docs(10_Wiki): Dev 폴더 누락분 반영 — Topic_Programming으로 통합
이전 재구성 작업에서 Dev/ 폴더가 누락되었던 것을 반영. - Dev/Topic_Programming(중첩 폴더, 78개)은 Dev 자체 최상위 폴더들 (Architecture/Conventions/Engineering_Intelligence 등)과 완전 중복이라 제거. - Dev 최상위 엔지니어링 지식 폴더(Architecture/Conventions/Engineering_Intelligence/ Failure_Library/Generalized_Principles/Language/Pattern_Catalog/Platform_Guides/ Subsystems, 77개)는 이미 Topic_Programming/Topic_Programming에 더 최신 버전이 존재해 중복 제거(고유 콘텐츠 1개는 예외 처리하여 이동 보존). - Dev의 W3Schools 언어 튜토리얼 폴더(Topic_C/CPP/CSS/CSharp/HOWTO/HTML/Java/ JavaScript/PHP/Python/SQL/W3CSS, 1201개)는 전부 Topic_Programming 하위로 이동. - 에이전트 운영 상태(.astra/docs)는 그대로 유지, 콘텐츠 폴더만 정리. - Topic_Programming 최종 문서 수: 2784 → 3985.
This commit is contained in:
Antigravity Agent
@@ -0,0 +1,136 @@
|
||||
---
|
||||
id: css-relative-units
|
||||
title: "CSS Relative Units"
|
||||
category: "Frontend"
|
||||
status: "draft"
|
||||
verification_status: "conceptual"
|
||||
canonical_id: ""
|
||||
aliases: ["CSS relative units", "em rem", "viewport units", "vw vh", "scalable units"]
|
||||
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", "units", "relative", "responsive"]
|
||||
raw_sources: ["https://www.w3schools.com/css/css_units_relative.asp"]
|
||||
applied_in: []
|
||||
github_commit: ""
|
||||
---
|
||||
|
||||
# [[CSS Relative Units]]
|
||||
|
||||
## 🎯 한 줄 통찰 (One-line insight)
|
||||
Relative units specify a length relative to another length property — a parent element, the root element, or the viewport — so they scale better across different screen sizes, making `em` and `rem` ideal for scalable, responsive websites. [S1]
|
||||
|
||||
## 🧠 핵심 개념 (Core concepts)
|
||||
- **Relative to another length** — relative units specify a length relative to another length property (parent element, root element, or viewport). [S1]
|
||||
- **Better scaling** — relative length units scale better between different screen sizes. [S1]
|
||||
- **`em`** — relative to the font-size of the parent element. [S1]
|
||||
- **`rem`** — relative to the font-size of the root HTML element. [S1]
|
||||
- **Viewport units** — `vw`/`vh` are relative to 1% of viewport width/height (100vw = full width, 100vh = full height); `vmin`/`vmax` to 1% of the viewport's smaller/larger dimension. [S1]
|
||||
- **`%`, `fr`, `ch`** — `%` is relative to the parent's size; `fr` is a fractional unit (1fr = 1 part of available space); `ch` is relative to the width of the "0" (zero) character. [S1]
|
||||
|
||||
## 🧩 추출된 패턴 (Extracted patterns)
|
||||
- **`em` chains to the parent** — child sizes multiply against the parent's font-size, so nested `em` values compound. [S1]
|
||||
- **`rem` anchors to the root** — `rem` always references the root element, giving consistent sizing independent of nesting. [S1]
|
||||
|
||||
## 📖 세부 내용 (Details)
|
||||
**Relative Units**
|
||||
Relative units specify a length relative to another length property (like parent element, root element, or viewport). Relative length units scale better between different screen sizes. [S1]
|
||||
|
||||
| Unit | Description |
|
||||
| --- | --- |
|
||||
| `em` | Relative to the font-size of the parent element [S1] |
|
||||
| `rem` | Relative to the font-size of the root HTML element [S1] |
|
||||
| `vw` | Relative to 1% of the width of the viewport; 100vw = full width [S1] |
|
||||
| `vh` | Relative to 1% of the height of the viewport; 100vh = full height [S1] |
|
||||
| `vmin` | Relative to 1% of the viewport's smaller dimension [S1] |
|
||||
| `vmax` | Relative to 1% of the viewport's larger dimension [S1] |
|
||||
| `%` | Relative to the size of the parent element [S1] |
|
||||
| `fr` | A fractional unit; 1fr equals 1 part of the available space [S1] |
|
||||
| `ch` | Relative to the width of the "0" (zero) character [S1] |
|
||||
|
||||
**Em Font Sizing**
|
||||
Set font sizes with `em` (relative to the parent's font-size; with a 16px base, 2.5em = 40px): [S1]
|
||||
```css
|
||||
body {
|
||||
font-size: 16px; /* Base font size */
|
||||
}
|
||||
|
||||
h1 {
|
||||
font-size: 2.5em; /* 2.5 * 16 = 40px */
|
||||
}
|
||||
|
||||
h2 {
|
||||
font-size: 1.875em; /* 1.875 * 16 = 30px */
|
||||
}
|
||||
|
||||
p {
|
||||
font-size: 1em; /* 1 * 16 = 16px */
|
||||
}
|
||||
```
|
||||
|
||||
**Rem Font Sizing**
|
||||
Set font sizes with `rem` (relative to the root element rather than the parent, giving more consistent results): [S1]
|
||||
```css
|
||||
html {
|
||||
font-size: 16px; /* Set the root font size */
|
||||
}
|
||||
|
||||
h1 {
|
||||
font-size: 2.5rem; /* 2.5 * 16 = 40px */
|
||||
}
|
||||
|
||||
h2 {
|
||||
font-size: 1.875rem; /* 1.875 * 16 = 30px */
|
||||
}
|
||||
|
||||
p {
|
||||
font-size: 1rem; /* 1 * 16 = 16px */
|
||||
}
|
||||
```
|
||||
|
||||
**Tip:** The `em` and `rem` units are perfect for creating scalable and responsive websites! [S1]
|
||||
|
||||
## 🛠️ 적용 사례 (Applied in summary)
|
||||
The page's applied cases are the `em` and `rem` font-sizing examples, each computing `h1`/`h2`/`p` sizes from a 16px base. No external project/commit applications found in the source.
|
||||
|
||||
## 💻 코드 패턴 (Code patterns)
|
||||
em sizing relative to parent (language: CSS):
|
||||
```css
|
||||
body { font-size: 16px; }
|
||||
h1 { font-size: 2.5em; } /* 40px */
|
||||
```
|
||||
rem sizing relative to root (language: CSS):
|
||||
```css
|
||||
html { font-size: 16px; }
|
||||
h1 { font-size: 2.5rem; } /* 40px */
|
||||
```
|
||||
|
||||
## ⚖️ 비교 및 선택 기준 (Comparison & decision criteria)
|
||||
- **`em`** — relative to the parent element's font-size, so nested values compound; use when sizing should respond to the local context. [S1]
|
||||
- **`rem`** — relative to the root element's font-size, giving consistent results regardless of nesting; use for predictable global scaling. [S1]
|
||||
- **Viewport units (`vw`/`vh`/`vmin`/`vmax`)** — size relative to the viewport for full-screen-aware layouts. [S1]
|
||||
|
||||
## ⚖️ 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 Units]], [[CSS Absolute Units]], [[CSS Font Size]]
|
||||
- **참조 맥락:** Referenced when building scalable, responsive sizing that adapts to parent, root, or viewport.
|
||||
|
||||
## 📚 출처 (Sources)
|
||||
- [S1] W3Schools — CSS Relative Units — https://www.w3schools.com/css/css_units_relative.asp
|
||||
|
||||
## 📝 변경 이력 (Change history)
|
||||
- 2026-06-23: Initial draft synthesized from the W3Schools "CSS Relative Units" page (Astra wiki-curation, P-Reinforce v3.1 format).
|
||||
Reference in New Issue
Block a user