.sidebar-overlay {
  position: fixed;
  top: 0;
  left: 0;
  height: 100vh;
  width: 260px;
  background: var(--bg-surface);
  border-right: 1px solid var(--border);
  display: flex;
  flex-direction: column;
  padding: var(--sp-4) 0;
  overflow-y: auto;
  z-index: var(--z-modal);
  transform: translateX(-100%);
  transition: transform var(--t-slow) cubic-bezier(0.4, 0, 0.2, 1);
  box-shadow: var(--shadow-modal);
}
.sidebar-overlay.visible {
  transform: translateX(0);
}

.sidebar__brand {
  padding: var(--sp-3) var(--sp-5);
  font-size: var(--text-md);
  font-weight: 600;
  color: var(--accent);
  letter-spacing: var(--tracking-wide);
  margin-bottom: var(--sp-4);
}

.sidebar__nav {
  display: flex;
  flex-direction: column;
  gap: var(--sp-1);
  padding: 0 var(--sp-3);
}

.sidebar__link {
  display: flex;
  align-items: center;
  gap: var(--sp-3);
  padding: var(--sp-2) var(--sp-3);
  border-radius: var(--r-sm);
  font-size: var(--text-sm);
  color: var(--text-secondary);
  transition: background var(--t-fast), color var(--t-fast), transform var(--t-fast);
  text-decoration: none;
}
.sidebar__link:hover {
  background: var(--bg-elevated);
  color: var(--text-primary);
  transform: translateX(4px);
}
.sidebar__link.active {
  color: var(--accent);
  background: var(--accent-subtle);
}

.sidebar__icon {
  width: 18px;
  height: 18px;
  flex-shrink: 0;
  opacity: 0.7;
}
.sidebar__link:hover .sidebar__icon,
.sidebar__link.active .sidebar__icon {
  opacity: 1;
}

.sidebar__section {
  margin-top: var(--sp-3);
}
.sidebar__section-title {
  padding: var(--sp-2) var(--sp-3);
  font-size: var(--text-xs);
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: var(--tracking-wider);
  color: var(--text-muted);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: space-between;
  border-radius: var(--r-sm);
  transition: background var(--t-fast);
}
.sidebar__section-title:hover {
  background: var(--bg-elevated);
}
.sidebar__section-title::after {
  content: '▸';
  font-size: 10px;
  transition: transform var(--t-fast);
}
.sidebar__section.expanded .sidebar__section-title::after {
  transform: rotate(90deg);
}
.sidebar__section-links {
  display: none;
  flex-direction: column;
  gap: var(--sp-1);
  padding-left: var(--sp-5);
}
.sidebar__section.expanded .sidebar__section-links {
  display: flex;
}

.sidebar__toggle {
  position: fixed;
  top: var(--sp-3);
  left: var(--sp-3);
  z-index: var(--z-modal);
  background: var(--accent);
  color: var(--text-inverse);
  border: none;
  width: 40px;
  height: 40px;
  border-radius: var(--r-md);
  cursor: pointer;
  font-size: var(--text-md);
  display: flex;
  align-items: center;
  justify-content: center;
  transition: transform var(--t-fast), box-shadow var(--t-fast);
  box-shadow: var(--shadow-card);
}
.sidebar__toggle:hover {
  transform: scale(1.05);
  box-shadow: var(--shadow-modal);
}
.sidebar__toggle:active {
  transform: scale(0.95);
}
.sidebar__toggle.alert {
  background: var(--err);
  animation: sidebar-pulse 2s infinite;
}

@keyframes sidebar-pulse {
  0% { box-shadow: 0 0 0 0 var(--err-subtle); }
  50% { box-shadow: 0 0 0 8px transparent; }
  100% { box-shadow: 0 0 0 0 transparent; }
}

.sidebar__avatar {
  display: flex;
  justify-content: center;
  margin-bottom: var(--sp-5);
}
.sidebar__avatar-inner {
  width: 56px;
  height: 56px;
  border-radius: 50%;
  background: var(--accent);
  display: flex;
  align-items: center;
  justify-content: center;
  border: 2px solid var(--border);
  transition: transform var(--t-fast);
  cursor: pointer;
}
.sidebar__avatar-inner:hover {
  transform: scale(1.1);
}
.sidebar__avatar-inner svg {
  width: 32px;
  height: 32px;
}

.sidebar__notifications {
  padding: 0 var(--sp-3);
  margin-top: var(--sp-4);
  flex-shrink: 0;
}

.sidebar__notification {
  background: var(--bg-elevated);
  border-radius: var(--r-md);
  padding: var(--sp-3);
  margin: var(--sp-1) 0;
  border: 1px solid var(--border-subtle);
  transition: background var(--t-fast), transform var(--t-fast);
}
.sidebar__notification:hover {
  background: var(--bg-overlay);
  transform: translateY(-1px);
}
.sidebar__notification-icon {
  width: 32px;
  height: 32px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: bold;
  font-size: var(--text-xs);
  margin-bottom: var(--sp-2);
  color: var(--text-inverse);
}
.sidebar__notification-text {
  margin: 0 0 var(--sp-1) 0;
  font-size: var(--text-sm);
  line-height: var(--leading-tight);
  color: var(--text-primary);
}
.sidebar__notification-meta {
  font-size: var(--text-xs);
  color: var(--text-muted);
}

.sidebar-overlay::-webkit-scrollbar {
  width: 6px;
}
.sidebar-overlay::-webkit-scrollbar-track {
  background: var(--bg-elevated);
  border-radius: 3px;
}
.sidebar-overlay::-webkit-scrollbar-thumb {
  background: var(--border);
  border-radius: 3px;
}
.sidebar-overlay::-webkit-scrollbar-thumb:hover {
  background: var(--text-muted);
}