A still — with scripts on, it runs right here The demo itself — scroll inside the frame
A still — with scripts on, it runs right here The demo itself — scroll inside the frame
Copy and paste, or save a file and hand it over. For a machine with no network, one “Everything” file is enough.
Everything in this panel, including the contents behind each URL, in one Markdown file — Large, so it goes as a file (copy is for 32 KB and under)
Velocity skew — Scroll-velocity skew Tilt groups of headings according to scroll speed. Measure the scroll amount per animation frame with requestAnimationFrame, multiply the velocity v by 0.02 and apply `skewY(clamp(-6deg, v * 0.02, 6deg))`. Normalise v to a 60 Hz frame so that the tilt does not change with screen refresh rate. When scrolling stops, multiply v by 0.9 each frame so the tilt returns to 0 within a fraction of a second. Tilt five sections, each 80vh tall, containing headings and body text. Write only `transform`, through a CSS variable `--skew`; do not use a library. Do not drop: - The tilt is capped at ±6 degrees, however fast the scroll - When scrolling stops the tilt decays back to 0 and never stays tilted at rest - With reduced motion, nothing tilts and no measuring loop starts A working example (one self-contained HTML file): https://design-vault.pages.dev/designs/motion-velocity-skew/demo.html
/designs/motion-velocity-skew/demo.html — One self-contained HTML file. CSS and plain JavaScript only; it fetches nothing.
<!doctype html>
<html lang="ja">
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1">
<title>40 ベロシティスキュー — Scroll-velocity skew</title>
<style>
/* dv-motion-base:start */
:root {
--ground: #FFFFFF;
--surface: #F3F5F8;
--ink: #14181F;
--muted: #5A6472;
--accent: #1F5FA8;
--rule: #D8DDE4;
--accent-soft: color-mix(in srgb, var(--accent) 12%, var(--ground));
--accent-mid: color-mix(in srgb, var(--accent) 45%, var(--ground));
--shade: color-mix(in srgb, var(--ink) 14%, transparent);
--font: "Zen Kaku Gothic New", "Hiragino Sans", "Noto Sans JP", "Yu Gothic", system-ui, sans-serif;
--mono: ui-monospace, "SF Mono", Menlo, Consolas, monospace;
--t-label: 13px;
--t-body: 16px;
--t-lead: 20px;
--t-h2: 32px;
--t-h1: clamp(40px, 7vw, 72px);
--s1: 4px;
--s2: 8px;
--s3: 16px;
--s4: 24px;
--s5: 40px;
--s6: 64px;
--s7: 104px;
--radius: 12px;
--ease: cubic-bezier(.2, .7, .2, 1);
--dur: .7s;
--measure: 1080px;
}
*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
margin: 0;
background: var(--ground);
color: var(--ink);
font-family: var(--font);
font-size: var(--t-body);
line-height: 1.7;
font-feature-settings: "palt";
overflow-x: hidden;
}
h1, h2, h3, p, ul, ol, figure { margin: 0; padding: 0; }
ul, ol { list-style: none; }
.dv-wrap { width: min(100% - 2 * var(--s4), var(--measure)); margin-inline: auto; }
.dv-label {
min-height: 72vh;
display: grid;
align-content: center;
gap: var(--s3);
padding-block: var(--s6);
border-bottom: 1px solid var(--rule);
}
.dv-num { font-family: var(--mono); font-size: var(--t-lead); font-weight: 700; color: var(--accent); letter-spacing: .04em; }
.dv-name { font-size: var(--t-h1); font-weight: 700; line-height: 1.15; letter-spacing: .01em; }
.dv-ai { font-family: var(--mono); font-size: var(--t-lead); color: var(--muted); }
.dv-desc { font-size: var(--t-lead); color: var(--ink); }
.dv-hint { font-size: var(--t-label); color: var(--muted); letter-spacing: .12em; margin-top: var(--s4); }
.dv-stage { padding-block: var(--s7); }
.dv-h2 { font-size: var(--t-h2); font-weight: 700; line-height: 1.3; }
.dv-lead { font-size: var(--t-lead); color: var(--muted); }
.dv-eyebrow { font-family: var(--mono); font-size: var(--t-label); color: var(--accent); letter-spacing: .12em; text-transform: uppercase; }
.dv-card { background: var(--surface); border: 1px solid var(--rule); border-radius: var(--radius); padding: var(--s4); }
.dv-ph {
border-radius: var(--radius);
background: linear-gradient(135deg, var(--accent-soft), var(--accent-mid) 60%, var(--accent));
aspect-ratio: 16 / 9;
}
.dv-ph--alt { background: linear-gradient(200deg, var(--surface), var(--accent-soft) 55%, var(--accent-mid)); }
.dv-ph--ink { background: linear-gradient(160deg, var(--ink), color-mix(in srgb, var(--ink) 55%, var(--accent))); }
.dv-end {
min-height: 60vh;
display: grid;
place-items: center;
border-top: 1px solid var(--rule);
color: var(--muted);
font-family: var(--mono);
font-size: var(--t-label);
letter-spacing: .12em;
}
/* dv-motion-base:end */
/* ---- この演出だけの CSS。色は var(--…) か color-mix() のみ ---- */
.stack { display: grid; gap: var(--s7); }
.vs-block { min-height: 80vh; display: grid; align-content: center; }
.vs-group { transform: skewY(var(--skew, 0deg)); transform-origin: 0 50%; will-change: transform; }
.vs-tag { font-family: var(--mono); font-size: var(--t-label); color: var(--accent); letter-spacing: .12em; }
@media (prefers-reduced-motion: reduce) {
.vs-group { transform: none; }
}
</style>
</head>
<body data-motion-number="40">
<header class="dv-label">
<div class="dv-wrap">
<p class="dv-num">40</p>
<h1 class="dv-name">ベロシティスキュー</h1>
<p class="dv-ai">Scroll-velocity skew</p>
<p class="dv-desc">速くスクロールすると傾く</p>
<p class="dv-hint">SCROLL ↓</p>
</div>
</header>
<main class="dv-stage">
<div class="dv-wrap stack">
<section class="vs-block">
<div class="vs-group">
<p class="vs-tag">Section 1</p>
<h2 class="dv-h2">見出しが入ります</h2>
<p class="dv-lead">本文のダミーです。速くスクロールすると、見出しの群が傾きます。</p>
</div>
</section>
<section class="vs-block">
<div class="vs-group">
<p class="vs-tag">Section 2</p>
<h2 class="dv-h2">見出しが入ります</h2>
<p class="dv-lead">本文のダミーです。止めると、傾きは減衰して 0 に戻ります。</p>
</div>
</section>
<section class="vs-block">
<div class="vs-group">
<p class="vs-tag">Section 3</p>
<h2 class="dv-h2">見出しが入ります</h2>
<div class="dv-ph"></div>
</div>
</section>
<section class="vs-block">
<div class="vs-group">
<p class="vs-tag">Section 4</p>
<h2 class="dv-h2">見出しが入ります</h2>
<p class="dv-lead">本文のダミーです。動きを減らす設定では、傾かずに静止したままです。</p>
</div>
</section>
<section class="vs-block">
<div class="vs-group">
<p class="vs-tag">Section 5</p>
<h2 class="dv-h2">見出しが入ります</h2>
<div class="dv-ph dv-ph--alt"></div>
</div>
</section>
</div>
</main>
<footer class="dv-end">END — 40 ベロシティスキュー</footer>
<script>
/* dv-motion-helpers:start */
const dvReduce = matchMedia('(prefers-reduced-motion: reduce)').matches;
document.documentElement.classList.add('js');
/**
* 画面に入った要素へ .is-in を付ける。
* data-reveal="repeat" の要素は画面を出たら外す（何度でも再生）。
*/
function dvReveal(selector = '[data-reveal]', { threshold = 0.2, rootMargin = '0px 0px -8% 0px' } = {}) {
const els = [...document.querySelectorAll(selector)];
if (dvReduce || !('IntersectionObserver' in window)) {
els.forEach((el) => el.classList.add('is-in'));
return;
}
const io = new IntersectionObserver((entries) => {
for (const e of entries) {
if (e.isIntersecting) {
e.target.classList.add('is-in');
if (e.target.dataset.reveal !== 'repeat') io.unobserve(e.target);
} else if (e.target.dataset.reveal === 'repeat') {
e.target.classList.remove('is-in');
}
}
}, { threshold, rootMargin });
els.forEach((el) => io.observe(el));
}
/**
* 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。
* 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
* 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
* （中に position: sticky の箱を持つ、背の高い区画用）
* data-progress="page" : ページ全体のスクロール量
* onUpdate(el, p) を渡すと、値が変わるたびに呼ばれる。
*/
function dvProgress(onUpdate) {
const els = [...document.querySelectorAll('[data-progress]')];
const clamp = (n) => Math.min(1, Math.max(0, n));
let queued = false;
const measure = () => {
queued = false;
const vh = window.innerHeight;
for (const el of els) {
const r = el.getBoundingClientRect();
let p;
if (el.dataset.progress === 'pin') p = r.height > vh ? -r.top / (r.height - vh) : 0;
else if (el.dataset.progress === 'page') {
const max = document.documentElement.scrollHeight - vh;
p = max > 0 ? window.scrollY / max : 0;
} else p = (vh - r.top) / (vh + r.height);
p = clamp(p);
el.style.setProperty('--p', p.toFixed(4));
if (onUpdate) onUpdate(el, p);
}
};
const request = () => {
if (!queued) { queued = true; requestAnimationFrame(measure); }
};
addEventListener('scroll', request, { passive: true });
addEventListener('resize', request);
measure();
}
/* dv-motion-helpers:end */
/* ---- この演出だけの JS ---- */
// スクロール速度（60Hz の 1 フレームあたりの px）を測り、減衰させながら
// 見出し群の --skew に写す。止まれば 0 に戻る。動きを減らす設定では動かさない。
if (!dvReduce) {
const groups = [...document.querySelectorAll('.vs-group')];
const clamp = (n, lo, hi) => Math.min(hi, Math.max(lo, n));
const decay = 0.9;
let lastY = scrollY;
let lastT = 0;
let v = 0;
let running = false;
const frame = (now) => {
const dt = lastT ? Math.min(now - lastT, 100) : 16.67;
lastT = now;
const dy = scrollY - lastY;
lastY = scrollY;
v = dy !== 0 ? (dy / dt) * 16.67 : v * Math.pow(decay, dt / 16.67);
const skew = clamp(v * 0.02, -6, 6);
for (const el of groups) el.style.setProperty('--skew', skew.toFixed(3) + 'deg');
if (Math.abs(v) > 0.01) {
requestAnimationFrame(frame);
} else {
v = 0;
running = false;
lastT = 0;
for (const el of groups) el.style.setProperty('--skew', '0deg');
}
};
// lastY はここでは更新しない。scroll イベントは同じフレームの rAF の直前に来るので、
// ここで scrollY を写すと frame の差分が 0 になり、速さが一度も測れない。
const start = () => {
if (running) return;
running = true;
requestAnimationFrame(frame);
};
addEventListener('scroll', start, { passive: true });
}
</script>
</body>
</html>