/* ===================================
   EXPANDABLE HEADER MOLECULE
   ===================================
   
   Shared clickable header pattern for expandable content.
   Used by: ExpandablePanel (panel-level), ExpandableList (item-level)
   
   ANTI-FRAGMENTATION:
   - Single molecule serves both Panel and List families
   - Variants adapt styling to match parent's visual family
   
   SPACING CONTRACT:
   - No external margins (parent controls spacing)
   - Internal padding defined here
*/

/* Base header container */
.expandable-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 var(--space-4);
  height: var(--space-12);
  background: var(--bg-surface);
  cursor: pointer;
  transition: background var(--duration-200) var(--easing-out);
  user-select: none;
}

.expandable-header:hover {
  background: var(--bg-panel);
}

/* Selected state (for list items) */
.expandable-header.selected {
  background: var(--color-primary-light);
}

/* Left side: checkbox, icon, title/content */
.expandable-header-left {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  flex: 1;
  min-width: 0;
  overflow: hidden;
}

/* Right side: badge, chevron */
.expandable-header-right {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  flex-shrink: 0;
}

/* Selection checkbox */
.expandable-header-checkbox {
  width: 18px;
  height: 18px;
  flex-shrink: 0;
  cursor: pointer;
  accent-color: var(--color-primary);
}

/* Leading icon container */
.expandable-header-icon {
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  color: var(--text-secondary);
}

/* Title text */
.expandable-header-title {
  font-size: var(--text-base);
  font-weight: 600;
  color: var(--text-primary);
  margin: 0;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

/* Custom content area */
.expandable-header-content {
  flex: 1;
  min-width: 0;
  overflow: hidden;
}

/* Chevron with rotation animation */
.expandable-header-chevron {
  display: flex;
  align-items: center;
  color: var(--text-muted);
  transition: transform var(--duration-200) var(--easing-out);
}

.expandable-header.expanded .expandable-header-chevron {
  transform: rotate(180deg);
}

/* Header actions container (between badge and chevron) */
.expandable-header-actions {
  display: flex;
  align-items: center;
  gap: var(--space-2);
}

/* Ensure actions don't inherit pointer cursor from header */
.expandable-header-actions .btn {
  cursor: pointer;
}

/* ===================================
   VARIANT: Panel Headers
   For ExpandablePanel - matches Panel (.dashboard-section) header styling
   =================================== */

.expandable-header.expandable-header-panel {
  height: auto;
  padding: 0;
  padding-bottom: var(--space-3);
  border-bottom: var(--border-width-1) solid var(--border-subtle);
  background: transparent;  /* Container handles background */
}

.expandable-header-panel .expandable-header-title {
  font-size: var(--text-base);  /* Matches Panel .section-title */
  font-weight: var(--font-weight-semibold);
}

/* Remove border when collapsed (no content visible) */
.expandable-panel.collapsed .expandable-header-panel {
  border-bottom-color: transparent;
  padding-bottom: 0;
}

/* ===================================
   VARIANT: List Item Headers (compact)
   For ExpandableList item-level headers
   =================================== */

.expandable-header.expandable-header-item {
  height: auto;
  min-height: var(--space-12);
  padding: var(--space-3) var(--space-4);
}

/* ===================================
   RESPONSIVE
   =================================== */

@media (max-width: 768px) {
  .expandable-header {
    padding: var(--space-3) var(--space-4);
    height: auto;
    min-height: var(--space-12);
  }

  .expandable-header-panel {
    padding-bottom: var(--space-2);
  }

  .expandable-header-title {
    font-size: var(--text-sm);
  }
}