/* ===========================================================================
   Mavzu sahifasi: sarlavha, o'qish muhiti, PDF viewer, nazorat, adabiyot
   sytle.txt §8, §9 - "digital learning environment", "kitob o'qiyotgandek"
   =========================================================================== */

/* --- Mavzu sarlavhasi ----------------------------------------------------- */

.topic-header {
  padding: var(--s-6) 0 var(--s-5);
  border-bottom: 1px solid var(--border);
  margin-bottom: var(--s-6);
}

.topic-header__label {
  display: inline-flex;
  align-items: center;
  gap: var(--s-2);
  font-family: var(--font-display);
  font-size: var(--fs-xs);
  font-weight: 700;
  letter-spacing: var(--tracking-wide);
  text-transform: uppercase;
  color: var(--brand-600);
  margin-bottom: var(--s-2);
}

.topic-header__title {
  font-size: clamp(var(--fs-xl), 3vw, var(--fs-2xl));
  max-width: 42ch;
}

.topic-header__meta {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: var(--s-4);
  margin-top: var(--s-4);
}

.topic-progress {
  display: flex;
  align-items: center;
  gap: var(--s-3);
  min-width: 200px;
}

.topic-progress .progress {
  flex: 1;
  min-width: 90px;
}

.topic-progress__text {
  font-size: var(--fs-xs);
  font-weight: 600;
  color: var(--text-muted);
  white-space: nowrap;
}

/* --- Material paneli ------------------------------------------------------ */

.material {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  overflow: hidden;
}

.material__bar {
  display: flex;
  align-items: center;
  gap: var(--s-3);
  flex-wrap: wrap;
  padding: var(--s-4) var(--s-5);
  border-bottom: 1px solid var(--border);
  background: var(--surface-2);
}

.material__title {
  font-family: var(--font-display);
  font-size: var(--fs-md);
  font-weight: 700;
  color: var(--ink-900);
}

.material__actions {
  display: flex;
  align-items: center;
  gap: var(--s-2);
  margin-left: auto;
}

.material__body {
  padding: var(--s-8);
}

.material__body--flush {
  padding: 0;
}

@media (max-width: 640px) {
  .material__body {
    padding: var(--s-5);
  }

  .material__bar {
    padding: var(--s-3) var(--s-4);
  }

  .material__actions {
    width: 100%;
    margin-left: 0;
  }
}

/* --- O'qish muhiti (ma'ruza matni) ---------------------------------------- */

.reader {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 210px;
  gap: var(--s-8);
  align-items: start;
}

.reader__content {
  max-width: var(--measure);
  font-size: var(--fs-md);
  line-height: var(--lh-relaxed);
  color: var(--ink-700);
}

.reader__content > * + * {
  margin-top: var(--s-5);
}

.reader__content p {
  text-align: justify;
  hyphens: auto;
}

.lesson-heading {
  font-size: var(--fs-xl);
  color: var(--ink-900);
  margin-top: var(--s-10) !important;
  padding-top: var(--s-2);
  scroll-margin-top: calc(var(--header-h) + var(--s-6));
}

.lesson-heading:first-child {
  margin-top: 0 !important;
}

.lesson-subheading {
  font-size: var(--fs-md);
  color: var(--ink-800);
  margin-top: var(--s-7) !important;
}

.lesson-list {
  padding-left: var(--s-5);
}

.lesson-list li + li {
  margin-top: var(--s-2);
}

.lesson-figure {
  margin: var(--s-6) 0;
  padding: var(--s-3);
  background: var(--surface-2);
  border: 1px solid var(--border);
  border-radius: var(--radius);
}

.lesson-figure img {
  margin-inline: auto;
  border-radius: var(--radius-xs);
}

/* Reja bloki */
.lesson-plan {
  padding: var(--s-5) var(--s-6);
  background: var(--brand-50);
  border: 1px solid var(--brand-100);
  border-radius: var(--radius);
}

.lesson-plan__title {
  font-family: var(--font-display);
  font-size: var(--fs-xs);
  font-weight: 700;
  letter-spacing: var(--tracking-wide);
  text-transform: uppercase;
  color: var(--brand-700);
  margin-bottom: var(--s-3);
}

.lesson-plan ol {
  margin: 0;
  padding-left: var(--s-5);
  font-size: var(--fs-sm);
  line-height: 1.7;
  color: var(--ink-700);
}

.lesson-plan li + li {
  margin-top: var(--s-2);
}

/* Ichki navigatsiya (Reja bo'yicha) */
.reader__toc {
  position: sticky;
  top: calc(var(--header-h-compact) + var(--s-5));
  font-size: var(--fs-xs);
}

.reader__toc-title {
  font-family: var(--font-display);
  font-weight: 700;
  letter-spacing: var(--tracking-wide);
  text-transform: uppercase;
  color: var(--text-subtle);
  margin-bottom: var(--s-3);
}

.reader__toc ol {
  list-style: none;
  padding: 0;
  border-left: 2px solid var(--border);
  display: flex;
  flex-direction: column;
}

.reader__toc a {
  display: block;
  padding: var(--s-2) var(--s-3);
  margin-left: -2px;
  border-left: 2px solid transparent;
  color: var(--text-muted);
  line-height: 1.5;
  transition: color var(--dur-fast) var(--ease), border-color var(--dur-fast) var(--ease);
}

.reader__toc a:hover {
  color: var(--ink-900);
}

.reader__toc a.is-active {
  color: var(--brand-700);
  border-left-color: var(--brand-600);
  font-weight: 600;
}

@media (max-width: 1200px) {
  .reader {
    grid-template-columns: 1fr;
  }

  .reader__toc {
    display: none;
  }
}

/* --- PDF viewer (sytle.txt §9) -------------------------------------------- */

.pdf-viewer {
  display: grid;
  grid-template-columns: 160px minmax(0, 1fr);
  height: min(78vh, 900px);
  background: var(--ink-100);
}

.pdf-viewer__rail {
  overflow-y: auto;
  padding: var(--s-3);
  background: var(--surface-2);
  border-right: 1px solid var(--border);
  display: flex;
  flex-direction: column;
  gap: var(--s-3);
}

.pdf-thumb {
  border: 2px solid transparent;
  border-radius: var(--radius-xs);
  overflow: hidden;
  background: #fff;
  box-shadow: var(--shadow-xs);
  transition: border-color var(--dur-fast) var(--ease);
  position: relative;
}

.pdf-thumb:hover {
  border-color: var(--brand-300);
}

.pdf-thumb.is-active {
  border-color: var(--brand-600);
}

.pdf-thumb img {
  width: 100%;
  display: block;
}

.pdf-thumb__num {
  position: absolute;
  bottom: 4px;
  right: 4px;
  padding: 1px 6px;
  border-radius: var(--radius-full);
  background: rgba(15, 23, 42, 0.72);
  color: #fff;
  font-size: 0.65rem;
  font-weight: 600;
}

.pdf-viewer__main {
  display: flex;
  flex-direction: column;
  min-width: 0;
}

.pdf-toolbar {
  display: flex;
  align-items: center;
  gap: var(--s-2);
  padding: var(--s-2) var(--s-3);
  background: var(--surface);
  border-bottom: 1px solid var(--border);
  flex-wrap: wrap;
}

.pdf-toolbar__group {
  display: flex;
  align-items: center;
  gap: var(--s-1);
}

.pdf-toolbar__btn {
  width: 34px;
  height: 34px;
  display: grid;
  place-items: center;
  border-radius: var(--radius-xs);
  color: var(--ink-600);
  transition: background var(--dur-fast) var(--ease), color var(--dur-fast) var(--ease);
}

.pdf-toolbar__btn:hover:not(:disabled) {
  background: var(--surface-2);
  color: var(--ink-900);
}

.pdf-toolbar__btn:disabled {
  opacity: 0.35;
  cursor: default;
}

.pdf-toolbar__btn svg {
  width: 18px;
  height: 18px;
}

.pdf-pageinput {
  width: 48px;
  padding: 0.3rem;
  text-align: center;
  font-size: var(--fs-xs);
  font-weight: 600;
  border: 1px solid var(--border-strong);
  border-radius: var(--radius-xs);
}

.pdf-toolbar__count {
  font-size: var(--fs-xs);
  color: var(--text-subtle);
  white-space: nowrap;
}

.pdf-search {
  display: flex;
  align-items: center;
  gap: var(--s-2);
  margin-left: auto;
}

.pdf-search input {
  width: 170px;
  padding: 0.35rem 0.6rem;
  font-size: var(--fs-xs);
  border: 1px solid var(--border-strong);
  border-radius: var(--radius-xs);
}

.pdf-search input:focus {
  outline: none;
  border-color: var(--brand-500);
  box-shadow: 0 0 0 2px var(--brand-100);
}

.pdf-search__count {
  font-size: var(--fs-xs);
  color: var(--text-subtle);
  min-width: 44px;
}

.pdf-canvas-wrap {
  flex: 1;
  overflow: auto;
  padding: var(--s-5);
  display: flex;
  justify-content: center;
  align-items: flex-start;
  background: var(--ink-200);
  scroll-behavior: smooth;
  touch-action: pan-x pan-y;
}

.pdf-page {
  position: relative;
  background: #fff;
  box-shadow: var(--shadow-md);
  border-radius: 2px;
}

.pdf-page canvas {
  display: block;
  border-radius: inherit;
}

/* PDF.js matn qatlami - qidiruv va nusxalash uchun */
.pdf-text-layer {
  position: absolute;
  inset: 0;
  overflow: hidden;
  opacity: 0.24;
  line-height: 1;
  forced-color-adjust: none;
}

.pdf-text-layer span {
  position: absolute;
  white-space: pre;
  transform-origin: 0 0;
  color: transparent;
  cursor: text;
}

.pdf-text-layer ::selection {
  background: var(--brand-400);
}

.pdf-text-layer .pdf-hit {
  background: var(--warning);
  border-radius: 2px;
}

.pdf-text-layer .pdf-hit--current {
  background: var(--cyan-400);
}

.pdf-loading {
  display: grid;
  place-items: center;
  gap: var(--s-3);
  padding: var(--s-16);
  color: var(--text-muted);
  font-size: var(--fs-sm);
}

.pdf-spinner {
  width: 30px;
  height: 30px;
  border: 3px solid var(--border-strong);
  border-top-color: var(--brand-600);
  border-radius: 50%;
  animation: spin 0.7s linear infinite;
}

@keyframes spin {
  to {
    transform: rotate(360deg);
  }
}

/* To'liq ekran */
.pdf-viewer:fullscreen {
  height: 100vh;
  background: var(--ink-900);
}

@media (max-width: 900px) {
  .pdf-viewer {
    grid-template-columns: 1fr;
    height: min(72vh, 720px);
  }

  .pdf-viewer__rail {
    display: none;
  }

  .pdf-search input {
    width: 120px;
  }

  .pdf-canvas-wrap {
    padding: var(--s-3);
  }
}

/* --- Nazorat savollari ---------------------------------------------------- */

.qa-list {
  list-style: none;
  padding: 0;
  counter-reset: qa;
  display: flex;
  flex-direction: column;
  gap: var(--s-3);
  max-width: var(--measure);
}

.qa-item {
  display: flex;
  gap: var(--s-4);
  padding: var(--s-4) var(--s-5);
  background: var(--surface-2);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  font-size: var(--fs-md);
  line-height: 1.7;
  transition: border-color var(--dur-fast) var(--ease);
}

.qa-item:hover {
  border-color: var(--brand-200);
}

.qa-item__num {
  width: 30px;
  height: 30px;
  flex: none;
  display: grid;
  place-items: center;
  border-radius: 50%;
  background: var(--brand-600);
  color: #fff;
  font-family: var(--font-display);
  font-size: var(--fs-xs);
  font-weight: 700;
  margin-top: 2px;
}

/* --- Adabiyotlar ---------------------------------------------------------- */

.ref-list {
  list-style: none;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: var(--s-3);
  max-width: var(--measure);
  counter-reset: ref;
}

.ref-item {
  display: flex;
  gap: var(--s-4);
  padding-bottom: var(--s-3);
  border-bottom: 1px solid var(--border);
  font-size: var(--fs-sm);
  line-height: 1.7;
  color: var(--ink-700);
}

.ref-item:last-child {
  border-bottom: none;
}

.ref-item__num {
  flex: none;
  font-family: var(--font-display);
  font-weight: 700;
  color: var(--brand-500);
  min-width: 1.6rem;
}