{
  "id": "motion:motion-sticky",
  "slug": "motion-sticky",
  "kind": "motion",
  "title": {
    "ja": "スティッキー",
    "en": "Sticky"
  },
  "aiName": "position: sticky",
  "summary": {
    "ja": "見出しが上に貼り付く",
    "en": "Headings stick to the top as you scroll"
  },
  "number": 17,
  "group": "pin-nav",
  "techniques": [
    "position-sticky"
  ],
  "rules": [
    {
      "ja": "見出しは自分の区画の中でだけ貼り付き、区画を越えて残らない",
      "en": "Each heading sticks only within its own section, never across sections"
    },
    {
      "ja": "見出しの背景は不透明にし、下の本文が透けないようにする",
      "en": "Headings have an opaque ground background so the content below does not show through"
    },
    {
      "ja": "動きを減らす設定では sticky を解除し、見出しを通常の流れで並べる",
      "en": "Under prefers-reduced-motion, turn sticky off and keep all headings in normal flow"
    }
  ],
  "reproduction": {
    "prompt": {
      "ja": "スティッキー — position: sticky\n\nスクロールに合わせて各区画の見出しが画面上端に貼り付く演出を作ってください。区画は 4 つで、それぞれ高さを 100vh 以上にします。各区画の先頭の見出しに position: sticky; top: 0 を付け、背景は var(--ground) で塗って下の境界線を 1px 引きます。区画の下端に達すると、その見出しは区画の底に押されて画面の上へ消えます。動きを減らす設定では sticky を解除して、4 つの見出しを通常の流れで並べてください。CSS の position: sticky だけで実装し、JavaScript とライブラリは使わないでください。\n\n外すと崩れる点:\n- 見出しは自分の区画の中でだけ貼り付き、区画を越えて残らない\n- 見出しの背景は不透明にし、下の本文が透けないようにする\n- 動きを減らす設定では sticky を解除し、見出しを通常の流れで並べる\n\n動く実物（1 ファイルで完結する HTML）: https://design-vault.pages.dev/designs/motion-sticky/demo.html",
      "en": "Sticky — position: sticky\n\nBuild a section list where each section's heading sticks to the top of the viewport as you scroll. Use four sections, each at least 100vh tall, and give each heading position: sticky; top: 0 with a var(--ground) background and a 1px bottom rule. When a section reaches its end, its bottom edge pushes the heading off the top of the screen. Under prefers-reduced-motion, turn sticky off and show the four headings in normal flow. Implement it with CSS position: sticky alone, with no JavaScript and no library.\n\nDo not drop:\n- Each heading sticks only within its own section, never across sections\n- Headings have an opaque ground background so the content below does not show through\n- Under prefers-reduced-motion, turn sticky off and keep all headings in normal flow\n\nA working example (one self-contained HTML file): https://design-vault.pages.dev/designs/motion-sticky/demo.html"
    },
    "code": {
      "url": "https://design-vault.pages.dev/designs/motion-sticky/demo.html",
      "html": "<!doctype html>\n<html lang=\"ja\">\n<head>\n<meta charset=\"utf-8\">\n<meta name=\"viewport\" content=\"width=device-width, initial-scale=1\">\n<title>17 スティッキー — position: sticky</title>\n<style>\n/* dv-motion-base:start */\n:root {\n  --ground: #FFFFFF;\n  --surface: #F3F5F8;\n  --ink: #14181F;\n  --muted: #5A6472;\n  --accent: #1F5FA8;\n  --rule: #D8DDE4;\n  --accent-soft: color-mix(in srgb, var(--accent) 12%, var(--ground));\n  --accent-mid: color-mix(in srgb, var(--accent) 45%, var(--ground));\n  --shade: color-mix(in srgb, var(--ink) 14%, transparent);\n\n  --font: \"Zen Kaku Gothic New\", \"Hiragino Sans\", \"Noto Sans JP\", \"Yu Gothic\", system-ui, sans-serif;\n  --mono: ui-monospace, \"SF Mono\", Menlo, Consolas, monospace;\n\n  --t-label: 13px;\n  --t-body: 16px;\n  --t-lead: 20px;\n  --t-h2: 32px;\n  --t-h1: clamp(40px, 7vw, 72px);\n\n  --s1: 4px;\n  --s2: 8px;\n  --s3: 16px;\n  --s4: 24px;\n  --s5: 40px;\n  --s6: 64px;\n  --s7: 104px;\n\n  --radius: 12px;\n  --ease: cubic-bezier(.2, .7, .2, 1);\n  --dur: .7s;\n  --measure: 1080px;\n}\n*, *::before, *::after { box-sizing: border-box; }\nhtml { -webkit-text-size-adjust: 100%; }\nbody {\n  margin: 0;\n  background: var(--ground);\n  color: var(--ink);\n  font-family: var(--font);\n  font-size: var(--t-body);\n  line-height: 1.7;\n  font-feature-settings: \"palt\";\n  overflow-x: hidden;\n}\nh1, h2, h3, p, ul, ol, figure { margin: 0; padding: 0; }\nul, ol { list-style: none; }\n.dv-wrap { width: min(100% - 2 * var(--s4), var(--measure)); margin-inline: auto; }\n.dv-label {\n  min-height: 72vh;\n  display: grid;\n  align-content: center;\n  gap: var(--s3);\n  padding-block: var(--s6);\n  border-bottom: 1px solid var(--rule);\n}\n.dv-num { font-family: var(--mono); font-size: var(--t-lead); font-weight: 700; color: var(--accent); letter-spacing: .04em; }\n.dv-name { font-size: var(--t-h1); font-weight: 700; line-height: 1.15; letter-spacing: .01em; }\n.dv-ai { font-family: var(--mono); font-size: var(--t-lead); color: var(--muted); }\n.dv-desc { font-size: var(--t-lead); color: var(--ink); }\n.dv-hint { font-size: var(--t-label); color: var(--muted); letter-spacing: .12em; margin-top: var(--s4); }\n.dv-stage { padding-block: var(--s7); }\n.dv-h2 { font-size: var(--t-h2); font-weight: 700; line-height: 1.3; }\n.dv-lead { font-size: var(--t-lead); color: var(--muted); }\n.dv-eyebrow { font-family: var(--mono); font-size: var(--t-label); color: var(--accent); letter-spacing: .12em; text-transform: uppercase; }\n.dv-card { background: var(--surface); border: 1px solid var(--rule); border-radius: var(--radius); padding: var(--s4); }\n.dv-ph {\n  border-radius: var(--radius);\n  background: linear-gradient(135deg, var(--accent-soft), var(--accent-mid) 60%, var(--accent));\n  aspect-ratio: 16 / 9;\n}\n.dv-ph--alt { background: linear-gradient(200deg, var(--surface), var(--accent-soft) 55%, var(--accent-mid)); }\n.dv-ph--ink { background: linear-gradient(160deg, var(--ink), color-mix(in srgb, var(--ink) 55%, var(--accent))); }\n.dv-end {\n  min-height: 60vh;\n  display: grid;\n  place-items: center;\n  border-top: 1px solid var(--rule);\n  color: var(--muted);\n  font-family: var(--mono);\n  font-size: var(--t-label);\n  letter-spacing: .12em;\n}\n/* dv-motion-base:end */\n\n/* ---- この演出だけの CSS。色は var(--…) か color-mix() のみ ---- */\n.stk-sec { min-height: 100vh; }\n.stk-head {\n  position: sticky;\n  top: 0;\n  z-index: 1;\n  background: var(--ground);\n  border-bottom: 1px solid var(--rule);\n  padding-block: var(--s3);\n}\n.stk-body { display: grid; gap: var(--s4); padding-block: var(--s5); }\n\n@media (prefers-reduced-motion: reduce) {\n  .stk-head { position: static; }\n}\n</style>\n</head>\n<body data-motion-number=\"17\">\n<header class=\"dv-label\">\n  <div class=\"dv-wrap\">\n    <p class=\"dv-num\">17</p>\n    <h1 class=\"dv-name\">スティッキー</h1>\n    <p class=\"dv-ai\">position: sticky</p>\n    <p class=\"dv-desc\">見出しが上に貼り付く</p>\n    <p class=\"dv-hint\">SCROLL ↓</p>\n  </div>\n</header>\n\n<main class=\"dv-stage\">\n  <div class=\"dv-wrap\">\n    <section class=\"stk-sec\">\n      <header class=\"stk-head\">\n        <p class=\"dv-eyebrow\">Section 01 / 04</p>\n        <h2 class=\"dv-h2\">見出しが入ります</h2>\n      </header>\n      <div class=\"stk-body\">\n        <p class=\"dv-lead\">本文のダミーです。見出しは自分の区画の中でだけ貼り付きます。</p>\n        <div class=\"dv-ph\"></div>\n      </div>\n    </section>\n    <section class=\"stk-sec\">\n      <header class=\"stk-head\">\n        <p class=\"dv-eyebrow\">Section 02 / 04</p>\n        <h2 class=\"dv-h2\">見出しが入ります</h2>\n      </header>\n      <div class=\"stk-body\">\n        <p class=\"dv-lead\">本文のダミーです。次の見出しが来ると、この見出しは押し出されます。</p>\n        <div class=\"dv-ph dv-ph--alt\"></div>\n      </div>\n    </section>\n    <section class=\"stk-sec\">\n      <header class=\"stk-head\">\n        <p class=\"dv-eyebrow\">Section 03 / 04</p>\n        <h2 class=\"dv-h2\">見出しが入ります</h2>\n      </header>\n      <div class=\"stk-body\">\n        <p class=\"dv-lead\">本文のダミーです。区画ごとに見出しが入れ替わります。</p>\n        <div class=\"dv-ph dv-ph--ink\"></div>\n      </div>\n    </section>\n    <section class=\"stk-sec\">\n      <header class=\"stk-head\">\n        <p class=\"dv-eyebrow\">Section 04 / 04</p>\n        <h2 class=\"dv-h2\">見出しが入ります</h2>\n      </header>\n      <div class=\"stk-body\">\n        <p class=\"dv-lead\">本文のダミーです。最後の区画の見出しは、ページの終わりまで残ります。</p>\n        <div class=\"dv-ph\"></div>\n      </div>\n    </section>\n  </div>\n</main>\n\n<footer class=\"dv-end\">END — 17 スティッキー</footer>\n\n<script>\n/* dv-motion-helpers:start */\nconst dvReduce = matchMedia('(prefers-reduced-motion: reduce)').matches;\ndocument.documentElement.classList.add('js');\n\n/**\n * 画面に入った要素へ .is-in を付ける。\n * data-reveal=\"repeat\" の要素は画面を出たら外す（何度でも再生）。\n */\nfunction dvReveal(selector = '[data-reveal]', { threshold = 0.2, rootMargin = '0px 0px -8% 0px' } = {}) {\n  const els = [...document.querySelectorAll(selector)];\n  if (dvReduce || !('IntersectionObserver' in window)) {\n    els.forEach((el) => el.classList.add('is-in'));\n    return;\n  }\n  const io = new IntersectionObserver((entries) => {\n    for (const e of entries) {\n      if (e.isIntersecting) {\n        e.target.classList.add('is-in');\n        if (e.target.dataset.reveal !== 'repeat') io.unobserve(e.target);\n      } else if (e.target.dataset.reveal === 'repeat') {\n        e.target.classList.remove('is-in');\n      }\n    }\n  }, { threshold, rootMargin });\n  els.forEach((el) => io.observe(el));\n}\n\n/**\n * スクロール量を 0〜1 にして、各 [data-progress] 要素の CSS 変数 --p に書く。\n *   data-progress=\"through\" : 要素の上端が画面の下端に来たとき 0、下端が画面の上端を抜けたとき 1\n *   data-progress=\"pin\"     : 要素の上端が画面の上端に来たとき 0、下端が画面の下端に来たとき 1\n *                             （中に position: sticky の箱を持つ、背の高い区画用）\n *   data-progress=\"page\"    : ページ全体のスクロール量\n * onUpdate(el, p) を渡すと、値が変わるたびに呼ばれる。\n */\nfunction dvProgress(onUpdate) {\n  const els = [...document.querySelectorAll('[data-progress]')];\n  const clamp = (n) => Math.min(1, Math.max(0, n));\n  let queued = false;\n  const measure = () => {\n    queued = false;\n    const vh = window.innerHeight;\n    for (const el of els) {\n      const r = el.getBoundingClientRect();\n      let p;\n      if (el.dataset.progress === 'pin') p = r.height > vh ? -r.top / (r.height - vh) : 0;\n      else if (el.dataset.progress === 'page') {\n        const max = document.documentElement.scrollHeight - vh;\n        p = max > 0 ? window.scrollY / max : 0;\n      } else p = (vh - r.top) / (vh + r.height);\n      p = clamp(p);\n      el.style.setProperty('--p', p.toFixed(4));\n      if (onUpdate) onUpdate(el, p);\n    }\n  };\n  const request = () => {\n    if (!queued) { queued = true; requestAnimationFrame(measure); }\n  };\n  addEventListener('scroll', request, { passive: true });\n  addEventListener('resize', request);\n  measure();\n}\n/* dv-motion-helpers:end */\n\n/* ---- この演出だけの JS ---- */\n\n</script>\n</body>\n</html>\n"
    }
  },
  "license": "Original",
  "catalogVersion": 1,
  "designSchemaVersion": 2,
  "capabilities": [
    "live-preview",
    "copy-prompt",
    "get-code"
  ],
  "reusePolicy": "construction-reuse",
  "urls": {
    "ja": "https://design-vault.pages.dev/designs/motion-sticky",
    "en": "https://design-vault.pages.dev/en/designs/motion-sticky",
    "json": "https://design-vault.pages.dev/ai/assets/motion-sticky.json",
    "designJson": null
  }
}