/* ─────────────────────────────────────────────────────────────────────────────
   FILE-BROWSER.CSS — Category Tabs, File List, and Search Input
   
   Accessibility Requirements:
   - All interactive elements: min-height 44px, min-width 44px
   - Visible focus ring with ≥3:1 contrast ratio (primary color #2563eb provides ~5.5:1)
   - 8px minimum spacing between adjacent touch targets
   ───────────────────────────────────────────────────────────────────────────── */

/* ─── Search Bar ────────────────────────────────────────────────────────────── */

#search-bar {
  margin-bottom: var(--space-lg);
}

#search-bar .search-label {
  display: block;
  margin-bottom: var(--space-sm);
  font-weight: var(--font-weight-semibold);
  font-size: var(--font-size-sm);
}

#search-input {
  width: 100%;
  padding: var(--space-md);
  font-size: var(--font-size-base);
  border: 2px solid var(--color-border);
  border-radius: var(--radius-md);
  background-color: var(--color-bg-alt);
  color: var(--color-text);
  transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
  min-height: 44px;
  min-width: 44px;
}

#search-input::placeholder {
  color: var(--color-text-muted);
}

#search-input:focus {
  outline: 3px solid var(--color-primary);
  outline-offset: 2px;
  border-color: var(--color-primary);
}

#search-input:active {
  border-color: var(--color-primary-dark);
}

.search-help {
  font-size: var(--font-size-xs);
  color: var(--color-text-muted);
  margin-top: var(--space-xs);
  margin-bottom: 0;
}

/* ─── Category Tabs Navigation ──────────────────────────────────────────────── */

#category-tabs {
  border-bottom: 2px solid var(--color-border);
  margin-bottom: var(--space-lg);
  display: flex;
  gap: var(--space-md);
  flex-wrap: wrap;
}

.category-tab {
  padding: var(--space-md) var(--space-lg);
  font-size: var(--font-size-base);
  font-weight: var(--font-weight-medium);
  color: var(--color-text-muted);
  border: 2px solid transparent;
  border-bottom: 3px solid transparent;
  cursor: pointer;
  transition: all var(--transition-fast);
  position: relative;
  min-height: 44px;
  min-width: 44px;
  display: flex;
  align-items: center;
  justify-content: center;
  background-color: transparent;
}

/* 8px spacing between adjacent targets (using gap on container and margin) */
.category-tab + .category-tab {
  margin-left: var(--space-xs);
}

.category-tab:hover {
  color: var(--color-primary);
  border-bottom-color: var(--color-primary-light);
}

.category-tab[aria-selected="true"] {
  color: var(--color-primary);
  border-bottom-color: var(--color-primary);
  font-weight: var(--font-weight-bold);
}

/* Visible focus ring with ≥3:1 contrast (primary blue #2563eb on white ~ 5.5:1) */
.category-tab:focus {
  outline: 3px solid var(--color-primary);
  outline-offset: -3px;
}

/* ─── File List Container ───────────────────────────────────────────────────── */

#file-list {
  min-height: 200px;
}

.file-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: var(--space-md);
}

/* File item: touch-target compliant with min dimensions and focus handling */
.file-item {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--space-md);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  background-color: var(--color-bg-alt);
  transition: all var(--transition-fast);
  min-height: 44px;
}

.file-item:hover {
  border-color: var(--color-primary);
  box-shadow: var(--shadow-md);
  background-color: rgba(37, 99, 235, 0.02);
}

/* Visible focus ring on file item (when button within is focused) */
.file-item:focus-within {
  outline: 3px solid var(--color-primary);
  outline-offset: 2px;
}

/* ─── File Info ─────────────────────────────────────────────────────────────── */

.file-info {
  flex: 1;
  min-width: 0;
  margin-right: var(--space-md);
}

.file-name {
  font-weight: var(--font-weight-semibold);
  color: var(--color-text);
  margin-bottom: var(--space-xs);
  word-break: break-word;
  overflow-wrap: break-word;
}

.file-meta {
  font-size: var(--font-size-sm);
  color: var(--color-text-muted);
  display: flex;
  gap: var(--space-xs);
  flex-wrap: wrap;
}

.file-type {
  background-color: var(--color-neutral-100);
  padding: 2px 6px;
  border-radius: var(--radius-sm);
  font-size: var(--font-size-xs);
  font-weight: var(--font-weight-medium);
  text-transform: uppercase;
}

.file-size {
  font-size: var(--font-size-sm);
}

/* ─── File Action Button ────────────────────────────────────────────────────── */

.file-action-btn {
  padding: var(--space-sm) var(--space-lg);
  min-height: 44px;
  min-width: 44px;
  background-color: var(--color-primary);
  color: white;
  border: 2px solid var(--color-primary);
  border-radius: var(--radius-md);
  font-weight: var(--font-weight-semibold);
  font-size: var(--font-size-sm);
  cursor: pointer;
  transition: all var(--transition-fast);
  white-space: nowrap;
  flex-shrink: 0;
  /* 8px spacing from file-info via margin */
  margin-left: var(--space-md);
}

.file-action-btn:hover {
  background-color: var(--color-primary-dark);
  border-color: var(--color-primary-dark);
  box-shadow: var(--shadow-md);
}

.file-action-btn:active {
  transform: scale(0.98);
}

/* Visible focus ring with ≥3:1 contrast */
.file-action-btn:focus {
  outline: 3px solid var(--color-primary);
  outline-offset: 2px;
}

/* ─── Empty State ───────────────────────────────────────────────────────────── */

.file-list-empty {
  padding: var(--space-2xl);
  text-align: center;
  color: var(--color-text-muted);
  font-size: var(--font-size-lg);
  background-color: var(--color-neutral-50);
  border: 2px dashed var(--color-border);
  border-radius: var(--radius-md);
  min-height: 200px;
  display: flex;
  align-items: center;
  justify-content: center;
}

/* ─── Mobile Adjustments ────────────────────────────────────────────────────– */

@media (max-width: 767px) {
  #category-tabs {
    flex-direction: column;
    gap: var(--space-md);
  }

  .category-tab {
    width: 100%;
    justify-content: flex-start;
  }

  /* 8px spacing between vertically stacked tabs on mobile */
  .category-tab + .category-tab {
    margin-left: 0;
    margin-top: var(--space-xs);
  }

  .file-item {
    flex-direction: column;
    align-items: flex-start;
  }

  .file-info {
    margin-right: 0;
    margin-bottom: var(--space-md);
    width: 100%;
  }

  .file-action-btn {
    width: 100%;
    margin-left: 0;
    margin-top: var(--space-md);
  }
}

/* ─── Tablet Adjustments ────────────────────────────────────────────────────── */

@media (min-width: 768px) and (max-width: 1199px) {
  .file-action-btn {
    padding: var(--space-md) var(--space-lg);
  }
}

/* ─── Desktop Adjustments ───────────────────────────────────────────────────── */

@media (min-width: 1200px) {
  #category-tabs {
    flex-direction: column;
    border-bottom: none;
    border-right: 2px solid var(--color-border);
    padding-right: var(--space-lg);
    margin-bottom: 0;
    margin-right: var(--space-lg);
    gap: var(--space-md);
  }

  .category-tab {
    width: 100%;
    justify-content: flex-start;
    border-bottom: 3px solid transparent;
    border-right: 3px solid transparent;
  }

  .category-tab:hover {
    border-bottom-color: transparent;
    border-right-color: var(--color-primary-light);
  }

  .category-tab[aria-selected="true"] {
    border-bottom-color: transparent;
    border-right-color: var(--color-primary);
  }

  /* 8px spacing between vertically stacked tabs */
  .category-tab + .category-tab {
    margin-left: 0;
    margin-top: var(--space-xs);
  }
}

/* ─── High Contrast Mode ────────────────────────────────────────────────────── */

@media (prefers-contrast: more) {
  .category-tab {
    border: 2px solid var(--color-neutral-400);
  }

  .category-tab[aria-selected="true"] {
    border: 2px solid var(--color-neutral-800);
    background-color: var(--color-neutral-100);
  }

  .file-item {
    border: 2px solid var(--color-neutral-600);
  }
}

/* ─── Reduced Motion ────────────────────────────────────────────────────────── */

@media (prefers-reduced-motion: reduce) {
  .category-tab,
  .file-item,
  .file-action-btn {
    transition: none;
  }
}