2nd/10_Wiki/Topic_CSS/CSS_Pseudo_Classes_Interactive.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-interactive-pseudo-classes	CSS Interactive Pseudo-classes	Frontend	draft	conceptual		interactive pseudo-classes link pseudo-classes hover focus active anchor states hover tooltip		B	0.88	2026-06-23	2026-06-23			css web frontend w3schools pseudo-classes links	https://www.w3schools.com/css/css_pseudo_classes_interactive.asp

CSS Interactive Pseudo-classes

🎯 한 줄 통찰 (One-line insight)

Interactive pseudo-classes style elements in response to user actions — the four link states (:link, :visited, :hover, :active) must be declared in a specific order, and :hover/:focus also power effects like tooltips and highlighted inputs. [S1]

🧠 핵심 개념 (Core concepts)

• Four link states — :link (unvisited), :visited (visited), :hover (mouseover), :active (when clicked/activated). [S1]
• Order matters — a:hover MUST come after a:link and a:visited to be effective; a:active MUST come after a:hover to be effective. [S1]
• :hover is not just for links — it can apply to any element, e.g. a <div>. [S1]
• :focus — styles a form input while it has focus. [S1]
• Hover-driven reveal — div:hover p can show a hidden paragraph, producing a simple tooltip effect. [S1]
• Combine with classes — pseudo-classes can be combined with HTML classes, e.g. a.highlight:hover. [S1]

🧩 추출된 패턴 (Extracted patterns)

• LVHA ordering — declare link, visited, hover, active in that cascade order so each rule takes effect. [S1]
• Hover-to-reveal — hide a child (display: none) and show it (display: block) on parent hover for a tooltip. [S1]
• Scoped hover — pair a class with :hover (a.highlight:hover) to limit the effect to selected elements. [S1]

📖 세부 내용 (Details)

Link pseudo-classes (the four states) Style links through different states using :link, :visited, :hover, and :active: [S1]

/* unvisited link */
a:link {
  color: #FF0000;
}

/* visited link */
a:visited {
  color: #00FF00;
}

/* mouse over link */
a:hover {
  color: #FF00FF;
}

/* selected link */
a:active {
  color: #0000FF;
}

Ordering note a:hover MUST come after a:link and a:visited in the CSS definition in order to be effective! a:active MUST come after a:hover in the CSS definition in order to be effective! [S1]

:hover on a div element [S1]

div:hover {
  background-color: blue;
}

Simple tooltip hover effect Hovering over a <div> reveals a hidden paragraph: [S1]

p {
  display: none;
  background-color: yellow;
  padding: 20px;
}

div:hover p {
  display: block;
}

:focus on an input element [S1]

input:focus {
  background-color: yellow;
}

Combining pseudo-classes with HTML classes [S1]

a.highlight:hover {
  color: #ff0000;
}

🛠️ 적용 사례 (Applied in summary)

The page's own applied examples are: coloring the four anchor link states, changing a div background on hover, a hover-reveal tooltip (div:hover p), highlighting a focused input, and a class-scoped hover (a.highlight:hover). No external project/commit applications found in the source.

💻 코드 패턴 (Code patterns)

Hover-to-reveal tooltip (language: CSS):

p {
  display: none;
}

div:hover p {
  display: block;
}

Class-scoped hover:

a.highlight:hover {
  color: #ff0000;
}

⚖️ 비교 및 선택 기준 (Comparison & decision criteria)

• :hover vs :active vs :focus — :hover reacts to the mouse being over an element, :active to the element being activated (e.g. clicked), and :focus to an element (typically a form field) holding focus. For links, all four states must follow the LVHA order to apply correctly. [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 Pseudo-classes, CSS Combinators, CSS Links, CSS Selectors
• 참조 맥락: Referenced when styling link states, hover/focus interactions, and hover-driven UI such as tooltips.

📚 출처 (Sources)

• [S1] W3Schools — CSS Interactive Pseudo-classes — https://www.w3schools.com/css/css_pseudo_classes_interactive.asp

📝 변경 이력 (Change history)

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