/* ============================================
   Special In-App PDF Reader & Study Companion Styles
   ============================================ */

.pdf-viewer-modal {
  position: fixed;
  inset: 0;
  background: var(--clr-bg);
  z-index: calc(var(--z-modal) + 10);
  display: flex;
  flex-direction: column;
  overflow: hidden;
  animation: pdfModalFadeIn 0.2s cubic-bezier(0.16, 1, 0.3, 1);
}

@keyframes pdfModalFadeIn {
  from { opacity: 0; transform: scale(0.98); }
  to { opacity: 1; transform: scale(1); }
}

.pdf-toolbar {
  height: 56px;
  background: var(--clr-surface);
  border-bottom: 1px solid var(--clr-border);
  padding: 0 var(--sp-4);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--sp-3);
  z-index: 10;
  box-shadow: var(--shadow-sm);
}

.pdf-toolbar__left {
  display: flex;
  align-items: center;
  gap: var(--sp-3);
  min-width: 200px;
}

.pdf-title-badge {
  display: flex;
  flex-direction: column;
}

.pdf-title-badge strong {
  font-size: var(--fs-sm);
  color: var(--clr-text);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  max-width: 200px;
}

.pdf-title-badge span {
  font-size: var(--fs-xs);
  color: var(--clr-text-muted);
}

.pdf-toolbar__center {
  display: flex;
  align-items: center;
  gap: var(--sp-2);
  flex-wrap: nowrap;
}

.pdf-tool-btn {
  background: var(--clr-surface-hover);
  border: 1px solid var(--clr-border);
  border-radius: var(--radius-md);
  color: var(--clr-text);
  font-size: var(--fs-xs);
  font-weight: var(--fw-semibold);
  padding: 5px 10px;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  gap: 4px;
  transition: all var(--dur-fast);
}

.pdf-tool-btn:hover {
  background: var(--clr-cream);
  border-color: var(--clr-accent);
}

.pdf-tool-btn.is-active {
  background: var(--clr-accent);
  color: #1a1a2e;
  border-color: var(--clr-accent);
}

.pdf-divider {
  width: 1px;
  height: 22px;
  background: var(--clr-border);
  margin: 0 4px;
}

.pdf-page-indicator {
  font-size: var(--fs-xs);
  color: var(--clr-text-muted);
  display: flex;
  align-items: center;
  gap: 4px;
}

.pdf-color-picker {
  display: flex;
  align-items: center;
  gap: 6px;
  background: var(--clr-surface-hover);
  padding: 4px 8px;
  border-radius: var(--radius-full);
  border: 1px solid var(--clr-border);
}

.color-dot {
  width: 14px;
  height: 14px;
  border-radius: 50%;
  cursor: pointer;
  transition: transform var(--dur-fast);
}

.color-dot:hover {
  transform: scale(1.3);
}

.color-dot.is-active {
  box-shadow: 0 0 0 2px var(--clr-text);
}

.pdf-toolbar__right {
  display: flex;
  align-items: center;
  gap: var(--sp-2);
}

/* PDF Body & Layout */
.pdf-body {
  flex: 1;
  display: flex;
  overflow: hidden;
  position: relative;
}

.pdf-viewport-container {
  flex: 1;
  overflow: auto;
  background: #2a2a38;
  display: flex;
  justify-content: center;
  align-items: flex-start;
  padding: var(--sp-6);
  position: relative;
}

.pdf-canvas-wrapper {
  position: relative;
  box-shadow: 0 10px 40px rgba(0,0,0,0.5);
  background: #ffffff;
  border-radius: var(--radius-sm);
  transition: filter 0.3s;
}

.pdf-canvas-wrapper.filter-sepia {
  filter: sepia(0.4) contrast(0.95) brightness(0.95);
}

.pdf-canvas-wrapper.filter-dark {
  filter: invert(0.9) hue-rotate(180deg);
}

#pdfCanvas {
  display: block;
  max-width: 100%;
}

#pdfAnnotationCanvas {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  pointer-events: none;
}

/* PDF Sidebar Companion */
.pdf-study-sidebar {
  width: 340px;
  background: var(--clr-surface);
  border-left: 1px solid var(--clr-border);
  display: flex;
  flex-direction: column;
  padding: var(--sp-4);
  overflow-y: auto;
  transition: transform 0.25s cubic-bezier(0.16, 1, 0.3, 1), width 0.25s;
}

.pdf-study-sidebar.is-hidden {
  display: none;
}

.pdf-sidebar-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: var(--sp-3);
  padding-bottom: var(--sp-2);
  border-bottom: 1px solid var(--clr-border);
}

.pdf-sidebar-header h4 {
  font-size: var(--fs-sm);
  font-weight: var(--fw-bold);
  margin: 0;
}

.pdf-tool-card {
  background: var(--clr-cream);
  border: 1px solid var(--clr-border);
  border-radius: var(--radius-md);
  padding: var(--sp-3);
}

@media (max-width: 900px) {
  .pdf-toolbar {
    flex-wrap: wrap;
    height: auto;
    padding: var(--sp-2);
  }
  .pdf-study-sidebar {
    position: absolute;
    right: 0;
    top: 0;
    bottom: 0;
    z-index: 20;
    box-shadow: var(--shadow-xl);
  }
}