2nd/10_Wiki/Topic_CSS/CSS_Tooltip_Arrows.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-tooltip-arrows	CSS Tooltip Arrows	Frontend	draft	conceptual		tooltip arrow tooltip pointer speech bubble tooltip tooltip caret arrow tooltip		B	0.88	2026-06-23	2026-06-23			css web frontend w3schools tooltip pseudo-element	https://www.w3schools.com/css/css_tooltip_arrows.asp

CSS Tooltip Arrows

🎯 한 줄 통찰 (One-line insight)

A tooltip arrow is drawn with the ::after pseudo-element using the border trick — one border side is colored and the others are transparent — giving the tooltip a "speech bubble" look. [S1]

🧠 핵심 개념 (Core concepts)

• Pseudo-element arrow — the arrow is created with the ::after pseudo-element and a content property. [S1]
• Border trick — setting one side of the border to a color while the other three sides are transparent produces a triangular arrow. [S1]
• Positioning — the arrow is absolutely positioned relative to the tooltip; top: 100% places it at the bottom of the tooltip and left: 50% centers it horizontally. [S1]
• Size and centering — border-width controls the arrow size, and a margin of half that width (e.g. margin-left: -5px for border-width: 5px) keeps it centered. [S1]

🧩 추출된 패턴 (Extracted patterns)

• Four-direction arrow pattern — the arrow points down, up, right, or left depending on which border side is colored and where the pseudo-element is anchored (top/bottom vs left/right at 100%). [S1]
• Color-on-one-side rule — border-color takes four values (top right bottom left); coloring exactly one and leaving the rest transparent yields a single triangle. [S1]

📖 세부 내용 (Details)

How tooltip arrows work To create an arrow that appears like a speech bubble, add the ::after pseudo-element with the content property to the tooltip. The arrow itself is made with borders: when combined with the content, the entire tooltip becomes a speech bubble. [S1]

Positioning principle Position the arrow inside the tooltip: top: 100% will place the arrow at the bottom of the tooltip, and left: 50% will center the arrow. The border-width property specifies the size of the arrow; if you change this, also change the margin value so the arrow stays centered. The border-color is used to turn the content into an arrow — set the relevant side to the tooltip's background color and the rest to transparent. [S1]

Bottom arrow (arrow points down, tooltip above the trigger):

.tooltiptext::after {
  content: " ";
  position: absolute;
  top: 100%;
  left: 50%;
  margin-left: -5px;
  border-width: 5px;
  border-style: solid;
  border-color: black transparent transparent transparent;
}

Top arrow (arrow points up, tooltip below the trigger):

.tooltiptext::after {
  content: " ";
  position: absolute;
  bottom: 100%;
  left: 50%;
  margin-left: -5px;
  border-width: 5px;
  border-style: solid;
  border-color: transparent transparent black transparent;
}

Left arrow (arrow points left, tooltip to the right of the trigger):

.tooltiptext::after {
  content: " ";
  position: absolute;
  top: 50%;
  right: 100%;
  margin-top: -5px;
  border-width: 5px;
  border-style: solid;
  border-color: transparent black transparent transparent;
}

Right arrow (arrow points right, tooltip to the left of the trigger):

.tooltiptext::after {
  content: " ";
  position: absolute;
  top: 50%;
  left: 100%;
  margin-top: -5px;
  border-width: 5px;
  border-style: solid;
  border-color: transparent transparent transparent black;
}

🛠️ 적용 사례 (Applied in summary)

The four ::after rules above are the source's applied examples, each extending a positioned tooltip with a directional arrow. No external project/commit applications found in the source.

💻 코드 패턴 (Code patterns)

Generic arrow-via-border pattern (language: CSS):

.tooltiptext::after {
  content: " ";
  position: absolute;
  border-width: 5px;
  border-style: solid;
  /* color exactly one side; the others transparent */
  border-color: black transparent transparent transparent;
}

⚖️ 비교 및 선택 기준 (Comparison & decision criteria)

The four arrow variants differ only in two choices: (1) the anchor edge of the ::after element — top: 100% (bottom arrow), bottom: 100% (top arrow), right: 100% (left arrow), left: 100% (right arrow) — and (2) which border-color side is opaque. Choose the direction so the arrow points toward the trigger, matching the tooltip's own placement from CSS Tooltips. Use margin-left to recenter horizontal-edge arrows and margin-top to recenter vertical-edge arrows. [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: 0.88
• 중복 검사 결과: 신규 생성 (New discovery)

🔗 지식 그래프 (Knowledge Graph)

• 상위/루트: CSS Tutorial
• 관련 개념: CSS Tooltips, CSS Pseudo-elements, CSS Border, CSS Position
• 참조 맥락: Referenced when a tooltip needs a visual pointer connecting it to its trigger element.

📚 출처 (Sources)

• [S1] W3Schools — CSS Tooltip Arrows — https://www.w3schools.com/css/css_tooltip_arrows.asp

📝 변경 이력 (Change history)

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