/* ============================================================
   Sidebar — persistent left navigation, Dark Glass system.
   Desktop: fixed collapsible rail under the sticky top nav.
   Mobile/tablet (<1024px): off-canvas drawer + backdrop.
   ============================================================ */

.sidebar {
  position: fixed;
  top: var(--nav-height);
  left: 0;
  width: var(--sidebar-width);
  height: calc(100vh - var(--nav-height));
  background: var(--bg-2);
  border-right: 1px solid var(--border);
  z-index: var(--sidebar-z);
  overflow-y: auto;
  overflow-x: hidden;
  display: flex;
  flex-direction: column;
  transition: width var(--t-med) var(--ease-out);
}

.sidebar[data-collapsed="true"] {
  width: var(--sidebar-width-collapsed);
}

.sidebar[data-collapsed="true"] .sidebar-link-label {
  display: none;
}

.sidebar-collapse-toggle {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 2rem;
  height: 2rem;
  margin: 0.75rem 0.75rem 0.25rem auto;
  background: transparent;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  color: var(--text-muted);
  cursor: pointer;
  transition: background var(--t-fast), color var(--t-fast);
}

.sidebar-collapse-toggle:hover {
  background: var(--surface-hover);
  color: var(--text);
}

.sidebar-collapse-toggle svg {
  width: 1rem;
  height: 1rem;
  transition: transform var(--t-med) var(--ease-out);
}

.sidebar[data-collapsed="true"] .sidebar-collapse-toggle svg {
  transform: rotate(180deg);
}

.sidebar-nav {
  display: flex;
  flex-direction: column;
  gap: 0.15rem;
  padding: 0.25rem 0.75rem 1rem;
}

.sidebar-link {
  display: flex;
  align-items: center;
  gap: 0.65rem;
  padding: 0.55rem 0.65rem;
  border-radius: var(--radius-sm);
  color: var(--text-muted);
  font-family: var(--font-sans);
  font-size: 0.875rem;
  text-decoration: none;
  white-space: nowrap;
  transition: background var(--t-fast), color var(--t-fast);
}

.sidebar-icon {
  flex: none;
  width: 1.15rem;
  height: 1.15rem;
}

/* Collapsed rail: hide labels (rule below) and center the icons. */
.sidebar[data-collapsed="true"] .sidebar-link {
  justify-content: center;
  padding-left: 0;
  padding-right: 0;
  gap: 0;
}

.sidebar[data-collapsed="true"] .sidebar-divider {
  margin-left: 0.75rem;
  margin-right: 0.75rem;
}

.sidebar[data-collapsed="true"] .sidebar-collapse-toggle {
  margin-right: auto;
}

.sidebar-link:hover {
  background: var(--surface);
  color: var(--text);
}

.sidebar-link.active {
  background: var(--surface-active);
  color: var(--accent-soft);
}

.sidebar-divider {
  height: 1px;
  margin: 0.5rem 0.65rem;
  background: var(--border-light);
}

/* ── Contextual sub-nav (Phase 2: wizard steps, dataset list) ───────────────── */
.sidebar-subnav {
  display: flex;
  flex-direction: column;
  gap: 0.1rem;
  padding: 0 0.75rem 1rem;
}

.sidebar[data-collapsed="true"] .sidebar-subnav {
  display: none;
}

.sidebar-substep {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  padding: 0.35rem 0.15rem;
  font-family: var(--font-sans);
  font-size: 0.8rem;
  color: var(--text-muted);
}

.sidebar-substep.active {
  color: var(--text);
  font-weight: 600;
}

.sidebar-substep-marker {
  flex: none;
  display: flex;
  align-items: center;
  justify-content: center;
  width: 1.35rem;
  height: 1.35rem;
  border-radius: 50%;
  font-size: 0.65rem;
  font-weight: 700;
  background: var(--border);
  color: var(--text-muted);
}

.sidebar-substep.active .sidebar-substep-marker {
  background: var(--text);
  color: var(--bg);
}

.sidebar-substep.done .sidebar-substep-marker {
  background: var(--accent);
  color: #fff;
}

.sidebar-substep-label {
  color: inherit;
  text-decoration: none;
  white-space: nowrap;
}

a.sidebar-substep-link {
  display: block;
  color: var(--text-muted);
  text-decoration: none;
  padding: 0.35rem 0.15rem;
  font-size: 0.8rem;
  border-radius: var(--radius-sm);
  overflow: hidden;
  text-overflow: ellipsis;
}

a.sidebar-substep-link:hover {
  background: var(--surface);
  color: var(--text);
}

a.sidebar-substep-link.active {
  color: var(--accent-soft);
  font-weight: 600;
}

a.sidebar-substep-label:hover {
  color: var(--accent-soft);
}

.sidebar-backdrop {
  display: none;
}

/* ── Content offset ────────────────────────────────────────────────────────── */
.app-shell {
  margin-left: var(--sidebar-width);
  transition: margin-left var(--t-med) var(--ease-out);
}

body[data-sidebar-collapsed="true"] .app-shell {
  margin-left: var(--sidebar-width-collapsed);
}

/* ── Mobile / tablet: off-canvas drawer ──────────────────────────────────────
   Distinct breakpoint from the existing 768px padding breakpoint in this file
   — that one only tightens spacing, this one changes the nav paradigm. */
@media (max-width: 1023px) {
  .sidebar {
    transform: translateX(-100%);
    width: min(var(--sidebar-width), 80vw);
  }

  body[data-sidebar-open="true"] .sidebar {
    transform: translateX(0);
  }

  .app-shell,
  body[data-sidebar-collapsed="true"] .app-shell {
    margin-left: 0;
  }

  .sidebar-collapse-toggle {
    display: none;
  }

  .sidebar-hamburger {
    display: inline-flex;
  }

  .sidebar-backdrop {
    position: fixed;
    inset: var(--nav-height) 0 0 0;
    background: rgba(0, 0, 0, 0.5);
    z-index: calc(var(--sidebar-z) - 1);
  }

  body[data-sidebar-open="true"] .sidebar-backdrop {
    display: block;
  }
}

@media (min-width: 1024px) {
  .sidebar-hamburger {
    display: none;
  }
}