koriweb
9609c04755
W3Schools 튜토리얼을 P-Reinforce v3.1 포맷으로 위키화(영어 본문, 한/영 섹션 헤더). - Topic_HTML: 59문서 (튜토리얼+예제, 레퍼런스/메타 제외) - Topic_CSS: 190문서 (메인 + Advanced/Flexbox/Grid/RWD 전체) - Topic_JavaScript: 120문서 (코어 언어; Temporal/DOM상세/BOM/WebAPI/AJAX/jQuery/Graphics 등은 후속) 각 폴더 00_INDEX.md(MOC) 포함. 코드 verbatim, 미확인분은 "Not found in source" 표기. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
102 lines
4.0 KiB
Markdown
102 lines
4.0 KiB
Markdown
---
|
|
id: css-pseudo-elements
|
|
title: "CSS Pseudo-elements"
|
|
category: "Frontend"
|
|
status: "draft"
|
|
verification_status: "conceptual"
|
|
canonical_id: ""
|
|
aliases: ["pseudo-elements", "::before", "::after", "::first-line", "::marker", "double-colon selectors"]
|
|
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", "pseudo-elements", "selectors"]
|
|
raw_sources: ["https://www.w3schools.com/css/css_pseudo_elements.asp"]
|
|
applied_in: []
|
|
github_commit: ""
|
|
---
|
|
|
|
# [[CSS Pseudo-elements]]
|
|
|
|
## 🎯 한 줄 통찰 (One-line insight)
|
|
A CSS pseudo-element is a keyword added to a selector that lets you style a specific part of an element — the first line, the first letter, inserted content, list markers, selected text, or a dialog backdrop. [S1]
|
|
|
|
## 🧠 핵심 개념 (Core concepts)
|
|
- **Definition** — A CSS pseudo-element is a keyword that can be added to a selector, to style a specific part of an element. [S1]
|
|
- **Double-colon syntax** — pseudo-elements are written with `::` after the selector. [S1]
|
|
- **Two families** — text pseudo-elements (`::first-line`, `::first-letter`) and content pseudo-elements (`::before`, `::after`, `::marker`, `::selection`, `::backdrop`). [S1]
|
|
|
|
## 🧩 추출된 패턴 (Extracted patterns)
|
|
- **Style a part, not the whole** — pseudo-elements address sub-parts of an element (a line, a letter, generated content) rather than the element as a whole. [S1]
|
|
- **Syntax pattern** — `selector::pseudo-element-name { CSS properties }`. [S1]
|
|
|
|
## 📖 세부 내용 (Details)
|
|
**Definition** [S1]
|
|
A CSS pseudo-element is a keyword that can be added to a selector, to style a specific part of an element. Common uses include:
|
|
- Styling the first letter or first line of an element
|
|
- Inserting content before or after an element
|
|
- Styling list item markers
|
|
- Styling user-selected portions of an element
|
|
- Styling the viewbox behind a dialog box
|
|
|
|
**Syntax** [S1]
|
|
```css
|
|
selector::pseudo-element-name {
|
|
CSS properties
|
|
}
|
|
```
|
|
|
|
**Text pseudo-elements** [S1]
|
|
|
|
| Pseudo-element | Description |
|
|
| --- | --- |
|
|
| `::first-line` | Style the first line of text |
|
|
| `::first-letter` | Style the first letter of text |
|
|
|
|
**Content pseudo-elements** [S1]
|
|
|
|
| Pseudo-element | Description |
|
|
| --- | --- |
|
|
| `::before` | Insert content before an element |
|
|
| `::after` | Insert content after an element |
|
|
| `::marker` | Style list item markers |
|
|
| `::selection` | Style user-selected text |
|
|
| `::backdrop` | Style dialog backdrop |
|
|
|
|
The source references a complete CSS Pseudo-elements Reference for the full list. [S1]
|
|
|
|
## 🛠️ 적용 사례 (Applied in summary)
|
|
This page is an overview/index; the detailed applied examples live on the dedicated text and content pseudo-element pages. No external project/commit applications found in the source.
|
|
|
|
## 💻 코드 패턴 (Code patterns)
|
|
Pseudo-element syntax (language: CSS):
|
|
```css
|
|
selector::pseudo-element-name {
|
|
CSS properties
|
|
}
|
|
```
|
|
|
|
## ⚖️ 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 Text Pseudo-elements]], [[CSS Content Pseudo-elements]], [[CSS Structural Pseudo-classes]]
|
|
- **참조 맥락:** The entry point whenever styling a specific part of an element rather than the whole.
|
|
|
|
## 📚 출처 (Sources)
|
|
- [S1] W3Schools — CSS Pseudo-elements — https://www.w3schools.com/css/css_pseudo_elements.asp
|
|
|
|
## 📝 변경 이력 (Change history)
|
|
- 2026-06-23: Initial draft synthesized from the W3Schools "CSS Pseudo-elements" page (Astra wiki-curation, P-Reinforce v3.1 format).
|