Token	Usage	Class Examples
`background` / `foreground`	Page background, main text	`bg-background`, `text-foreground`
`card` / `card-foreground`	Card surfaces	`bg-card`, `text-card-foreground`
`popover` / `popover-foreground`	Dropdowns, tooltips	`bg-popover`, `text-popover-foreground`
`primary` / `primary-foreground`	Primary actions, CTAs	`bg-primary`, `text-primary-foreground`
`secondary` / `secondary-foreground`	Secondary actions	`bg-secondary`, `text-secondary-foreground`
`muted` / `muted-foreground`	Subdued backgrounds, secondary text	`bg-muted`, `text-muted-foreground`
`accent` / `accent-foreground`	Highlights, hover states	`bg-accent`, `text-accent-foreground`
`destructive` / `destructive-foreground`	Danger, delete actions	`bg-destructive`, `text-destructive`
`border`	Default border color	`border-border`
`input`	Form input borders	`border-input`
`ring`	Focus rings	`ring-ring`

Sidebar Colors

Within sidebar components: sidebar, sidebar-foreground, sidebar-primary, sidebar-accent, sidebar-border, sidebar-ring

Chart Colors

For data visualization: chart-1 through chart-5

Styling Patterns

Semantic Over Raw Colors

// GOOD - uses semantic colors, works with dark mode
className="bg-card border-border text-muted-foreground hover:bg-accent"

// AVOID - hardcoded colors don't adapt to theme
className="bg-white border-gray-200 text-gray-500 hover:bg-gray-100"

Opacity Modifiers

Use /opacity syntax (NOT deprecated bg-opacity-*):

className="bg-primary/50 border-border/30 text-foreground/80"

Common Component Patterns

Button:

className="bg-primary text-primary-foreground hover:bg-primary/90 focus-visible:ring-2 focus-visible:ring-ring"

Interactive Card:

className="bg-card border border-border hover:border-primary/50 hover:bg-accent/50 transition-colors"

Navigation Item:

className={isActive
  ? "bg-accent text-accent-foreground"
  : "text-muted-foreground hover:text-foreground hover:bg-accent/50"
}

Status Badges:

// Success
className="bg-green-500/10 text-green-600 border-green-500/30"
// Warning
className="bg-yellow-500/10 text-yellow-600 border-yellow-500/30"
// Info
className="bg-blue-500/10 text-blue-600 border-blue-500/30"

Tailwind v4 Specifics

Deprecated Patterns to Avoid

Deprecated	Use Instead
`@tailwind base/components/utilities`	`@import "tailwindcss"`
`bg-opacity-50`	`bg-color/50`
`text-opacity-50`	`text-color/50`
`flex-grow` / `flex-shrink`	`grow` / `shrink`
`shadow-sm`	`shadow-xs`
`rounded-sm`	`rounded-xs`
`bg-gradient-*`	`bg-linear-*`
`@layer utilities`	`@utility`

v4 Features

Container Queries:

<div className="@container">
  <div className="p-4 @lg:p-8 @xl:grid-cols-2">

3D Transforms:

className="perspective-1000 rotate-x-12 transform-3d"

Enhanced Gradients:

className="bg-linear-45 from-primary to-accent"
className="bg-radial from-primary via-secondary to-accent"

New Variants:

className="@starting-style:opacity-0 opacity-100 transition-opacity"
className="not-hover:opacity-50"
className="nth-odd:bg-muted"

Border Radius

Project-defined computed values:

rounded-sm = calc(var(--radius) - 4px)
rounded-md = calc(var(--radius) - 2px)
rounded-lg = var(--radius) (0.625rem)
rounded-xl = calc(var(--radius) + 4px)

Dark Mode

Dark mode uses .dark class on parent. Semantic colors auto-adapt—no dark: variants needed:

// Works in both light and dark mode automatically
className="bg-background text-foreground border-border"

Reference Files

Theme configuration: src/styles.css
Complete utility reference: UTILITIES.md

tailwind-v4

Tailwind CSS v4 Styling

Project Color System

Core Semantic Tokens