/* ============================================================
   Knowledge Base — Wikipedia × Notion
   ============================================================ */

/* ── Dashboard ── */
.kb-dashboard {
  max-width: 1140px;
  margin: 0 auto;
  padding: 28px 40px 48px;
  animation: fadeInUp var(--duration-slow) var(--ease-out) both;
}

.kb-dashboard__header {
  display: flex;
  align-items: flex-start;
  gap: 16px;
  margin-bottom: 28px;
  flex-wrap: wrap;
}

.kb-dashboard__back {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  padding: 6px 10px 6px 6px;
  font-size: var(--font-size-sm);
  font-weight: var(--font-weight-medium);
  color: var(--color-text-secondary);
  border-radius: var(--radius-sm);
  flex-shrink: 0;
  margin-top: 4px;
  transition: background-color var(--duration-fast) var(--ease-out),
              color var(--duration-fast) var(--ease-out);
}

.kb-dashboard__back:hover {
  background-color: var(--color-bg-hover);
  color: var(--color-text-primary);
}

.kb-dashboard__heading { flex: 1; min-width: 0; }

.kb-dashboard__breadcrumb {
  font-size: var(--font-size-xs);
  font-weight: var(--font-weight-semibold);
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--color-accent);
  margin-bottom: 4px;
}

.kb-dashboard__title {
  font-size: var(--font-size-2xl);
  font-weight: var(--font-weight-bold);
  letter-spacing: var(--letter-spacing-tight);
  color: var(--color-text-primary);
  line-height: var(--line-height-tight);
  margin-bottom: 6px;
}

.kb-dashboard__subtitle {
  font-size: var(--font-size-sm);
  color: var(--color-text-secondary);
}

.kb-dashboard__add { flex-shrink: 0; margin-top: 4px; }

.kb-dashboard__count {
  font-size: var(--font-size-sm);
  color: var(--color-text-tertiary);
  margin-bottom: 20px;
}

/* Toolbar */
.kb-toolbar {
  display: flex;
  gap: 10px;
  margin-bottom: 8px;
  flex-wrap: wrap;
}

.kb-toolbar__search {
  display: flex;
  align-items: center;
  gap: 10px;
  flex: 1;
  min-width: 200px;
  height: 40px;
  padding: 0 14px;
  background-color: var(--color-bg-elevated);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  color: var(--color-text-tertiary);
  transition: border-color var(--duration-fast) var(--ease-out),
              box-shadow var(--duration-fast) var(--ease-out);
}

.kb-toolbar__search:focus-within {
  border-color: var(--color-accent);
  box-shadow: 0 0 0 3px var(--color-accent-soft);
}

.kb-toolbar__search-input {
  flex: 1;
  min-width: 0;
  font-size: var(--font-size-sm);
  font-family: inherit;
  color: var(--color-text-primary);
  border: none;
  outline: none;
  background: none;
}

.kb-toolbar__select {
  height: 40px;
  padding: 0 28px 0 12px;
  font-size: var(--font-size-sm);
  font-family: inherit;
  color: var(--color-text-secondary);
  background-color: var(--color-bg-elevated);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  cursor: pointer;
  appearance: none;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 24 24' fill='none' stroke='%239b9a97' stroke-width='2'%3E%3Cpolyline points='6 9 12 15 18 9'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 10px center;
}

/* Concept cards */
.kb-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: 16px;
}

.kb-card {
  display: flex;
  flex-direction: column;
  gap: 10px;
  padding: 22px;
  background-color: var(--color-bg-elevated);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-sm);
  cursor: pointer;
  text-align: left;
  font-family: inherit;
  color: inherit;
  transition:
    transform var(--duration-normal) var(--ease-out),
    box-shadow var(--duration-normal) var(--ease-out),
    border-color var(--duration-normal) var(--ease-out);
}

.kb-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-md);
  border-color: var(--color-border-strong);
}

.kb-card:active {
  transform: translateY(-1px) scale(0.99);
}

.kb-card__type {
  display: inline-block;
  padding: 3px 10px;
  font-size: 10px;
  font-weight: var(--font-weight-semibold);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--color-accent);
  background-color: var(--color-accent-soft);
  border-radius: var(--radius-full);
  width: fit-content;
}

.kb-card__title {
  font-size: var(--font-size-lg);
  font-weight: var(--font-weight-semibold);
  letter-spacing: var(--letter-spacing-tight);
  color: var(--color-text-primary);
  line-height: var(--line-height-tight);
}

.kb-card__overview {
  font-size: var(--font-size-sm);
  color: var(--color-text-secondary);
  line-height: var(--line-height-relaxed);
  display: -webkit-box;
  -webkit-line-clamp: 3;
  -webkit-box-orient: vertical;
  overflow: hidden;
  flex: 1;
}

.kb-card__meta {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  padding-top: 12px;
  border-top: 1px solid var(--color-border);
  margin-top: auto;
}

.kb-card__meta-item {
  font-size: 11px;
  font-weight: var(--font-weight-medium);
  color: var(--color-text-tertiary);
}

/* Empty state */
.kb-empty {
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
  padding: 56px 24px;
  background-color: var(--color-bg-elevated);
  border: 1px dashed var(--color-border-strong);
  border-radius: var(--radius-lg);
}

.kb-empty__icon {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 72px;
  height: 72px;
  margin-bottom: 16px;
  border-radius: var(--radius-lg);
  background-color: var(--color-bg-subtle);
  color: var(--color-text-tertiary);
}

.kb-empty__title {
  font-size: var(--font-size-lg);
  font-weight: var(--font-weight-semibold);
  color: var(--color-text-primary);
  margin-bottom: 6px;
}

.kb-empty__text {
  font-size: var(--font-size-sm);
  color: var(--color-text-secondary);
  max-width: 300px;
}

/* ── Form modal ── */
.kb-form-overlay {
  opacity: 0;
  transition: opacity var(--duration-normal) var(--ease-out);
}

.kb-form-overlay.is-visible { opacity: 1; }

.kb-form-modal {
  max-width: 640px;
  max-height: calc(100vh - 40px);
  overflow-y: auto;
  transform: translateY(12px) scale(0.98);
  opacity: 0;
  transition: transform var(--duration-normal) var(--ease-out),
              opacity var(--duration-normal) var(--ease-out);
}

.kb-form-overlay.is-visible .kb-form-modal {
  transform: translateY(0) scale(1);
  opacity: 1;
}

.kb-form__section {
  margin-bottom: 24px;
  padding-bottom: 20px;
  border-bottom: 1px solid var(--color-border);
}

.kb-form__section:last-of-type {
  border-bottom: none;
  margin-bottom: 0;
  padding-bottom: 0;
}

.kb-form__section-title {
  font-size: var(--font-size-xs);
  font-weight: var(--font-weight-semibold);
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--color-text-tertiary);
  margin-bottom: 14px;
}

/* ============================================================
   Article Detail Page — Wikipedia layout + Notion blocks
   ============================================================ */
.kb-article {
  animation: fadeInUp var(--duration-slow) var(--ease-out) both;
}

.kb-article__toolbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding: 12px 32px;
  background-color: var(--color-bg-elevated);
  border-bottom: 1px solid var(--color-border);
  position: sticky;
  top: 0;
  z-index: 10;
}

.kb-article__back {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  padding: 6px 10px 6px 6px;
  font-size: var(--font-size-sm);
  font-weight: var(--font-weight-medium);
  color: var(--color-text-secondary);
  border-radius: var(--radius-sm);
  transition: background-color var(--duration-fast) var(--ease-out),
              color var(--duration-fast) var(--ease-out);
}

.kb-article__back:hover {
  background-color: var(--color-bg-hover);
  color: var(--color-text-primary);
}

.kb-article__actions {
  display: flex;
  gap: 8px;
}

.kb-article__layout {
  display: grid;
  grid-template-columns: 1fr 280px;
  gap: 40px;
  max-width: 1100px;
  margin: 0 auto;
  padding: 40px 32px 64px;
  align-items: start;
}

.kb-article__main {
  min-width: 0;
}

.kb-article__breadcrumb {
  font-size: var(--font-size-xs);
  color: var(--color-text-tertiary);
  margin-bottom: 8px;
}

.kb-article__title {
  font-family: Georgia, 'Times New Roman', Times, serif;
  font-size: 2.25rem;
  font-weight: 400;
  letter-spacing: -0.01em;
  color: var(--color-text-primary);
  line-height: 1.15;
  margin-bottom: 16px;
  border-bottom: 1px solid var(--color-border);
  padding-bottom: 16px;
}

.kb-article__overview {
  font-size: 1.0625rem;
  font-style: italic;
  color: var(--color-text-secondary);
  line-height: var(--line-height-relaxed);
  margin-bottom: 24px;
}

.kb-article__divider {
  height: 1px;
  background: linear-gradient(to right, var(--color-border), transparent);
  margin-bottom: 28px;
}

.kb-article__section {
  margin-bottom: 32px;
}

.kb-article__heading {
  font-family: Georgia, 'Times New Roman', Times, serif;
  font-size: 1.375rem;
  font-weight: 400;
  color: var(--color-text-primary);
  padding-bottom: 6px;
  margin-bottom: 14px;
  border-bottom: 1px solid var(--color-border);
}

.kb-article__prose {
  font-size: var(--font-size-base);
  color: var(--color-text-primary);
  line-height: 1.8;
}

.kb-article__prose.md-preview,
.kb-callout__body.md-preview {
  max-width: none;
  padding: 0;
  font-size: var(--font-size-base);
}

.kb-callout__body.md-preview .md-heading {
  margin-top: 0.75em;
}

/* Timeline */
.kb-timeline {
  list-style: none;
  border-left: 2px solid var(--color-accent-soft);
  margin-left: 8px;
  padding-left: 0;
}

.kb-timeline__item {
  position: relative;
  padding: 0 0 20px 24px;
}

.kb-timeline__item::before {
  content: '';
  position: absolute;
  left: -7px;
  top: 6px;
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background-color: var(--color-accent);
  border: 2px solid var(--color-bg);
  box-shadow: 0 0 0 2px var(--color-accent-soft);
}

.kb-timeline__item:last-child { padding-bottom: 0; }

.kb-timeline__period {
  display: block;
  font-size: var(--font-size-sm);
  font-weight: var(--font-weight-semibold);
  color: var(--color-accent);
  margin-bottom: 2px;
}

.kb-timeline__event {
  font-size: var(--font-size-base);
  color: var(--color-text-secondary);
  line-height: var(--line-height-relaxed);
}

/* Lists */
.kb-list {
  padding-left: 1.25rem;
  color: var(--color-text-primary);
  line-height: 1.75;
}

.kb-list li { margin-bottom: 8px; }
.kb-list--facts li::marker { color: var(--color-accent); }
.kb-list--refs { font-size: var(--font-size-sm); color: var(--color-text-secondary); }

/* Tags */
.kb-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.kb-tag {
  display: inline-block;
  padding: 5px 12px;
  font-size: var(--font-size-xs);
  font-weight: var(--font-weight-medium);
  color: var(--color-text-secondary);
  background-color: var(--color-bg-subtle);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-full);
  transition: background-color var(--duration-fast) var(--ease-out);
}

.kb-tag--chapter {
  color: var(--color-accent);
  background-color: var(--color-accent-muted);
  border-color: transparent;
}

.kb-tag--sm {
  padding: 3px 8px;
  font-size: 11px;
}

/* PYQs */
.kb-pyqs {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.kb-pyq {
  padding: 14px 16px;
  font-size: var(--font-size-sm);
  color: var(--color-text-primary);
  line-height: var(--line-height-relaxed);
  background-color: var(--color-bg-subtle);
  border-left: 3px solid var(--color-accent);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
}

/* Notion-style callout */
.kb-callout {
  padding: 16px 18px;
  border-radius: var(--radius-md);
  border: 1px solid var(--color-border);
}

.kb-callout--revision {
  background-color: var(--color-accent-muted);
  border-color: color-mix(in srgb, var(--color-accent) 25%, var(--color-border));
}

.kb-callout__label {
  font-size: var(--font-size-xs);
  font-weight: var(--font-weight-semibold);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--color-accent);
  margin-bottom: 8px;
}

.kb-callout__body {
  font-size: var(--font-size-sm);
  color: var(--color-text-primary);
  line-height: var(--line-height-relaxed);
}

/* Wikipedia-style infobox */
.kb-infobox {
  position: sticky;
  top: calc(var(--navbar-height) + 16px);
  padding: 18px;
  background-color: var(--color-bg-elevated);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-sm);
  font-size: var(--font-size-sm);
}

.kb-infobox__title {
  font-family: Georgia, 'Times New Roman', Times, serif;
  font-size: var(--font-size-base);
  font-weight: 400;
  text-align: center;
  padding-bottom: 12px;
  margin-bottom: 12px;
  border-bottom: 1px solid var(--color-border);
  color: var(--color-text-primary);
}

.kb-infobox__list { margin: 0; }

.kb-infobox__row {
  display: grid;
  grid-template-columns: 90px 1fr;
  gap: 8px;
  padding: 6px 0;
  border-bottom: 1px solid var(--color-border);
}

.kb-infobox__row:last-child { border-bottom: none; }

.kb-infobox__row dt {
  font-weight: var(--font-weight-semibold);
  color: var(--color-text-tertiary);
  font-size: 11px;
  text-transform: uppercase;
  letter-spacing: 0.03em;
}

.kb-infobox__row dd {
  color: var(--color-text-primary);
  margin: 0;
}

.kb-infobox__section {
  margin-top: 14px;
  padding-top: 14px;
  border-top: 1px solid var(--color-border);
}

.kb-infobox__section-title {
  font-size: 11px;
  font-weight: var(--font-weight-semibold);
  text-transform: uppercase;
  letter-spacing: 0.04em;
  color: var(--color-text-tertiary);
  margin-bottom: 8px;
}

.kb-infobox__tags {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
}

/* ── Responsive ── */
@media (max-width: 900px) {
  .kb-article__layout {
    grid-template-columns: 1fr;
    padding: 28px 20px 48px;
  }

  .kb-infobox {
    position: static;
    order: -1;
  }
}

@media (max-width: 768px) {
  .kb-dashboard {
    padding: 20px 16px 40px;
  }

  .kb-dashboard__header {
    flex-direction: column;
    align-items: stretch;
  }

  .kb-dashboard__add { width: 100%; margin-top: 0; }

  .kb-toolbar { flex-direction: column; }

  .kb-toolbar__select { width: 100%; }

  .kb-grid { grid-template-columns: 1fr; }

  .kb-article__toolbar {
    padding: 10px 16px;
    flex-wrap: wrap;
  }

  .kb-article__title { font-size: 1.75rem; }

  .kb-article__actions {
    width: 100%;
    justify-content: flex-end;
  }
}

@media (max-width: 480px) {
  .kb-article__actions .btn {
    flex: 1;
    justify-content: center;
  }
}