  background: linear-gradient(135deg, rgba(245, 158, 11, 0.18) 0%, rgba(245, 158, 11, 0.08) 100%);
  border-color: rgba(245, 158, 11, 0.35);
  color: #FCD34D;
}
.lib-lesson--locked:hover .lib-lesson__cta {
  background: linear-gradient(135deg, #F59E0B 0%, #FCD34D 100%);
  color: #2a1900;
  transform: scale(1.04);
}

/* Card cells */
.lib-lesson__id {
  grid-area: id;
  font-family: 'Space Grotesk', monospace;
  font-size: 1.1rem;
  font-weight: 800;
  color: rgba(240, 240, 255, 0.35);
  text-align: center;
  letter-spacing: -0.02em;
  align-self: start;
  padding-top: 4px;
}
.lib-lesson--done .lib-lesson__id { color: rgba(16, 185, 129, 0.6); }

.lib-lesson__state {
  grid-area: state;
  display: grid;
  place-items: center;
  width: 32px;
  height: 32px;
  margin-inline-start: 12px;
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.04);
  border: 1px solid rgba(255, 255, 255, 0.08);
  font-size: 0.95rem;
  color: rgba(240, 240, 255, 0.45);
  align-self: end;
}

.lib-lesson__body {
  grid-area: body;
  min-width: 0;
  display: flex;
  flex-direction: column;
  gap: 4px;
}
.lib-lesson__title {
  font-size: 1.04rem;
  font-weight: 700;
  color: rgba(255, 255, 255, 0.95);
  line-height: 1.35;
  margin: 0;
  letter-spacing: -0.01em;
  display: -webkit-box;
  -webkit-line-clamp: 1;
  -webkit-box-orient: vertical;
  overflow: hidden;
}
.lib-lesson__desc {
  font-size: 0.84rem;
  color: rgba(240, 240, 255, 0.5);
  line-height: 1.5;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
  margin: 0;
}

.lib-lesson__meta {
  grid-area: meta;
  display: flex;
  flex-direction: column;
  align-items: flex-end;
  gap: 4px;
  font-size: 0.78rem;
  color: rgba(240, 240, 255, 0.5);
  white-space: nowrap;
}
.lib-lesson__badge {
  padding: 2px 9px;
  border-radius: 999px;
  background: color-mix(in oklab, var(--accent) 14%, transparent);
  border: 1px solid color-mix(in oklab, var(--accent) 25%, transparent);
  color: rgba(255, 255, 255, 0.85);
  font-size: 0.74rem;
  font-weight: 700;
}
.lib-lesson__duration {
  font-family: 'Space Grotesk', monospace;
  letter-spacing: 0.02em;
  font-weight: 600;
}

.lib-lesson__cta {
  grid-area: cta;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  min-height: 42px;
  padding: 0.55rem 1.15rem;
  border-radius: var(--lib-r-sm);
  background: linear-gradient(
    135deg,
    color-mix(in oklab, var(--accent) 22%, transparent) 0%,
    color-mix(in oklab, var(--accent) 10%, transparent) 100%
  );
  border: 1px solid color-mix(in oklab, var(--accent) 35%, transparent);
  color: rgba(255, 255, 255, 0.95);
  font-weight: 800;
  font-size: 0.86rem;
  text-decoration: none;
  white-space: nowrap;
  transition: all var(--lib-dur) var(--lib-spring);
  align-self: center;
}
.lib-lesson__cta:hover {
  background: linear-gradient(
    135deg,
    var(--accent) 0%,
    color-mix(in oklab, var(--accent) 70%, white) 100%
  );
  color: #1a0d00;
  border-color: transparent;
  transform: scale(1.04);
  box-shadow: 0 6px 20px -4px color-mix(in oklab, var(--accent) 50%, transparent);
}
.lib-lesson__cta:focus-visible {
  outline: none;
  box-shadow: 0 0 0 3px color-mix(in oklab, var(--accent) 50%, transparent);
}

/* Hidden by filter/search */
.lib-hidden { display: none !important; }

/* Empty state */
.lib-group__empty {
  text-align: center;
  padding: var(--lib-s-7) var(--lib-s-5);
  color: rgba(240, 240, 255, 0.55);
  display: grid;
  place-items: center;
  gap: var(--lib-s-2);
}
.lib-empty-icon {
  font-size: 2rem;
  width: 64px;
  height: 64px;
  display: grid;
  place-items: center;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.04);
  border: 1px solid var(--lib-stroke);
}
.lib-group__empty p { margin: 0; font-size: 0.95rem; font-weight: 600; }

/* ── Mobile (<720px) ─────────────────────────────── */
@media (max-width: 720px) {
  .lesson-library { padding: 0 1rem; margin-bottom: 3rem; }
  .lib-controls {
    position: static;
    padding: var(--lib-s-2);
  }
  .lib-filters {
    flex-wrap: nowrap;
    overflow-x: auto;
    scrollbar-width: none;
    width: 100%;
    -webkit-overflow-scrolling: touch;
    padding-bottom: 2px;
  }
  .lib-filters::-webkit-scrollbar { display: none; }
  .lib-filter-pill { flex-shrink: 0; min-height: 44px; }

  .lib-group__header {
    grid-template-areas:
      "icon title chev"
      "icon meta chev"
      "progress progress progress";
    grid-template-columns: 56px 1fr 36px;
    grid-template-rows: auto auto auto;
    padding: var(--lib-s-4);
    gap: var(--lib-s-1) var(--lib-s-3);
  }
  .lib-group__icon { width: 56px; height: 56px; font-size: 1.5rem; }
  .lib-group__label { font-size: 1.15rem; }
  .lib-group__progress { justify-self: stretch; margin-top: var(--lib-s-2); }
  .lib-progress-bar { width: 100%; max-width: none; flex: 1; }

  .lib-lesson {
    grid-template-areas:
      "id    body"
      "state body"
      "meta  cta";
    grid-template-columns: 36px 1fr;
    padding: var(--lib-s-3);
    gap: var(--lib-s-1) var(--lib-s-3);
  }
  .lib-lesson__id { font-size: 0.9rem; padding-top: 0; }
  .lib-lesson__state { width: 26px; height: 26px; margin-inline-start: 4px; font-size: 0.85rem; }
  .lib-lesson__title { font-size: 0.96rem; }
  .lib-lesson__desc { display: none; }
  .lib-lesson__meta {
    flex-direction: row;
    align-items: center;
    justify-content: flex-start;
    margin-top: var(--lib-s-2);
  }
  .lib-lesson__cta { min-height: 44px; justify-self: end; }
}

/* ── Reduced motion ──────────────────────────────── */
@media (prefers-reduced-motion: reduce) {
  .lib-group__chev,
  .lib-group__icon,
  .lib-lesson,
  .lib-lesson::before,
  .lib-progress-fill,
  .lib-filter-pill,
  .lib-lesson__cta,
  .lib-group[open] > .lib-group__body { transition: none; animation: none; }
  .lib-lesson:hover { transform: none; }
}

/* CLS fix — reserve space while lesson grid loads */
.lessons-grid:empty {
  min-height: 800px;
  display: block;
}
.lesson-library:has(.lessons-grid:empty) .lib-subtitle::after {
  content: " ⏳";
  opacity: 0.6;
}