---
id: css-grouping-selectors
title: "CSS Grouping Selectors"
category: "Frontend"
status: "draft"
verification_status: "conceptual"
canonical_id: ""
aliases: ["grouping selector", "comma selector", "shared declarations", "universal selector", "CSS code minimization"]
duplicate_of: ""
source_trust_level: "B"
confidence_score: 0.88
created_at: 2026-06-23
updated_at: 2026-06-23
review_reason: ""
merge_history: []
tags: ["css", "web", "frontend", "w3schools", "selectors"]
raw_sources: ["https://www.w3schools.com/css/css_selectors_grouping.asp"]
applied_in: []
github_commit: ""
---

# [[CSS Grouping Selectors]]

## 🎯 한 줄 통찰 (One-line insight)
When several elements share identical style definitions, group their selectors with commas into a single rule to minimize code; the universal selector `*` applies a declaration to every element on the page. [S1]

## 🧠 핵심 개념 (Core concepts)
- **Universal selector** — `*` selects all HTML elements on the page. [S1]
- **Grouping selector** — selects all the HTML elements with the same style definitions. [S1]
- **Comma syntax** — to group selectors, separate each selector with a comma. [S1]
- **Benefit** — grouping minimizes code when multiple elements share identical style definitions. [S1]

## 🧩 추출된 패턴 (Extracted patterns)
- **Collapse duplicates** — replace several rules with identical declarations by one comma-separated selector list. [S1]
- **Whole-page baseline** — use `*` to apply a single declaration block to every element. [S1]

## 📖 세부 내용 (Details)
**The CSS universal selector** (`*`) selects all HTML elements on the page. [S1]
```css
* {
  text-align: center;
  color: blue;
}
```

**The CSS grouping selector** selects all the HTML elements with the same style definitions. [S1]

Look at the following CSS code (the `h1`, `h2`, and `p` elements have the same style definitions): [S1]
```css
h1 {
  text-align: center;
  color: red;
}

h2 {
  text-align: center;
  color: red;
}

p {
  text-align: center;
  color: red;
}
```

It will be better to group the selectors, to minimize the code. To group selectors, separate each selector with a comma. [S1]
```css
h1, h2, p {
  text-align: center;
  color: red;
}
```

## 🛠️ 적용 사례 (Applied in summary)
The page's own example groups `h1`, `h2`, and `p` — which originally carried three identical rules — into one comma-separated rule. No external project/commit applications found in the source.

## 💻 코드 패턴 (Code patterns)
Grouping selectors that share declarations (language: CSS):
```css
h1, h2, p {
  text-align: center;
  color: red;
}
```
Universal selector:
```css
* {
  text-align: center;
  color: blue;
}
```

## ⚖️ 모순 및 업데이트 (Contradictions & updates)
No contradictions found in the source.

## ✅ 검증 상태 및 신뢰도
- **상태:** draft
- **검증 단계:** conceptual (실제 적용 사례 발견 시 applied/validated로 승격 가능)
- **출처 신뢰도:** B (W3Schools — widely used educational reference, not a primary standards body)
- **신뢰 점수:** 0.88
- **중복 검사 결과:** 신규 생성 (New discovery)

## 🔗 지식 그래프 (Knowledge Graph)
- **상위/루트:** [[CSS Tutorial]]
- **관련 개념:** [[CSS Selectors]], [[CSS Syntax]], [[CSS Introduction]]
- **참조 맥락:** Referenced when reducing duplication across rules that share the same declarations.

## 📚 출처 (Sources)
- [S1] W3Schools — CSS Grouping Selectors — https://www.w3schools.com/css/css_selectors_grouping.asp

## 📝 변경 이력 (Change history)
- 2026-06-23: Initial draft synthesized from the W3Schools "CSS Grouping Selectors" page (Astra wiki-curation, P-Reinforce v3.1 format).
