Compact Navigation & Menu Panels

Canonical sizing and spacing rules for navigation sidebars, list panels, and compact menus across the project. Every value below is a hard default — deviate only with justification.

Sizing Tokens

Sidebar Container

Property	Value	Notes
Width	w-36 to w-44	Never wider than w-44 (~176px). Use w-36–w-40 when labels are short.
Background	bg-muted/30	Subtle tint, not solid bg-card.
Border	border-r border-border/60	60% opacity, not full border-border.
Visibility	hidden md:flex	Always hidden on mobile; use MobileDock or stacked list instead.
Scroll	Wrap content in <ScrollArea className="h-full w-full">	Never overflow-y-auto on the aside itself.

Nav Item — Top-Level (Flat or Parent)

Property	Value
Font	text-xs (12px)
Padding	px-3 py-1.5
Gap	gap-2
Icon	h-3.5 w-3.5
Active BG	bg-accent text-accent-foreground font-medium
Active icon	text-primary
Inactive	text-muted-foreground hover:text-foreground
Hover BG	hover:bg-muted/80
Shape	No rounded corners on rows — full-bleed highlight.

Nav Item — Child (Second Tier)

Property	Value
Font	text-[11px]
Padding	pl-8 pr-3 py-1
Gap	gap-1.5
Icon	h-3 w-3
Active	text-primary font-medium (no background)
Inactive icon	text-muted-foreground/60

Section Headers (Grouped Lists)

Property	Value
Font	text-[10px] font-medium uppercase tracking-wider — the ONE sanctioned 10px use (uppercase overline chrome; see ui-dense data-dense-rules "Absolute minimums")
Color	text-muted-foreground/70
Padding	px-3 pt-3 pb-1
Separator	border-t border-border/40 above the header, not <Separator> components.

Filter Bar / Chip Row

Property	Value
Container	px-3 py-1.5 flex items-center gap-1.5 flex-wrap
Chip (active)	px-2 py-0.5 rounded text-xs bg-primary text-primary-foreground
Chip (inactive)	px-2 py-0.5 rounded text-xs bg-muted/60 text-muted-foreground hover:bg-muted
Search input	h-7 text-xs pl-8 with icon at h-3.5 w-3.5
Select dropdown	h-6 px-1.5 rounded text-xs bg-muted/60 border-0

Footer / Status Bar

Property	Value
Padding	px-4 py-1.5 or px-4 py-2
Font	text-xs (status text is content — never below 12px)
Background	bg-muted/20
Border	border-t border-border/60
Buttons	h-7 text-xs gap-1 px-2.5

Anti-Patterns

These are the exact mistakes to fix when refactoring existing sidebars:

Bad	Fix
w-52, w-64, or wider	Reduce to w-36–w-44
text-sm on nav items	Use text-xs
py-2, py-3 on nav rows	Use py-1.5 (top-level) or py-1 (child)
gap-3 between icon and label	Use gap-2 (top-level) or gap-1.5 (child)
h-4 w-4 icons in nav	Use h-3.5 w-3.5 (top-level) or h-3 w-3 (child)
rounded-md on nav rows	Remove — use full-bleed row highlights
bg-primary text-primary-foreground active	Use bg-accent text-accent-foreground
p-3, p-4 wrapper padding inside sidebar	Use py-1 with no horizontal padding on the wrapper; let rows handle px-3
space-y-6 between groups	Use border-t border-border/40 separator + tight header
<Separator> component	Replace with a border-t on the section header
bg-card sidebar background	Use bg-muted/30
border-border (full opacity)	Use border-border/60
text-lg sidebar title	Remove header entirely or use text-xs uppercase section label

Two-Tier Expandable Pattern

For sidebars where a top-level item reveals sub-items (like Settings > Preferences):

const isExpanded = isActive && !!item.children;

{/* Parent */}
<Link href={item.children ? `${item.href}?tab=${item.children[0].param}` : item.href}
  className={cn(
    'flex items-center gap-2 px-3 py-1.5 transition-colors text-xs',
    'hover:bg-muted/80',
    isActive ? 'bg-accent text-accent-foreground font-medium'
             : 'text-muted-foreground hover:text-foreground',
  )}
>
  <span className={cn('shrink-0', isActive ? 'text-primary' : 'text-muted-foreground')}>
    {item.icon}
  </span>
  <span className="truncate">{item.title}</span>
</Link>

{/* Children — only when expanded */}
{isExpanded && (
  <div className="py-0.5">
    {item.children.map(child => (
      <Link key={child.param}
        href={`${item.href}?tab=${child.param}`}
        className={cn(
          'flex items-center gap-1.5 pl-8 pr-3 py-1 transition-colors text-[11px]',
          'hover:bg-muted/80',
          isChildActive ? 'text-primary font-medium'
                        : 'text-muted-foreground hover:text-foreground',
        )}
      >
        <span className={cn('shrink-0',
          isChildActive ? 'text-primary' : 'text-muted-foreground/60',
        )}>{child.icon}</span>
        <span className="truncate">{child.title}</span>
      </Link>
    ))}
  </div>
)}

Grouped Sections Pattern

For sidebars with categorized groups (like a file manager):

<aside className="hidden md:flex w-40 shrink-0 border-r border-border/60 bg-muted/30">
  <ScrollArea className="h-full w-full">
    <nav>
      {groups.map((group, i) => (
        <div key={group.label}>
          {/* Section header — acts as separator */}
          <div className={cn(
            'px-3 pt-3 pb-1 text-[10px] font-medium uppercase tracking-wider text-muted-foreground/70',
            i > 0 && 'border-t border-border/40',
          )}>
            {group.label}
          </div>
          {group.items.map(item => (
            <Link key={item.href} href={item.href}
              className={cn(
                'flex items-center gap-2 px-3 py-1.5 transition-colors text-xs',
                'hover:bg-muted/80',
                isActive ? 'bg-accent text-accent-foreground font-medium'
                         : 'text-muted-foreground hover:text-foreground',
              )}
            >
              <item.icon className={cn('h-3.5 w-3.5 shrink-0',
                isActive ? 'text-primary' : 'text-muted-foreground',
              )} />
              <span className="truncate">{item.label}</span>
            </Link>
          ))}
        </div>
      ))}
    </nav>
  </ScrollArea>
</aside>

Refactoring Checklist

When converting an existing sidebar to this system:

1. Container: w-36–w-44, bg-muted/30, border-r border-border/60
2. Remove wrapper padding: No p-3/p-4 on the scroll content wrapper
3. Items: text-xs, px-3 py-1.5, gap-2, icons h-3.5 w-3.5
4. Active state: bg-accent text-accent-foreground font-medium (not bg-primary)
5. No rounded rows: Remove rounded-md from item classes
6. Section separators: Replace <Separator> and space-y-6 with border-t border-border/40 on headers
7. Remove sidebar titles: Drop text-lg font-semibold headers; use section labels if grouping is needed
8. Icons: Lucide React only, h-3.5 w-3.5 for top-level, h-3 w-3 for children
9. ScrollArea: Wrap nav content in <ScrollArea>, not overflow-y-auto
10. Mobile: hidden md:flex on the aside; provide MobileDock or stacked list alternative