/**
 * HIG Accordion Component
 *
 * Shared accordion/collapse patterns used across the application.
 * Consolidates accordion patterns from 3+ files.
 *
 * Usage:
 *   <div class="hig-accordion">
 *     <div class="hig-accordion__item">
 *       <button class="hig-accordion__button">
 *         <span class="hig-accordion__title">Item Title</span>
 *         <span class="hig-accordion__icon">▼</span>
 *       </button>
 *       <div class="hig-accordion__panel">
 *         <div class="hig-accordion__content">Content</div>
 *       </div>
 *     </div>
 *   </div>
 *
 * Variants:
 *   .hig-accordion--bordered  - Bordered accordion items
 *   .hig-accordion--flush     - Flush accordion (no borders)
 */

/* ========================================
   Base Accordion
   ======================================== */

.hig-accordion {
  border: 1px solid var(--hig-color-border);
  border-radius: var(--hig-radius-small);
  overflow: hidden;
}

.hig-accordion__item {
  border-bottom: 1px solid var(--hig-color-border);
}

.hig-accordion__item:last-child {
  border-bottom: none;
}

/* ========================================
   Accordion Button (toggle)
   ======================================== */

.hig-accordion__button {
  width: 100%;
  padding: var(--hig-spacing-4) var(--hig-spacing-5);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--hig-spacing-3);
  background-color: var(--hig-color-surface);
  border: none;
  cursor: pointer;
  text-align: left;
  transition: background-color 0.16s ease;
  font-family: inherit;
}

.hig-accordion__button:hover {
  background-color: var(--hig-color-muted-surface);
}

.hig-accordion__button:focus {
  outline: none;
  background-color: var(--hig-color-muted-surface);
  box-shadow: inset 0 0 0 2px var(--hig-color-focus-ring);
}

.hig-accordion__button--expanded {
  background-color: var(--hig-color-muted-surface);
}

/* ========================================
   Accordion Title
   ======================================== */

.hig-accordion__title {
  flex: 1;
  font-size: var(--hig-font-size-base);
  font-weight: 650;
  color: var(--hig-color-text);
  line-height: 1.5;
}

/* ========================================
   Accordion Icon (chevron)
   ======================================== */

.hig-accordion__icon {
  flex-shrink: 0;
  font-size: 16px;
  color: var(--hig-color-text-secondary);
  transition: transform 0.2s ease;
}

.hig-accordion__button--expanded .hig-accordion__icon {
  transform: rotate(180deg);
}

/* ========================================
   Accordion Panel (content)
   ======================================== */

.hig-accordion__panel {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.3s ease;
}

.hig-accordion__panel--expanded {
  max-height: 2000px; /* Large enough for most content */
}

.hig-accordion__content {
  padding: var(--hig-spacing-4) var(--hig-spacing-5);
  color: var(--hig-color-text);
  font-size: var(--hig-font-size-base);
  line-height: 1.6;
}

.hig-accordion__content p {
  margin: 0 0 var(--hig-spacing-3) 0;
}

.hig-accordion__content p:last-child {
  margin-bottom: 0;
}

/* ========================================
   Bordered Variant
   ======================================== */

.hig-accordion--bordered .hig-accordion__item {
  border: 1px solid var(--hig-color-border);
  border-radius: var(--hig-radius-small);
  margin-bottom: var(--hig-spacing-3);
  overflow: hidden;
}

.hig-accordion--bordered .hig-accordion__item:last-child {
  margin-bottom: 0;
}

.hig-accordion--bordered {
  border: none;
  background: transparent;
}

/* ========================================
   Flush Variant (no borders)
   ======================================== */

.hig-accordion--flush {
  border: none;
  background: transparent;
}

.hig-accordion--flush .hig-accordion__button {
  padding-left: 0;
  padding-right: 0;
  background-color: transparent;
}

.hig-accordion--flush .hig-accordion__button:hover,
.hig-accordion--flush .hig-accordion__button:focus {
  background-color: transparent;
}

.hig-accordion--flush .hig-accordion__content {
  padding-left: 0;
  padding-right: 0;
}

/* ========================================
   Compact Variant
   ======================================== */

.hig-accordion--compact .hig-accordion__button {
  padding: var(--hig-spacing-3) var(--hig-spacing-4);
}

.hig-accordion--compact .hig-accordion__content {
  padding: var(--hig-spacing-3) var(--hig-spacing-4);
}

.hig-accordion--compact .hig-accordion__title {
  font-size: var(--hig-font-size-sm);
}

/* ========================================
   Accordion with Badge
   ======================================== */

.hig-accordion__badge {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 24px;
  height: 24px;
  padding: 0 var(--hig-spacing-2);
  background-color: var(--hig-color-primary);
  color: var(--text-on-accent);
  font-size: var(--hig-font-size-xs);
  font-weight: 500;
  border-radius: var(--hig-radius-small);
  margin-left: var(--hig-spacing-2);
}

/* ========================================
   Dark Theme Support
   ======================================== */

body.dark-theme .hig-accordion {
  border-color: var(--hig-color-border);
}

body.dark-theme .hig-accordion__item {
  border-bottom-color: var(--hig-color-border);
}

body.dark-theme .hig-accordion__button {
  background-color: var(--hig-color-surface);
}

body.dark-theme .hig-accordion__button:hover,
body.dark-theme .hig-accordion__button--expanded {
  background-color: var(--hig-color-muted-surface);
}

/* ========================================
   Responsive Design
   ======================================== */

@media (max-width: 768px) {
  .hig-accordion__button {
    padding: var(--hig-spacing-3) var(--hig-spacing-4);
  }

  .hig-accordion__content {
    padding: var(--hig-spacing-3) var(--hig-spacing-4);
  }

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