.sidebar {
  grid-area: sidebar;
  background: var(--sidebar-bg);
  display: flex;
  flex-direction: column;
  overflow: hidden;
  transition: width var(--transition);
  position: sticky;
  top: 0;
  height: 100vh;
  z-index: 100;
}

/* ── Logo / Brand ─────────────────────────────────────── */
.sidebar-brand {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  padding: var(--space-md) var(--space-md);
  height: var(--header-height);
  border-bottom: 1px solid rgba(255,255,255,.07);
  text-decoration: none;
  overflow: hidden;
  flex-shrink: 0;
}

.sidebar-brand__logo {
  width: 32px;
  height: 32px;
  background: var(--color-primary);
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  color: #fff;
  font-size: 18px;
  font-weight: 700;
  flex-shrink: 0;
}

.sidebar-brand__name {
  font-size: var(--font-base);
  font-weight: 700;
  color: #fff;
  white-space: nowrap;
  line-height: 1.2;
}

.sidebar-brand__sub {
  font-size: 10px;
  color: var(--sidebar-icon);
  font-weight: 400;
}

/* ── Navigation ───────────────────────────────────────── */
.sidebar-nav {
  flex: 1;
  overflow-y: auto;
  overflow-x: hidden;
  padding: var(--space-sm) 0;
  scrollbar-width: thin;
  scrollbar-color: rgba(255,255,255,.1) transparent;
}

.sidebar-nav::-webkit-scrollbar { width: 4px; }
.sidebar-nav::-webkit-scrollbar-thumb { background: rgba(255,255,255,.1); border-radius: 2px; }

.nav-section {
  margin-bottom: var(--space-xs);
}

.nav-section__label {
  font-size: 10px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 1px;
  color: var(--sidebar-icon);
  padding: var(--space-md) var(--space-md) var(--space-xs);
  white-space: nowrap;
  overflow: hidden;
}

.nav-item {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  padding: 10px var(--space-md);
  color: var(--sidebar-text);
  text-decoration: none;
  border-radius: 0;
  cursor: pointer;
  transition: background var(--transition), color var(--transition);
  white-space: nowrap;
  overflow: hidden;
  margin: 2px 8px;
  border-radius: var(--radius-md);
}

.nav-item:hover {
  background: var(--sidebar-hover-bg);
  color: #fff;
}

.nav-item.active {
  background: var(--sidebar-active-bg);
  color: var(--sidebar-active-text);
}

.nav-item.active .nav-item__icon { color: var(--color-primary); }

.nav-item__icon {
  font-size: 18px;
  color: var(--sidebar-icon);
  flex-shrink: 0;
  width: 20px;
  text-align: center;
  transition: color var(--transition);
}

.nav-item:hover .nav-item__icon { color: #fff; }

.nav-item__label {
  font-size: var(--font-base);
  font-weight: 500;
  flex: 1;
}

.nav-item__badge {
  background: var(--color-primary);
  color: #fff;
  font-size: 10px;
  font-weight: 600;
  padding: 1px 6px;
  border-radius: var(--radius-full);
  flex-shrink: 0;
}

/* ── Collapse toggle ──────────────────────────────────── */
.sidebar-footer {
  padding: var(--space-sm) var(--space-md);
  border-top: 1px solid rgba(255,255,255,.07);
  flex-shrink: 0;
}

.sidebar-collapse-btn {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  padding: 10px var(--space-sm);
  color: var(--sidebar-text);
  cursor: pointer;
  border: none;
  background: none;
  border-radius: var(--radius-md);
  width: 100%;
  transition: background var(--transition);
  overflow: hidden;
}

.sidebar-collapse-btn:hover {
  background: var(--sidebar-hover-bg);
  color: #fff;
}

.sidebar-collapse-btn .nav-item__icon { color: var(--sidebar-icon); }
.sidebar-collapse-btn:hover .nav-item__icon { color: #fff; }

/* ── Collapsed state ──────────────────────────────────── */
.app-shell.sidebar-collapsed .sidebar-brand__name,
.app-shell.sidebar-collapsed .sidebar-brand__sub,
.app-shell.sidebar-collapsed .nav-section__label,
.app-shell.sidebar-collapsed .nav-item__label,
.app-shell.sidebar-collapsed .nav-item__badge,
.app-shell.sidebar-collapsed .sidebar-collapse-btn .nav-item__label {
  display: none;
}

.app-shell.sidebar-collapsed .nav-item,
.app-shell.sidebar-collapsed .sidebar-collapse-btn {
  justify-content: center;
  padding: 10px;
}

/* Tooltip on collapsed state */
.app-shell.sidebar-collapsed .nav-item { position: relative; }
.app-shell.sidebar-collapsed .nav-item::after {
  content: attr(data-label);
  position: absolute;
  left: calc(var(--sidebar-collapsed) - 4px);
  top: 50%;
  transform: translateY(-50%);
  background: var(--color-text-primary);
  color: #fff;
  padding: 4px 10px;
  border-radius: var(--radius-sm);
  font-size: var(--font-sm);
  white-space: nowrap;
  opacity: 0;
  pointer-events: none;
  transition: opacity var(--transition);
  z-index: 200;
}
.app-shell.sidebar-collapsed .nav-item:hover::after { opacity: 1; }