2nd/10_Wiki/Topic_CSS/CSS_Margins.md

---
id: css-margins
title: "CSS Margins"
category: "Frontend"
status: "draft"
verification_status: "conceptual"
canonical_id: ""
aliases: ["margin", "CSS margins", "margin-top", "margin shorthand", "margin auto centering"]
duplicate_of: ""
source_trust_level: "B"
confidence_score: 0.9
created_at: 2026-06-23
updated_at: 2026-06-23
review_reason: ""
merge_history: []
tags: ["css", "web", "frontend", "w3schools", "margin", "box-model"]
raw_sources: ["https://www.w3schools.com/css/css_margin.asp"]
applied_in: []
github_commit: ""
---

# [[CSS Margins]]

## 🎯 한 줄 통찰 (One-line insight)
The CSS margin properties are used to create space around elements, outside of any defined borders — set individually per side, with the `margin` shorthand, with `auto` to horizontally center an element, or with `inherit` to take the parent's margin. [S1]

## 🧠 핵심 개념 (Core concepts)
- **Purpose** — margins are used to create space around elements, outside of any defined borders. [S1]
- **Full control** — CSS has properties for specifying the margin for each side of an element: `margin-top`, `margin-right`, `margin-bottom`, `margin-left`. [S1]
- **Allowed values:** `auto` — the browser calculates the margin; `length` — specifies a margin in px, pt, cm, etc.; `%` — specifies a margin in % of the width of the containing element; `inherit` — specifies that the margin should be inherited from the parent element. [S1]
- **Negative values** — negative values are allowed. [S1]
- **Shorthand** — the `margin` property is a shorthand for setting all four margins in one declaration with one to four values. [S1]

## 🧩 추출된 패턴 (Extracted patterns)
- **One-to-four value box model** — `margin` accepts 1/2/3/4 values mapping to all sides / vertical+horizontal / top+horizontal+bottom / clockwise per-side. [S1]
- **`margin: auto` centering** — set a width and `margin: auto` to horizontally center an element within its container. [S1]

## 📖 세부 내용 (Details)
**CSS Margins** [S1]
The CSS margin properties are used to create space around elements, outside of any defined borders. With CSS, you have full control over the margins.

**Margin - Individual Sides** [S1]
CSS has properties for specifying the margin for each side of an element:
- `margin-top`
- `margin-right`
- `margin-bottom`
- `margin-left`

All the margin properties can have the following values: [S1]

| Value | Meaning |
|-------|---------|
| `auto` | The browser calculates the margin |
| *length* | Specifies a margin in px, pt, cm, etc. |
| `%` | Specifies a margin in % of the width of the containing element |
| `inherit` | Specifies that the margin should be inherited from the parent element |

**Tip:** Negative values are allowed. [S1]

**Example** — setting each side individually: [S1]
```css
p {
  margin-top: 100px;
  margin-bottom: 100px;
  margin-right: 150px;
  margin-left: 80px;
}
```

**Margin - Shorthand Property** [S1]
To shorten the code, it is possible to specify all the margin properties in one property. The `margin` property is a shorthand property for the individual margin properties.

The number of values determines which sides they apply to: [S1]
- **four values** `margin: 25px 50px 75px 100px;` — top 25px, right 50px, bottom 75px, left 100px
- **three values** `margin: 25px 50px 75px;` — top 25px, right and left 50px, bottom 75px
- **two values** `margin: 25px 50px;` — top and bottom 25px, right and left 50px
- **one value** `margin: 25px;` — all four margins 25px

**Example** — shorthand with four values: [S1]
```css
p {
  margin: 25px 50px 75px 100px;
}
```

**The auto Value** [S1]
You can set the margin property to `auto` to horizontally center the element within its container. The element will then take up the specified width, and the remaining space will be split equally between the left and right margins.

**Example** — centering with `auto`: [S1]
```css
div {
  width: 300px;
  margin: auto;
  border: 1px solid red;
}
```

**The inherit Value** [S1]
This example lets the left margin of an element be inherited from the parent element.

**Example** — inheriting the left margin: [S1]
```css
div {
  border: 1px solid red;
  margin-left: 100px;
}

p.ex1 {
  margin-left: inherit;
}
```

## 🛠️ 적용 사례 (Applied in summary)
The page's own applied examples are the stylesheets above: per-side margins, the four-value shorthand, the `margin: auto` centering rule, and the `inherit` parent/child pair. No external project/commit applications found in the source.

## 💻 코드 패턴 (Code patterns)
Per-side margins (language: CSS):
```css
p {
  margin-top: 100px;
  margin-bottom: 100px;
  margin-right: 150px;
  margin-left: 80px;
}
```
Horizontal centering with auto:
```css
div {
  width: 300px;
  margin: auto;
  border: 1px solid red;
}
```

## ⚖️ 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:** 0.90
- **중복 검사 결과:** 신규 생성 (New discovery)

## 🔗 지식 그래프 (Knowledge Graph)
- **상위/루트:** [[CSS Tutorial]]
- **관련 개념:** [[CSS Margin Collapse]], [[CSS Border Shorthand]], [[CSS Border Sides]]
- **참조 맥락:** The outer spacing layer of the CSS box model; paired with borders and padding when laying out elements.

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

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