/* ============================================================================
   SHARE BUTTON COMPONENT

   "Share" button + popover menu with platform options + copy-link.
   Used by FeatureLayout, LearnLayout, LegalLayout to surface OG-image
   social share. Server-rendered HTML; share-button.js only toggles
   open/closed state and handles copy-link.

   Required HTML structure:
     <div class="share-button-group" data-share-url="...">
       <button class="share-button-trigger" aria-haspopup="menu" aria-expanded="false">
         <span class="share-button-trigger__icon">{svg}</span>
         <span class="share-button-trigger__label">Share</span>
       </button>
       <button class="share-menu-backdrop" tabindex="-1"></button>
       <div class="share-menu" role="menu" aria-hidden="true">
         <div class="share-menu-header">...</div>
         <div class="share-menu-grid">
           <a class="share-menu-item">...</a>
           ...
         </div>
         <div class="share-menu-divider"></div>
         <button class="share-menu-copy">...</button>
       </div>
     </div>

   Modifier classes added by share-button.js:
   - .share-button-group--open  applied to wrapper when menu is open
   ============================================================================ */

.share-button-group {
  position: relative;
  top: -10px;
  display: inline-flex;
}

/* ===== Trigger button ===== */

.share-button-trigger {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.5rem 0.9rem;
  background: transparent;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  color: var(--text-secondary);
  font-family: inherit;
  font-size: 0.875rem;
  font-weight: 500;
  cursor: pointer;
  transition: border-color var(--transition-fast), color var(--transition-fast), background var(--transition-fast);
}

.share-button-trigger:hover,
.share-button-group--open .share-button-trigger {
  border-color: var(--sky-blue);
  color: var(--text-primary);
  background: rgba(96, 165, 250, 0.08);
}

.share-button-trigger:focus {
  outline: none;
}

.share-button-trigger:focus-visible {
  outline: 2px solid var(--sky-blue);
  outline-offset: 2px;
}

.share-button-trigger__icon {
  display: inline-flex;
  align-items: center;
}

/* ===== Backdrop ===== */

.share-menu-backdrop {
  position: fixed;
  inset: 0;
  z-index: 999;
  border: 0;
  padding: 0;
  background: rgba(0, 0, 0, 0);
  cursor: default;
  display: none;
  transition: background 0.2s ease;
}

.share-button-group--open .share-menu-backdrop {
  display: block;
  background: rgba(0, 0, 0, 0.35);
}

/* ===== Menu ===== */

/* Anchor the menu's right edge to the trigger's right edge so it
   always extends LEFTWARD from the trigger. Triggers tend to live
   on the right side of toolbars; centering on the trigger pushed
   the menu off the right edge of the viewport on narrower screens. */
.share-menu {
  position: absolute;
  top: calc(100% + 8px);
  right: 0;
  width: min(320px, calc(100vw - 24px));
  z-index: 1000;
  background: var(--bg-card, var(--section-dark));
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md, 8px);
  box-shadow: 0 12px 32px rgba(0, 0, 0, 0.4);
  opacity: 0;
  transform: translateY(8px) scale(0.96);
  transform-origin: top right;
  pointer-events: none;
  transition: opacity 0.18s ease, transform 0.18s ease;
}

.share-button-group--open .share-menu {
  opacity: 1;
  transform: translateY(0) scale(1);
  pointer-events: auto;
}

.share-menu-header {
  padding: 1rem 1.25rem 0.75rem;
  font-size: 0.75rem;
  font-weight: 700;
  color: var(--text-secondary);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.share-menu-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 2px;
  padding: 0 0.5rem;
}

.share-menu-item {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.5rem 0.75rem;
  border-radius: 4px;
  color: var(--text-primary);
  text-decoration: none;
  font-size: 0.95rem;
  transition: background var(--transition-fast);
}

.share-menu-item:hover {
  background: rgba(96, 165, 250, 0.1);
  color: var(--text-primary);
  text-decoration: none;
}

.share-menu-item__icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 28px;
  height: 28px;
  flex-shrink: 0;
}

.share-menu-item__label {
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.share-menu-divider {
  height: 1px;
  background: var(--border-color);
  margin: 0.5rem 1.25rem;
}

.share-menu-copy {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  width: 100%;
  padding: 0.5rem 1.25rem 1rem;
  border: none;
  background: transparent;
  color: var(--text-primary);
  font-family: inherit;
  font-size: 0.95rem;
  text-align: left;
  cursor: pointer;
  border-radius: 0 0 var(--radius-md, 8px) var(--radius-md, 8px);
  transition: background var(--transition-fast);
}

.share-menu-copy:hover {
  background: rgba(96, 165, 250, 0.1);
}

.share-menu-copy:focus,
.share-menu-item:focus {
  outline: none;
}

.share-menu-copy:focus-visible,
.share-menu-item:focus-visible {
  outline: 2px solid var(--sky-blue);
  outline-offset: -2px;
}