---
id: css-rounded-borders
title: "CSS Rounded Borders"
category: "Frontend"
status: "draft"
verification_status: "conceptual"
canonical_id: ""
aliases: ["border-radius", "CSS rounded borders", "rounded corners", "round border", "corner radius"]
duplicate_of: ""
source_trust_level: "B"
confidence_score: 0.86
created_at: 2026-06-23
updated_at: 2026-06-23
review_reason: ""
merge_history: []
tags: ["css", "web", "frontend", "w3schools", "border", "border-radius"]
raw_sources: ["https://www.w3schools.com/css/css_border_rounded.asp"]
applied_in: []
github_commit: ""
---

# [[CSS Rounded Borders]]

## 🎯 한 줄 통찰 (One-line insight)
The `border-radius` property is used to add rounded corners to an element, with larger radius values producing rounder corners. [S1]

## 🧠 핵심 개념 (Core concepts)
- **`border-radius`** is used to add rounded borders to an element. [S1]
- **Visual progression** — the page demonstrates corners ranging from a normal (square) border through increasingly rounded variants ("Normal border", "Round border", "Rounder border", "Roundest border"). [S1]
- **Combined with a border** — rounded corners are shown applied on top of a defined border (e.g. `2px solid red`). [S1]

## 🧩 추출된 패턴 (Extracted patterns)
- **Border-plus-radius** — pair a `border` declaration with a `border-radius` value to round the corners of a bordered element. [S1]
- **Radius magnitude controls roundness** — increasing the radius value increases the visible corner curvature. [S1]

## 📖 세부 내용 (Details)
**CSS Rounded Borders** [S1]
The `border-radius` property is used to add rounded borders to an element.

**Example** — a paragraph with a solid red border and rounded corners: [S1]
```css
p {
  border: 2px solid red;
  border-radius: 5px;
}
```

The page visually shows several levels of rounding labelled "Normal border", "Round border", "Rounder border", and "Roundest border". The exact CSS source for each individual labelled variation (beyond the `5px` example above) was rendered as images in the page and is **Not found in source**. [S1]

## 🛠️ 적용 사례 (Applied in summary)
The page's own applied example is the single paragraph rule above, combining a `2px solid red` border with a `5px` `border-radius`. No external project/commit applications found in the source.

## 💻 코드 패턴 (Code patterns)
Rounded border on a bordered element (language: CSS):
```css
p {
  border: 2px solid red;
  border-radius: 5px;
}
```

## ⚖️ 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:** 0.86
- **중복 검사 결과:** 신규 생성 (New discovery)

## 🔗 지식 그래프 (Knowledge Graph)
- **상위/루트:** [[CSS Tutorial]]
- **관련 개념:** [[CSS Border Shorthand]], [[CSS Border Style]], [[CSS Border Width]], [[CSS Border Color]]
- **참조 맥락:** Applied on top of a defined border to soften an element's corners.

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

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