---
id: howto-css-mixed-columns
title: "How To - Mixed Column Layout"
category: "Web_Recipes"
status: "draft"
verification_status: "conceptual"
canonical_id: ""
aliases: ["responsive 4-2-1 column layout"]
duplicate_of: ""
source_trust_level: "B"
confidence_score: 0.83
created_at: 2026-07-04
updated_at: 2026-07-04
review_reason: ""
merge_history: []
tags: ["howto", "css", "w3schools", "layout", "float", "responsive", "media-queries"]
raw_sources: ["https://www.w3schools.com/howto/howto_css_mixed_columns.asp"]
applied_in: []
github_commit: ""
---

# [[HOWTO CSS Mixed Columns]]

## 🎯 한 줄 통찰 (One-line insight)
Where `[[HOWTO CSS Four Columns]]` collapsed directly from 4 columns to 1 stacked column at a single breakpoint, this recipe adds an INTERMEDIATE step — two STACKED media queries (900px, then 600px) progressively widen each column's percentage (25% → 50% → 100%) as the screen narrows, demonstrating that responsive breakpoints aren't limited to one "desktop vs. mobile" cutoff; they can chain to create a 4-column → 2-column → 1-column cascade, with each `@media` rule simply overriding the previous width at a narrower threshold. [S1]

## 🧠 핵심 개념 (Core concepts)
- **Base layout: 4 equal float columns** — `.column { float: left; width: 25%; }` plus the standard `.row:after` clearfix. [S1]
- **First breakpoint (900px): 4 → 2 columns** — `@media (max-width: 900px) { .column { width: 50%; } }`. [S1]
- **Second breakpoint (600px): 2 → 1 column** — `@media (max-width: 600px) { .column { width: 100%; } }`. [S1]
- **Cascading override order matters** — later (narrower) media queries must come after earlier (wider) ones in the stylesheet so they correctly override at smaller widths, per normal CSS cascade rules. [S1]

## 📖 세부 내용 (Details)
- Full progressive layout: `.column { float: left; width: 25%; } .row:after { content: ""; display: table; clear: both; } @media screen and (max-width: 900px) { .column { width: 50%; } } @media screen and (max-width: 600px) { .column { width: 100%; } }`. [S1]

## ⚖️ 모순 및 업데이트 (Contradictions & updates)
- **단일 브레이크포인트가 아니라 다단계 캐스케이드**: `[[HOWTO CSS Four Columns]]`는 600px 하나의 브레이크포인트로 4열→1열로 바로 붕괴시켰지만, 이 레시피는 900px(4→2열)과 600px(2→1열) 두 단계를 거치는 점진적 붕괴를 사용한다는 점이 확인됨 — 반응형 브레이크포인트가 여러 단계로 연쇄될 수 있음을 보여줌. [S1]

## 🛠️ 적용 사례 (Applied in summary)
화면 폭에 따라 4열→2열→1열로 점진적으로 바뀌는 컬럼 레이아웃 예제가 원문에서 직접 제시됨. [S1]

## 💻 코드 패턴 (Code patterns)
Progressive breakpoint cascade — 4 columns → 2 → 1 (CSS):
```css
.column { float: left; width: 25%; }

@media screen and (max-width: 900px) {
  .column { width: 50%; }
}
@media screen and (max-width: 600px) {
  .column { width: 100%; }
}
```

## ✅ 검증 상태 및 신뢰도
- **상태:** draft
- **검증 단계:** conceptual
- **출처 신뢰도:** B (W3Schools — widely used educational reference)
- **신뢰 점수:** 0.83
- **중복 검사 결과:** 신규 생성 (New discovery)

## 🔗 지식 그래프 (Knowledge Graph)
- **상위/루트:** [[W3Schools HOW TO]]
- **관련 개념:** [[HOWTO CSS Four Columns]], [[HOWTO CSS Responsive Floats]], [[HOWTO CSS Two Columns]]
- **참조 맥락:** CSS Layout & Positioning 섹션.

## 📚 출처 (Sources)
- [S1] W3Schools — How To - Mixed Column Layout — https://www.w3schools.com/howto/howto_css_mixed_columns.asp

## 📝 변경 이력 (Change history)
- 2026-07-04: Initial draft synthesized from the W3Schools "How To - Mixed Column Layout" recipe (Astra wiki-curation, P-Reinforce v3.1 format).