/* ============================================================================
 * sidebar-toggle.css
 * Collapse/expand toggle for sidebar on practice and study pages.
 * Works with both .app-shell (practice) and .layout (study) grid parents.
 * ============================================================================ */

/* --- Toggle Button (expanded state) --- */
.sidebar-toggle-btn {
  position: absolute;
  top: 50%;
  right: -18px;
  transform: translateY(-50%);
  z-index: 100;
  width: 36px;
  height: 36px;
  border-radius: 50%;
  border: 1px solid var(--border-soft, rgba(148, 163, 184, 0.2));
  background: var(--surface-muted, rgba(148, 163, 184, 0.08));
  color: var(--text-muted, #94a3b8);
  font-size: 14px;
  line-height: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: background 0.2s ease, color 0.2s ease;
  padding: 0;
  font-family: inherit;
}

.sidebar-toggle-btn:hover {
  background: var(--primary-soft, rgba(255, 138, 91, 0.15));
  color: var(--text-main, #f1f5f9);
}

.sidebar-toggle-btn:focus-visible {
  outline: 2px solid var(--focus-ring);
  outline-offset: 2px;
}

/* --- Transitions (only after initial load to avoid flash) --- */
.sidebar-toggle-ready .app-shell {
  transition: grid-template-columns 0.3s ease;
}

.sidebar-toggle-ready .layout {
  transition: grid-template-columns 0.3s ease;
}

.sidebar-toggle-ready .sidebar {
  transition: width 0.3s ease, min-width 0.3s ease, opacity 0.3s ease,
              padding 0.3s ease, border-color 0.3s ease;
}

/* --- Collapsed State (practice pages — .app-shell parent) --- */
.sidebar-collapsed .app-shell {
  grid-template-columns: 0px minmax(0, 1fr);
}

.sidebar-collapsed .app-shell > .sidebar {
  width: 0;
  min-width: 0;
  overflow: hidden;
  padding: 0;
  border-color: transparent;
  opacity: 0;
  pointer-events: none;
}

/* --- Collapsed State (study pages — .layout parent) --- */
.sidebar-collapsed .layout {
  grid-template-columns: 0px 1fr;
}

.sidebar-collapsed .layout > .sidebar {
  width: 0;
  min-width: 0;
  overflow: hidden;
  padding: 0;
  border-color: transparent;
  opacity: 0;
  pointer-events: none;
}

/* --- Toggle button when collapsed: reposition to viewport edge --- */
.sidebar-collapsed .sidebar-toggle-btn {
  position: fixed;
  top: 50%;
  left: 8px;
  right: auto;
  transform: translateY(-50%);
  z-index: 100;
  pointer-events: auto;
  opacity: 1;
}

/* --- Hide toggle on mobile (sidebar already collapsed via single-column layout) --- */
@media (max-width: 960px) {
  .sidebar-toggle-btn {
    display: none !important;
  }
}