/**
 * Accordion - canonical Marbl UI Items §14 pattern.
 * Extracted from ui-items/preview.html inline styles on 
 * so both the library preview and any consumer (e.g. legal pages) pull
 * from a single source of truth.
 *
 * Usage:
 *   <div class="accordion">
 *     <div class="accordion__item">
 *       <button class="accordion__trigger" aria-expanded="false">
 *         <span>Question</span>
 *         <svg class="accordion__icon" viewBox="0 0 24 24" fill="none"
 *              stroke="currentColor" stroke-width="2" aria-hidden="true">
 *           <polyline points="6 9 12 15 18 9"/>
 *         </svg>
 *       </button>
 *       <div class="accordion__body">
 *         <div class="accordion__body-inner">
 *           <div class="accordion__content">Answer content.</div>
 *         </div>
 *       </div>
 *     </div>
 *     ...
 *   </div>
 *
 * JS: toggle `.is-open` on both the trigger AND its sibling .accordion__body.
 * One item open at a time (pattern: close all siblings, then open clicked).
 *
 * Depends on: core/marbl-v2.css tokens (--radius, --text-base, --text-sm,
 * --marbl-charcoal-light, --marbl-ember, --font-body).
 */

.accordion {
  display: flex;
  flex-direction: column;
  border-radius: var(--radius, 10px);
  overflow: hidden;
}

.accordion__item {
  background: var(--marbl-charcoal-light, #1d1a1b);
  border-bottom: 1px solid var(--marbl-white-06, rgba(255, 255, 255, 0.06));
}

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

.accordion__trigger {
  display: flex;
  align-items: center;
  justify-content: space-between;
  width: 100%;
  padding: var(--gap-sm) 0;
  background: transparent;
  border: none;
  color: var(--marbl-white-90, rgba(255, 255, 255, 0.9));
  font-family: var(--font-body, 'Inter', sans-serif);
  font-size: var(--text-base, 15px);
  font-weight: 500;
  cursor: pointer;
  text-align: left;
  transition: color 0.2s ease, padding 0.45s var(--ease-marbl, cubic-bezier(0.32, 0.72, 0, 1));
}

.accordion__trigger:hover { color: #fff; }
.accordion__trigger.is-open { color: var(--marbl-ember, #F35226); }

.accordion__trigger:focus-visible {
  outline: 2px solid var(--marbl-ember, #F35226);
  outline-offset: -2px;
}

.accordion__icon {
  width: 18px;
  height: 18px;
  flex-shrink: 0;
  opacity: 0.5;
  transition: transform 0.45s var(--ease-marbl, cubic-bezier(0.32, 0.72, 0, 1)), opacity 0.3s ease;
}

.accordion__trigger.is-open .accordion__icon {
  transform: rotate(180deg);
  opacity: 1;
}

/* Height animation via CSS grid — smooth, GPU-compositable, no max-height jank. */
.accordion__body {
  display: grid;
  grid-template-rows: 0fr;
  transition: grid-template-rows 0.45s var(--ease-marbl, cubic-bezier(0.32, 0.72, 0, 1));
}

.accordion__body.is-open { grid-template-rows: 1fr; }

.accordion__body-inner { overflow: hidden; }

.accordion__content {
  padding: 0 var(--gap-sm) var(--gap-sm);
  font-size: var(--text-sm, 13px);
  color: rgba(255, 255, 255, 0.45);
  line-height: 1.7;
}

/* Reduced motion — snap open/close, no transition. */
@media (prefers-reduced-motion: reduce) {
  .accordion__body,
  .accordion__icon {
    transition: none;
  }
}

/* ---------------------------------------------------------------------------
   LIGHT VARIANT (.accordion--light) - for warm paper/light bands.
   Added 15 Jun 2026 (Marbl Events) as part of the dark+light palette work;
   promote to the canonical ui-items/accordion.css when the light palette locks.
   Relies on the light tokens (--marbl-paper-border, --marbl-ink,
   --marbl-ink-muted, --ember-on-light) defined by the consuming site.
   --------------------------------------------------------------------------- */
.accordion--light .accordion__item {
  background: #fff;
  border-bottom: 1px solid var(--marbl-paper-border, #E8E5DF);
}
.accordion--light .accordion__trigger { color: var(--marbl-ink, #171415); }
.accordion--light .accordion__trigger:hover { color: var(--ember-on-light, #BB2F09); }
.accordion--light .accordion__trigger.is-open { color: var(--ember-on-light, #BB2F09); }
.accordion--light .accordion__content { color: var(--marbl-ink-muted, #5F5653); }

/* ---------------------------------------------------------------------------
   LINE VARIANT (.accordion--line) - halo-style. Hairline rows at rest;
   the OPEN item lifts into a white rounded card. "+" icon rotates 45deg to "x".
   Added 15 Jun 2026 (Marbl Events) - promote to canonical when light palette locks.
   Needs light tokens (--marbl-paper-border, --marbl-ink, --marbl-ink-muted).
   --------------------------------------------------------------------------- */
.accordion--line { overflow: visible; border-radius: 0; }
.accordion--line .accordion__item {
  background: transparent;
  border: 1px solid transparent;
  border-top-color: var(--marbl-paper-border, #E8E5DF);
  border-radius: 0; /* straight hairline rows at rest */
  transition: background 0.45s var(--ease-marbl, cubic-bezier(0.32,0.72,0,1)), box-shadow 0.45s var(--ease-marbl, cubic-bezier(0.32,0.72,0,1)), border-color 0.45s var(--ease-marbl, cubic-bezier(0.32,0.72,0,1)), margin 0.45s var(--ease-marbl, cubic-bezier(0.32,0.72,0,1));
}
/* Close the list with a bottom line so rows read as bordered top AND bottom. */
.accordion--line .accordion__item:last-child { border-bottom-color: var(--marbl-paper-border, #E8E5DF); }
/* Open row becomes a white card - matched to the site's content cards
   (same #fff, --radius-lg, paper border, soft shadow) for consistency. */
.accordion--line .accordion__item:has(.accordion__trigger.is-open) {
  background: var(--marbl-marble);
  border-color: transparent; /* no border on the open card */
  border-radius: var(--radius-lg, 20px);
  margin-block: var(--gap-sm, 20px); /* 20px breathing room above/below the open card */
}
/* No outer gap at the list edges - the first card needs no space above,
   the last needs none below (nothing to separate from). */
.accordion--line .accordion__item:first-child:has(.accordion__trigger.is-open) { margin-block-start: 0; }
.accordion--line .accordion__item:last-child:has(.accordion__trigger.is-open) { margin-block-end: 0; }
/* Only the two lines hugging an open card disappear; the rest stay. The line
   ABOVE is the open item's own top border (cleared by its no-border rule); this
   clears the line BELOW (the next row's top border). */
.accordion--line .accordion__item:has(.accordion__trigger.is-open) + .accordion__item {
  border-top-color: transparent;
}
.accordion--line .accordion__trigger { color: var(--marbl-ink, #171415); }
.accordion--line .accordion__trigger:hover { color: var(--marbl-ink, #171415); }
.accordion--line .accordion__trigger.is-open { color: var(--marbl-ink, #171415); }
.accordion--line .accordion__content { color: var(--marbl-ink-muted, #5F5653); }
/* Resting rows are flush (title left, icon right). When an item opens it lifts
   into a card — inset the trigger so the title + icon align with the padded
   content inside that card (animates via the trigger's padding transition). */
.accordion--line .accordion__item:has(.accordion__trigger.is-open) .accordion__trigger { padding-inline: var(--gap-sm); }
/* "+" icon, ember, full-opacity; rotate 45deg to "x" on open. */
/* Plain ember + (no box), slightly larger than the 18px base. Rotates 45deg to × on open. */
.accordion--line .accordion__icon { width: 24px; height: 24px; color: var(--marbl-ember, #F35226); opacity: 1; }
.accordion--line .accordion__trigger.is-open .accordion__icon { transform: rotate(45deg); }