2nd/10_Wiki/Topics/Frontend/CSS Grid.md

---
id: wiki-2026-0508-css-grid
title: CSS Grid
category: 10_Wiki/Topics
status: verified
canonical_id: self
aliases: [Grid Layout, CSS Grid Layout]
duplicate_of: none
source_trust_level: A
confidence_score: 0.9
verification_status: applied
tags: [css, layout, frontend]
raw_sources: []
last_reinforced: 2026-05-10
github_commit: pending
tech_stack:
  language: css
  framework: none
---

# CSS Grid

## 매 한 줄
> **"매 2D layout 의 native primitive"**. CSS Grid 매 row + column 동시 control 의 layout system — 매 Flexbox 의 1D 보완. 매 2026 현재 매 모든 modern browser 매 stable, 매 `subgrid` + `masonry` (experimental) 까지 지원, 매 page-level 부터 component-level 까지 default tool.

## 매 핵심

### 매 모델
- **Grid container** (`display: grid`) — 매 parent.
- **Grid items** — 매 direct children, 매 line-based positioning.
- **Tracks** — rows + columns, 매 `fr` unit (fractional space) + `minmax()` + `auto`.
- **Areas** — 매 named regions, 매 semantic layout description.

### 매 vs Flexbox
- **Grid**: 매 2D (row + column 동시), 매 layout-first (parent decides).
- **Flexbox**: 매 1D (single axis), 매 content-first (children sizing).
- 매 함께 mix — 매 outer Grid + inner Flex 매 common.

### 매 응용
1. Page layout (header / sidebar / main / footer).
2. Card grid 매 responsive (`auto-fill` + `minmax`).
3. Dashboard 매 named-area complex layout.
4. Image gallery 매 masonry.

## 💻 패턴

### Holy Grail layout
```css
.layout {
  display: grid;
  grid-template-columns: 200px 1fr 200px;
  grid-template-rows: auto 1fr auto;
  grid-template-areas:
    "header header header"
    "nav    main   aside"
    "footer footer footer";
  min-height: 100vh;
}
.header { grid-area: header; }
.nav    { grid-area: nav; }
.main   { grid-area: main; }
.aside  { grid-area: aside; }
.footer { grid-area: footer; }
```

### Responsive card grid (`auto-fill`)
```css
.cards {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 16px;
}
```

### Subgrid (nested alignment)
```css
.outer {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
}
.card {
  display: grid;
  grid-template-rows: subgrid;  /* inherit parent row tracks */
  grid-row: span 3;
}
```

### Line-based placement
```css
.item {
  grid-column: 2 / span 3;  /* col 2 to 4 */
  grid-row: 1 / -1;          /* full height */
}
```

### Masonry (2026 experimental)
```css
.gallery {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
  grid-template-rows: masonry;  /* Firefox + Safari TP */
  gap: 8px;
}
```

### Implicit grid + `dense` packing
```css
.feed {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  grid-auto-flow: dense;       /* fill holes */
  grid-auto-rows: 100px;
}
.feed > .featured {
  grid-column: span 2;
  grid-row: span 2;
}
```

## 매 결정 기준
| 상황 | Approach |
|---|---|
| Page-level 2D layout | **Grid** |
| Component 매 1D row/column | Flex |
| Aligned nested grids | **Grid + subgrid** |
| Dynamic content count, fluid wrap | Grid `auto-fill` |
| Dense irregular packing | Grid `auto-flow: dense` |

**기본값**: 매 layout-first 결정 — Grid. 매 content-first sizing — Flex.

## 🔗 Graph
- 부모: [[Layout]]
- 변형: [[Flexbox]] · [[Subgrid]] · [[컨테이너 쿼리 (Container Queries)|Container Queries]]
- 응용: [[Responsive Design]]
- Adjacent: [[CSS Grid 및 Flexbox]]

## 🤖 LLM 활용
**언제**: 2D layout, named areas semantic intent, responsive 매 `auto-fill`.
**언제 X**: 1D 매 simple row of buttons — Flexbox 가 더 ergonomic.

## ❌ 안티패턴
- **모두 1D 에 Grid 매 사용**: 매 Flex 보다 verbose.
- **Pixel-only tracks**: 매 `fr` + `minmax` 매 사용 — 매 fluid.
- **`!important` 으로 children 매 overriding**: 매 grid-area 매 misaligned signal.
- **Subgrid 매 ignore**: nested grids 매 line-up 가 필요할 때 매 `subgrid` 가 정답.

## 🧪 검증 / 중복
- Verified (MDN CSS Grid Layout 2026, CSS Working Group Level 3).
- 신뢰도 A.

## 🕓 Changelog
| 날짜 | 변경 |
|---|---|
| 2026-05-08 | Phase 1 |
| 2026-05-10 | Manual cleanup — Grid 2D layout + subgrid + masonry + responsive patterns |