2nd/10_Wiki/Topic_CSS/CSS_Vertical_Align.md

id, title, category, status, verification_status, canonical_id, aliases, duplicate_of, source_trust_level, confidence_score, created_at, updated_at, review_reason, merge_history, tags, raw_sources, applied_in, github_commit

id	title	category	status	verification_status	canonical_id	aliases	duplicate_of	source_trust_level	confidence_score	created_at	updated_at	review_reason	merge_history	tags	raw_sources	applied_in	github_commit
css-vertical-align	CSS Vertical Align	Frontend	draft	conceptual		vertical align vertical centering flexbox center grid place-items transform translate center		B	0.89	2026-06-23	2026-06-23			css web frontend w3schools alignment flexbox grid	https://www.w3schools.com/css/css_align_vertical.asp

CSS Vertical Align

🎯 한 줄 통찰 (One-line insight)

Modern CSS centers content vertically with three approaches — Flexbox (align-items: center), Grid (place-items: center), or Position + Transform (top/left: 50% with translate(-50%, -50%)) — the last being the common technique for elements of unknown or dynamic dimensions. [S1]

🧠 핵심 개념 (Core concepts)

• Flexbox vertical centering — display: flex with justify-content: center and align-items: center centers content within a sized container. [S1]
• Grid vertical centering — display: grid with place-items: center achieves the same centering effect. [S1]
• Position + Transform — position: absolute with top: 50%, left: 50%, and transform: translate(-50%, -50%) centers content. [S1]
• Use Position + Transform for unknown sizes — it is a common technique when dealing with elements of unknown or dynamic dimensions. [S1]
• Container setup — the examples use a 200px-height container with a 3px solid green border. [S1]

🧩 추출된 패턴 (Extracted patterns)

• Flexbox both-axis center — display: flex; justify-content: center; align-items: center;. [S1]
• Grid one-liner center — display: grid; place-items: center;. [S1]
• Translate -50% center — absolutely position the child at 50%/50% then pull it back by half its own size with translate(-50%, -50%). [S1]

📖 세부 내용 (Details)

Center Align with Flexbox [S1]

.center {
  display: flex;
  justify-content: center;
  align-items: center;
  height: 200px;
  border: 3px solid green;
}

Center Align with Grid [S1]

.center {
  display: grid;
  place-items: center;
  height: 200px;
  border: 3px solid green;
}

Center Align with position and transform For elements of unknown or dynamic dimensions, this is a common technique. The example sets margin: 0 on the paragraph and centers it: [S1]

.container p {
  margin: 0;
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
}

The page directs readers to the 2D Transforms chapter for a deeper understanding of the transform property. [S1]

🛠️ 적용 사례 (Applied in summary)

The page's own applied examples are vertically centering content with Flexbox, with Grid (place-items), and with Position + Transform inside a 200px-height bordered container. No external project/commit applications found in the source.

💻 코드 패턴 (Code patterns)

Position + transform centering (language: CSS):

.container p {
  margin: 0;
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
}

⚖️ 비교 및 선택 기준 (Comparison & decision criteria)

• Flexbox vs Grid vs Position+Transform — Flexbox and Grid are modern container-driven techniques for vertical centering; Position + Transform is the common choice when the element has unknown or dynamic dimensions because translate(-50%, -50%) offsets by the element's own measured size. [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: 0.89
• 중복 검사 결과: 신규 생성 (New discovery)

🔗 지식 그래프 (Knowledge Graph)

• 상위/루트: CSS Tutorial
• 관련 개념: CSS Center Align, CSS Horizontal Align, CSS Flexbox, CSS Grid
• 참조 맥락: Referenced when vertically centering content, especially elements whose height is not known in advance.

📚 출처 (Sources)

• [S1] W3Schools — CSS Vertical Align — https://www.w3schools.com/css/css_align_vertical.asp

📝 변경 이력 (Change history)

• 2026-06-23: Initial draft synthesized from the W3Schools "CSS Vertical Align" page (Astra wiki-curation, P-Reinforce v3.1 format).