---
id: wiki-2026-0508-styled-components
title: Styled Components
category: 10_Wiki/Topics
status: verified
canonical_id: self
aliases: [styled-components, CSS-in-JS]
duplicate_of: none
source_trust_level: A
confidence_score: 0.9
verification_status: applied
tags: [react, css-in-js, frontend, styling]
raw_sources: []
last_reinforced: 2026-05-10
github_commit: pending
tech_stack:
  language: typescript
  framework: react
---

# Styled Components

## 매 한 줄
> **"매 CSS 의 component 의 안에 — 매 tagged template literal 로 매 React component + style 의 atomic unit"**. Glen Maddern, Max Stoiber (2016). 매 CSS-in-JS 의 reference. 2026 매 styled-components v6+ 가 매 React Server Components 의 partial 지원 — 매 RSC native era 에서 매 Tailwind / vanilla-extract / CSS Modules 의 challenge.

## 매 핵심

### 매 mechanic
- 매 tagged template literal: ``styled.button`color: red```.
- 매 runtime 의 unique class name 의 generation, 매 stylesheet 의 inject.
- 매 props-based dynamic styling: ``${props => props.primary ? '#0070f3' : '#fff'}``.

### 매 features
- **Theming**: ThemeProvider context.
- **`as` prop**: 매 polymorphic element.
- **Extending**: ``styled(Button)`...```.
- **Animations**: keyframes helper.
- **Global styles**: createGlobalStyle.

### 매 응용
1. React design system (Material-like component lib).
2. Theme switcher (dark mode).
3. Per-component style isolation.

## 💻 패턴

### Basic styled component (TypeScript)
```tsx
import styled from "styled-components";

const Button = styled.button<{ $primary?: boolean }>`
  padding: 8px 16px;
  border-radius: 6px;
  border: none;
  cursor: pointer;
  background: ${(p) => (p.$primary ? "#0070f3" : "#eee")};
  color: ${(p) => (p.$primary ? "#fff" : "#222")};
  &:hover { opacity: 0.9; }
`;

export default function App() {
  return <Button $primary>Buy</Button>;
}
```

### Theme + ThemeProvider
```tsx
import { ThemeProvider, DefaultTheme } from "styled-components";

const dark: DefaultTheme = { bg: "#111", fg: "#eee", accent: "#0af" };
const light: DefaultTheme = { bg: "#fff", fg: "#111", accent: "#06c" };

const Card = styled.div`
  background: ${(p) => p.theme.bg};
  color: ${(p) => p.theme.fg};
  padding: 16px;
`;

export default function App() {
  const [mode, setMode] = useState<"light" | "dark">("dark");
  return (
    <ThemeProvider theme={mode === "dark" ? dark : light}>
      <Card>Hello</Card>
    </ThemeProvider>
  );
}
```

### Extending another styled component
```tsx
const Base = styled.button`padding: 8px; border-radius: 4px;`;
const Danger = styled(Base)`background: #e00; color: white;`;
```

### `as` polymorphic prop
```tsx
const Box = styled.div`padding: 16px;`;
<Box as="section" /> // renders <section>
<Box as={Link} to="/x" /> // renders react-router Link
```

### Keyframes animation
```tsx
import styled, { keyframes } from "styled-components";
const pulse = keyframes`
  0% { transform: scale(1); }
  50% { transform: scale(1.1); }
  100% { transform: scale(1); }
`;
const Pulser = styled.div`animation: ${pulse} 1s infinite;`;
```

### Global styles
```tsx
import { createGlobalStyle } from "styled-components";
const Global = createGlobalStyle`
  body { margin: 0; font-family: Inter, sans-serif; background: ${(p) => p.theme.bg}; }
`;
```

### css helper for shared mixin
```tsx
import { css } from "styled-components";
const truncate = css`
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
`;
const Title = styled.h2`${truncate} font-size: 24px;`;
```

### Next.js 14+ App Router (RSC) — 매 'use client'
```tsx
"use client";
import styled from "styled-components";
export const Button = styled.button`color: red;`;
```

```tsx
// app/layout.tsx — registry pattern for SSR
import StyledRegistry from "./StyledRegistry";
export default function Root({ children }) {
  return <html><body><StyledRegistry>{children}</StyledRegistry></body></html>;
}
```

## 매 결정 기준
| 상황 | Approach |
|---|---|
| React SPA, 매 dynamic theming heavy | styled-components / emotion |
| React Server Components 의 native | vanilla-extract / CSS Modules / Tailwind |
| Utility-first, design system | Tailwind CSS v4 |
| Build-time zero-runtime | vanilla-extract / Linaria |
| Component lib for distribution | CSS Modules + tokens |

**기본값** (2026): 매 새 React project — Tailwind 의 default. styled-components 의 dynamic + theme heavy app 에 still-valid.

## 🔗 Graph
- 부모: [[CSS_Architecture_and_Styling|CSS-in-JS]] · [[React]]
- 변형: [[Vanilla Extract]]
- 응용: [[Design System]] · [[Theme Switching]]
- Adjacent: [[CSS_Architecture_and_Styling|Tailwind CSS]] · [[CSS Modules]] · [[React Server Components]]

## 🤖 LLM 활용
**언제**: dynamic prop-based styles 의 heavy, theme switching 의 first-class, existing CSS-in-JS app.
**언제 X**: 매 RSC-first new app — runtime cost + 'use client' boundary 의 friction. 매 Tailwind / vanilla-extract 의 prefer.

## ❌ 안티패턴
- **Inline style prop interpolation 의 every render**: 매 className thrash 의 perf hit. 매 attrs / static class 의 사용.
- **No `$` prefix on props**: 매 DOM warning (unknown attribute). 매 transient prop 의 사용 — `$primary`.
- **createGlobalStyle 의 multiple instances**: 매 conflict.
- **SSR without registry**: 매 FOUC. Next.js registry 의 setup.

## 🧪 검증 / 중복
- Verified (styled-components.com docs v6, 2025; Next.js 14 App Router CSS-in-JS guide).
- 신뢰도 A.

## 🕓 Changelog
| 날짜 | 변경 |
|---|---|
| 2026-05-08 | Phase 1 |
| 2026-05-10 | Manual cleanup — styled-components v6 + RSC era guidance |
