/* --- Hero Search --- */

.hero-search {
  max-width: 520px;
  margin: 1.25rem auto 0;
  position: relative;
}

.hero-search .kb-search-icon {
  position: absolute;
  left: 1rem;
  top: 50%;
  transform: translateY(-50%);
  color: var(--color-text-muted);
  display: flex;
  pointer-events: none;
}

.hero-search input {
  width: 100%;
  padding: 0.875rem 1rem 0.875rem 2.75rem;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  font: inherit;
  font-size: 1rem;
  color: var(--color-text);
  background: var(--color-surface-alt);
  box-shadow: var(--shadow-sm);
  transition: border-color 200ms ease, box-shadow 200ms ease, background 200ms ease;
}

.hero-search input:focus {
  outline: none;
  border-color: var(--color-primary);
  box-shadow: var(--focus-ring);
  background: var(--color-surface);
}

.hero-search input::placeholder {
  color: var(--color-text-muted);
  opacity: 0.7;
}

/* --- Category Section --- */

.kb-category {
  margin-bottom: 2.5rem;
}

.kb-category-header {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  margin-bottom: 1rem;
  padding-bottom: 0.75rem;
  border-bottom: 1px solid var(--color-border);
}

.kb-category-icon {
  width: 36px;
  height: 36px;
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--color-accent-blue-bg);
  color: var(--color-primary);
  flex-shrink: 0;
}

.kb-category-info {
  display: flex;
  align-items: baseline;
  gap: 0.75rem;
  flex: 1;
  min-width: 0;
}

.kb-category-info h2 {
  font-size: 1.0625rem;
  font-weight: 600;
  color: var(--color-text);
  margin: 0;
}

.kb-category-count {
  font-size: 0.75rem;
  color: var(--color-text-muted);
  font-weight: 500;
  white-space: nowrap;
}

/* --- Article Cards --- */

.kb-card-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.kb-card {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  padding: 0.875rem 1rem;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  text-decoration: none;
  color: var(--color-text);
  box-shadow: var(--shadow-sm);
  transition: border-color 200ms ease, box-shadow 200ms ease, transform 150ms ease;
  cursor: pointer;
}

.kb-card:hover {
  border-color: var(--color-primary);
  box-shadow: var(--shadow-card);
}

.kb-card:active {
  transform: scale(0.995);
}

.kb-card:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
}

.kb-card-icon {
  width: 32px;
  height: 32px;
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--color-surface-alt);
  color: var(--color-text-muted);
  flex-shrink: 0;
}

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

.kb-card-title {
  font-weight: 600;
  font-size: 0.9375rem;
  line-height: 1.4;
  display: block;
  color: var(--color-text);
  transition: color 200ms ease;
}

.kb-card:hover .kb-card-title {
  color: var(--color-primary);
}

.kb-date {
  display: block;
  color: var(--color-text-muted);
  font-size: 0.75rem;
  font-variant-numeric: tabular-nums;
  margin-top: 0.125rem;
}

.kb-card-arrow {
  color: var(--color-text-muted);
  font-size: 1.25rem;
  flex-shrink: 0;
  transition: transform 200ms ease, color 200ms ease;
}

.kb-card:hover .kb-card-arrow {
  color: var(--color-primary);
  transform: translateX(2px);
}

/* --- Article View --- */

.article-card {
  max-width: 100%;
}

.article-card article h1 {
  font-size: 1.75rem;
  font-weight: 700;
  margin-bottom: 0.5rem;
  letter-spacing: -0.025em;
  color: var(--color-text);
}

.kb-meta {
  color: var(--color-text-muted);
  font-size: 0.875rem;
  margin-bottom: 2rem;
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  align-items: center;
}

.kb-meta .category {
  background: var(--color-badge-open-bg);
  color: var(--color-badge-open-text);
  padding: 0.2rem 0.55rem;
  border-radius: 999px;
  font-size: 0.75rem;
  font-weight: 600;
}

.kb-body {
  line-height: 1.8;
  font-size: 1rem;
}

.kb-body h2 {
  font-size: 1.3rem;
  font-weight: 700;
  margin: 2rem 0 1rem;
  color: var(--color-text);
}

.kb-body h3 {
  font-size: 1.1rem;
  font-weight: 600;
  margin: 1.5rem 0 0.75rem;
  color: var(--color-text);
}

.kb-body h4 {
  font-size: 1rem;
  font-weight: 600;
  margin: 1.25rem 0 0.5rem;
  color: var(--color-text);
}

.kb-body code {
  background: var(--color-code-bg);
  padding: 0.15rem 0.4rem;
  border-radius: 4px;
  font-size: 0.9em;
}

.kb-body p {
  margin-bottom: 1rem;
}

.kb-body ul,
.kb-body ol {
  margin-bottom: 1rem;
  padding-left: 1.5rem;
}

.kb-body li {
  margin-bottom: 0.375rem;
}

/* --- Back Link --- */

.back-link {
  display: inline-flex;
  align-items: center;
  gap: 0.375rem;
  color: var(--color-primary);
  font-weight: 600;
  font-size: 0.875rem;
  text-decoration: none;
  cursor: pointer;
}

.back-link:hover {
  text-decoration: underline;
}

/* --- Empty & Error States --- */

.empty-state,
.error {
  padding: 3rem 2rem;
  text-align: center;
  color: var(--color-text-muted);
}

.empty-state svg {
  margin-bottom: 1rem;
  color: var(--color-text-muted);
  opacity: 0.5;
}

.empty-state p {
  font-size: 0.9375rem;
}

/* --- Responsive --- */

@media (max-width: 768px) {
  .hero-search {
    max-width: 100%;
  }
}

@media (max-width: 640px) {
  .kb-category-header {
    gap: 0.5rem;
  }

  .kb-category-icon {
    width: 32px;
    height: 32px;
  }

  .kb-card {
    padding: 0.75rem;
    gap: 0.5rem;
  }

  .kb-card-icon {
    display: none;
  }

  .article-card article h1 {
    font-size: 1.375rem;
  }
}