2nd/10_Wiki/Topic_CSS/CSS_Gradients_Radial.md

---
id: css-radial-gradients
title: "CSS Radial Gradients"
category: "Frontend"
status: "draft"
verification_status: "conceptual"
canonical_id: ""
aliases: ["radial-gradient", "CSS radial gradient", "repeating-radial-gradient", "circle gradient", "ellipse gradient"]
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", "gradients", "radial-gradient", "background-image"]
raw_sources: ["https://www.w3schools.com/css/css3_gradients_radial.asp"]
applied_in: []
github_commit: ""
---

# [[CSS Radial Gradients]]

## 🎯 한 줄 통찰 (One-line insight)
A radial gradient (`radial-gradient()`) is defined by its center and spreads color stops outward; by default it is an ellipse, sized `farthest-corner`, centered, and it is applied through the `background-image` property. [S1]

## 🧠 핵심 개념 (Core concepts)
- **Radial = defined by a center point** — a radial gradient is defined by its center and radiates the color transition outward. [S1]
- **At least two color stops** — like a linear gradient, a radial gradient must have at least two color stops. [S1]
- **Default shape, size, and position** — the defaults are shape = `ellipse`, size = `farthest-corner`, position = `center`. [S1]
- **Color-stop spacing** — color stops can be evenly spaced (the default) or assigned percentages to space them differently. [S1]
- **Shape and size are controllable** — shape can be `circle` or `ellipse`, and size keywords control how far the gradient extends. [S1]

## 🧩 추출된 패턴 (Extracted patterns)
- **Even-stops pattern** — `radial-gradient(color1, color2, color3)` for default evenly spaced stops. [S1]
- **Spaced-stops pattern** — assign percentages (`color 5%`, `color 15%`...) to control stop placement. [S1]
- **Shape pattern** — prepend `circle` (or `ellipse`) to force the shape. [S1]
- **Size-keyword pattern** — use `closest-side`/`farthest-side`/`closest-corner`/`farthest-corner` plus `at <position>` to control extent and center. [S1]
- **Repeating pattern** — `repeating-radial-gradient()` repeats a percentage-defined sequence. [S1]

## 📖 세부 내용 (Details)
**Syntax** [S1]
```
background-image: radial-gradient(shape size at position, start-color, ..., last-color);
```
By default the shape is `ellipse`, the size is `farthest-corner`, and the position is `center`.

**Evenly Spaced Color Stops (this is default)** [S1]
```css
#grad {
  background-image: radial-gradient(red, yellow, green);
}
```

**Differently Spaced Color Stops** [S1]
```css
#grad {
  background-image: radial-gradient(red 5%, yellow 15%, green 60%);
}
```

**Set Shape** [S1]
The shape parameter defines the shape. It can take the value `circle` or `ellipse`; the default value is `ellipse`. This example uses `circle`:
```css
#grad {
  background-image: radial-gradient(circle, red, yellow, green);
}
```

**Use of Different Size Keywords** [S1]
The size parameter defines the size of the gradient. It can take four values: `closest-side`, `farthest-side`, `closest-corner`, and `farthest-corner`.
```css
#grad1 {
  background-image: radial-gradient(closest-side at 70% 60%, red, yellow, black);
}

#grad2 {
  background-image: radial-gradient(farthest-side at 70% 60%, red, yellow, black);
}
```

**Repeating a radial-gradient** [S1]
The `repeating-radial-gradient()` function is used to repeat radial gradients.
```css
#grad {
  background-image: repeating-radial-gradient(red, yellow 10%, green 15%);
}
```

## 🛠️ 적용 사례 (Applied in summary)
The page's own demonstrations (the `#grad`, `#grad1`, and `#grad2` elements showing even/spaced stops, circle shape, size keywords, and repeating gradients) serve as the applied examples. No external project/commit applications found in the source.

## 💻 코드 패턴 (Code patterns)
Default radial gradient (language: CSS):
```css
#grad {
  background-image: radial-gradient(red, yellow, green);
}
```
Circle with positioned size keyword:
```css
#grad1 {
  background-image: radial-gradient(closest-side at 70% 60%, red, yellow, black);
}
```
Repeating radial gradient:
```css
#grad {
  background-image: repeating-radial-gradient(red, yellow 10%, green 15%);
}
```

## ⚖️ 비교 및 선택 기준 (Comparison & decision criteria)
- **`circle` vs `ellipse`** — `ellipse` is the default and stretches to the box's aspect ratio; choose `circle` when a perfectly round transition is wanted. [S1]
- **Size keywords** — `closest-side`, `farthest-side`, `closest-corner`, and `farthest-corner` decide where the gradient's ending shape meets the box; `farthest-corner` is the default. [S1]
- **Even vs differently spaced stops** — omit percentages for evenly spaced stops; supply percentages to bias where each color sits. [S1]
- **Single vs repeating** — use `repeating-radial-gradient()` when the percentage sequence should tile outward. [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:** 0.90
- **중복 검사 결과:** 신규 생성 (New discovery)

## 🔗 지식 그래프 (Knowledge Graph)
- **상위/루트:** [[CSS Tutorial]]
- **관련 개념:** [[CSS Linear Gradients]], [[CSS Conic Gradients]], [[CSS Box Shadow]]
- **참조 맥락:** Referenced whenever a center-out color background (spotlight/glow effect) is needed via `background-image`.

## 📚 출처 (Sources)
- [S1] W3Schools — CSS Radial Gradients — https://www.w3schools.com/css/css3_gradients_radial.asp

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