Split Button

Create a Split Button component for an AI-generated interface using shadcn-style composition. Use shadcn/ui button + dropdown-menu as the implementation base. The component should support default, muted, outline, ghost, destructive variants and default, hover, focus-visible, active, disabled, loading states. Include clear anatomy for Root, Label, Leading icon, Trailing icon, Loading indicator. Keep the visual language black, white, and gray with subtle borders, practical spacing, accessible focus states, and no decorative noise.

Do not invent a custom component API when shadcn/ui button + dropdown-menu already covers the base behavior. Avoid random gradients, oversized radii, unclear disabled states, missing labels, icon-only controls without accessible names, and variants that change layout unexpectedly.

Base: shadcn/ui button + dropdown-menu
Primitive: Radix Dropdown Menu
Tailwind: Use shadcn tokens for background, border, ring, muted text, radius, and state variants. Keep component-specific classes local and copyable.
Dependency: Use Radix Dropdown Menu through the matching shadcn component when possible.

{
  "id": "split-button",
  "category": "components",
  "trigger": "user interaction",
  "target": "split button",
  "feeling": [
    "polished",
    "practical",
    "precise"
  ],
  "palette": [
    "black",
    "white",
    "gray"
  ],
  "radius": "8px or less",
  "border": "1px solid rgba(237, 237, 236, 0.14)",
  "background": "neutral surface with subtle contrast",
  "foreground": "high-contrast text",
  "mutedForeground": "secondary text at 68-74% contrast",
  "focusRing": "2px neutral ring with offset",
  "shadow": "soft elevation only when interaction needs tactility",
  "motionDuration": "120ms-220ms"
}