{
  "id": "alternate-column-scroll",
  "kind": "element",
  "title": "Alternate column scroll",
  "summary": "A three-column image grid where the outer columns slide up and the middle column slides down as you scroll inside it, smoothed with a lerp and a touch of skew.",
  "url": "https://enrichr.dev/elements/alternate-column-scroll.html",
  "section": "gallery",
  "techniques": [
    "scroll-driven",
    "parallax"
  ],
  "stack": [
    "Vanilla JS",
    "CSS"
  ],
  "frameworks": [
    "React",
    "Next.js",
    "Vanilla"
  ],
  "mood": [
    "kinetic",
    "modern",
    "editorial"
  ],
  "intents": [
    "alternating column scroll grid",
    "columns scroll in opposite directions",
    "scroll driven image grid animation",
    "three column parallax gallery",
    "opposite direction scrolling columns"
  ],
  "status": "tested",
  "params": [
    {
      "key": "accent",
      "label": "Accent colour",
      "type": "color",
      "value": "#e6ff55"
    },
    {
      "key": "ease",
      "label": "Smoothing (higher is snappier)",
      "type": "range",
      "min": 0.04,
      "max": 0.4,
      "step": 0.01,
      "value": 0.1
    },
    {
      "key": "skew",
      "label": "Velocity skew",
      "type": "range",
      "min": 0,
      "max": 1.5,
      "step": 0.05,
      "value": 1
    },
    {
      "key": "gap",
      "label": "Gap (px)",
      "type": "range",
      "min": 2,
      "max": 32,
      "step": 1,
      "value": 12
    },
    {
      "key": "tiles",
      "label": "Tiles per column",
      "type": "range",
      "min": 3,
      "max": 6,
      "step": 1,
      "value": 4
    }
  ],
  "license": "Free to use in personal and client projects during the preview. Final licence terms will be published here before any paid tier starts; ask before reselling the code as a collection.",
  "contract": "function mount(root, opts) -> { update(partialOpts), destroy() }; root must contain the element markup",
  "exports": {
    "claude": "Add the \"Alternate column scroll\" element to this project.\n\nThis is the \"Alternate column scroll\" element from the Enrichr Library: A three-column image grid where the outer columns slide up and the middle column slides down as you scroll inside it, smoothed with a lerp and a touch of skew.\nPage: https://enrichr.dev/elements/alternate-column-scroll.html\nMachine-readable spec: https://enrichr.dev/elements/alternate-column-scroll.json\n\nElement contract (vanilla JavaScript, no dependencies):\n- The JavaScript defines a function mount(root, opts).\n- root is an empty container element. Set root.innerHTML to the markup first, then call mount(root, opts).\n- It returns an object with update(partialOpts) and destroy(). Call destroy() when the element is removed. Some elements also return replay().\n- The CSS classes all start with \"ef-\" so they will not collide with your styles.\n\nSteps:\n1. Look at the project first to see its framework and where components, styles and static files live. Follow its conventions.\n2. Fetch https://enrichr.dev/elements/alternate-column-scroll.json if you can read URLs (fields: source.markup, source.css, source.js, params); otherwise use the source at the end of this message.\n3. Add the files, mount it where I tell you (default: the top of the home page), and pass the settings below as the opts.\n4. Keep the behaviour of the source unchanged. Do not add dependencies. Respect prefers-reduced-motion. Keep text as real HTML.\n5. Run the dev server and check it. with reduced motion on, nothing moves; it works at 375px wide and with touch only; there are no console errors; scrolling stays smooth; destroy() is called when it unmounts.\n\nSettings:\n{{SETTINGS}}\n\nSource:\n{{CODE}}",
    "chatgpt": "I want the \"Alternate column scroll\" element on my website. Below is its complete source. Please:\n1. Build one self-contained index.html that I can open locally to see it working (put the CSS in a <style> tag and the JavaScript in a <script> tag, with the markup in the body).\n2. Then explain, step by step, which parts go where in my own site, and how to mount it. My stack is: [tell me yours, or say \"plain HTML\"].\n3. Keep the behaviour of the source unchanged. Do not add dependencies. Respect prefers-reduced-motion. Keep text as real HTML.\n\nThis is the \"Alternate column scroll\" element from the Enrichr Library: A three-column image grid where the outer columns slide up and the middle column slides down as you scroll inside it, smoothed with a lerp and a touch of skew.\nPage: https://enrichr.dev/elements/alternate-column-scroll.html\nMachine-readable spec: https://enrichr.dev/elements/alternate-column-scroll.json\n\nElement contract (vanilla JavaScript, no dependencies):\n- The JavaScript defines a function mount(root, opts).\n- root is an empty container element. Set root.innerHTML to the markup first, then call mount(root, opts).\n- It returns an object with update(partialOpts) and destroy(). Call destroy() when the element is removed. Some elements also return replay().\n- The CSS classes all start with \"ef-\" so they will not collide with your styles.\n\nSettings:\n{{SETTINGS}}\n\nSource:\n{{CODE}}\n\nVerify: with reduced motion on, nothing moves; it works at 375px wide and with touch only; there are no console errors; scrolling stays smooth; destroy() is called when it unmounts.",
    "cursor": "Add the \"Alternate column scroll\" element to this codebase.\n\nThis is the \"Alternate column scroll\" element from the Enrichr Library: A three-column image grid where the outer columns slide up and the middle column slides down as you scroll inside it, smoothed with a lerp and a touch of skew.\nPage: https://enrichr.dev/elements/alternate-column-scroll.html\nMachine-readable spec: https://enrichr.dev/elements/alternate-column-scroll.json\n\nElement contract (vanilla JavaScript, no dependencies):\n- The JavaScript defines a function mount(root, opts).\n- root is an empty container element. Set root.innerHTML to the markup first, then call mount(root, opts).\n- It returns an object with update(partialOpts) and destroy(). Call destroy() when the element is removed. Some elements also return replay().\n- The CSS classes all start with \"ef-\" so they will not collide with your styles.\n\nUse Composer / agent mode. First search the repo for how components, styles and scripts are organised, then add the files in the matching places, mount it on the page I name, and run the app to confirm it works. Keep the behaviour of the source unchanged. Do not add dependencies. Respect prefers-reduced-motion. Keep text as real HTML.\n\nSettings:\n{{SETTINGS}}\n\nSource:\n{{CODE}}\n\nVerify: with reduced motion on, nothing moves; it works at 375px wide and with touch only; there are no console errors; scrolling stays smooth; destroy() is called when it unmounts.\n\nOptional: save this as .cursor/rules/enrichr-alternate-column-scroll.mdc so the rule stays with the project:\n---\ndescription: How to use the Enrichr Alternate column scroll element\nalwaysApply: false\n---\nmount(root, opts) expects the element markup inside root and returns { update, destroy }. Always call destroy() on unmount and never edit the ef- class names.",
    "v0": "Create a Next.js (App Router) client component for the \"Alternate column scroll\" element. Tailwind is available but this component needs no utility classes.\n\nThis is the \"Alternate column scroll\" element from the Enrichr Library: A three-column image grid where the outer columns slide up and the middle column slides down as you scroll inside it, smoothed with a lerp and a touch of skew.\nPage: https://enrichr.dev/elements/alternate-column-scroll.html\nMachine-readable spec: https://enrichr.dev/elements/alternate-column-scroll.json\n\nElement contract (vanilla JavaScript, no dependencies):\n- The JavaScript defines a function mount(root, opts).\n- root is an empty container element. Set root.innerHTML to the markup first, then call mount(root, opts).\n- It returns an object with update(partialOpts) and destroy(). Call destroy() when the element is removed. Some elements also return replay().\n- The CSS classes all start with \"ef-\" so they will not collide with your styles.\n\nFiles to create:\n- alternate-column-scroll.js : the JavaScript below, with one line appended at the end: export { mount };  (and the markup exported as: export const markup = \"<the markup string>\";). If the project uses TypeScript and does not allow JS imports, put // @ts-nocheck on the first line.\n- the CSS below goes in your global stylesheet (or a plain .css file imported once at the app root). The class names are global and start with ef-.\n\nUse this component as the wrapper (adjust the import paths):\n```tsx\n\"use client\";\nimport { useEffect, useRef } from \"react\";\nimport { markup, mount } from \"./alternate-column-scroll\"; // markup is the HTML string; mount is the JavaScript's mount function\n\nexport default function AlternateColumnScroll(props: Record<string, unknown>) {\n  const ref = useRef<HTMLDivElement>(null);\n  const fx = useRef<{ update: (o: object) => void; destroy: () => void } | null>(null);\n  useEffect(() => {\n    const root = ref.current;\n    if (!root) return;\n    root.innerHTML = markup;\n    fx.current = mount(root, props);\n    return () => { fx.current?.destroy(); fx.current = null; root.innerHTML = \"\"; };\n  }, []);\n  useEffect(() => { fx.current?.update(props); }, [JSON.stringify(props)]);\n  return <div ref={ref} />;\n}\n```\n\nRender it on the home page so I can see it. Keep the behaviour of the source unchanged. Do not add dependencies. Respect prefers-reduced-motion. Keep text as real HTML.\n\nSettings:\n{{SETTINGS}}\n\nSource:\n{{CODE}}",
    "lovable": "Add the \"Alternate column scroll\" element to this React + Vite + TypeScript + Tailwind project. Do not install any packages.\n\nThis is the \"Alternate column scroll\" element from the Enrichr Library: A three-column image grid where the outer columns slide up and the middle column slides down as you scroll inside it, smoothed with a lerp and a touch of skew.\nPage: https://enrichr.dev/elements/alternate-column-scroll.html\nMachine-readable spec: https://enrichr.dev/elements/alternate-column-scroll.json\n\nElement contract (vanilla JavaScript, no dependencies):\n- The JavaScript defines a function mount(root, opts).\n- root is an empty container element. Set root.innerHTML to the markup first, then call mount(root, opts).\n- It returns an object with update(partialOpts) and destroy(). Call destroy() when the element is removed. Some elements also return replay().\n- The CSS classes all start with \"ef-\" so they will not collide with your styles.\n\nFiles to create:\n- alternate-column-scroll.js : the JavaScript below, with one line appended at the end: export { mount };  (and the markup exported as: export const markup = \"<the markup string>\";). If the project uses TypeScript and does not allow JS imports, put // @ts-nocheck on the first line.\n- the CSS below goes in your global stylesheet (or a plain .css file imported once at the app root). The class names are global and start with ef-.\n\nWrapper component (src/components/AlternateColumnScroll.tsx):\n```tsx\n\"use client\";\nimport { useEffect, useRef } from \"react\";\nimport { markup, mount } from \"./alternate-column-scroll\"; // markup is the HTML string; mount is the JavaScript's mount function\n\nexport default function AlternateColumnScroll(props: Record<string, unknown>) {\n  const ref = useRef<HTMLDivElement>(null);\n  const fx = useRef<{ update: (o: object) => void; destroy: () => void } | null>(null);\n  useEffect(() => {\n    const root = ref.current;\n    if (!root) return;\n    root.innerHTML = markup;\n    fx.current = mount(root, props);\n    return () => { fx.current?.destroy(); fx.current = null; root.innerHTML = \"\"; };\n  }, []);\n  useEffect(() => { fx.current?.update(props); }, [JSON.stringify(props)]);\n  return <div ref={ref} />;\n}\n```\n\nRemove the \"use client\" line if it is not needed. Show it on the home page. Keep the behaviour of the source unchanged. Do not add dependencies. Respect prefers-reduced-motion. Keep text as real HTML.\n\nSettings:\n{{SETTINGS}}\n\nSource:\n{{CODE}}",
    "bolt": "Create a small Vite project (vanilla JavaScript, no framework unless I already have one) that shows the \"Alternate column scroll\" element.\n\nThis is the \"Alternate column scroll\" element from the Enrichr Library: A three-column image grid where the outer columns slide up and the middle column slides down as you scroll inside it, smoothed with a lerp and a touch of skew.\nPage: https://enrichr.dev/elements/alternate-column-scroll.html\nMachine-readable spec: https://enrichr.dev/elements/alternate-column-scroll.json\n\nElement contract (vanilla JavaScript, no dependencies):\n- The JavaScript defines a function mount(root, opts).\n- root is an empty container element. Set root.innerHTML to the markup first, then call mount(root, opts).\n- It returns an object with update(partialOpts) and destroy(). Call destroy() when the element is removed. Some elements also return replay().\n- The CSS classes all start with \"ef-\" so they will not collide with your styles.\n\nFiles: index.html (a container element, then a script tag), style.css (the CSS below), alternate-column-scroll.js (the JavaScript below) and main.js that sets the container's innerHTML to the markup and calls mount(container, opts) with the settings below. Keep the behaviour of the source unchanged. Do not add dependencies. Respect prefers-reduced-motion. Keep text as real HTML.\n\nSettings:\n{{SETTINGS}}\n\nSource:\n{{CODE}}\n\nVerify: with reduced motion on, nothing moves; it works at 375px wide and with touch only; there are no console errors; scrolling stays smooth; destroy() is called when it unmounts.",
    "replit": "Create a new HTML, CSS and JavaScript Repl that shows the \"Alternate column scroll\" element. No packages, no server code.\n\nThis is the \"Alternate column scroll\" element from the Enrichr Library: A three-column image grid where the outer columns slide up and the middle column slides down as you scroll inside it, smoothed with a lerp and a touch of skew.\nPage: https://enrichr.dev/elements/alternate-column-scroll.html\nMachine-readable spec: https://enrichr.dev/elements/alternate-column-scroll.json\n\nElement contract (vanilla JavaScript, no dependencies):\n- The JavaScript defines a function mount(root, opts).\n- root is an empty container element. Set root.innerHTML to the markup first, then call mount(root, opts).\n- It returns an object with update(partialOpts) and destroy(). Call destroy() when the element is removed. Some elements also return replay().\n- The CSS classes all start with \"ef-\" so they will not collide with your styles.\n\nFiles: index.html (a container element, link style.css, load alternate-column-scroll.js and then main.js), style.css (the CSS below), alternate-column-scroll.js (the JavaScript below), main.js (sets the container's innerHTML to the markup, then calls mount(container, opts) with the settings below). Press Run to preview. Keep the behaviour of the source unchanged. Do not add dependencies. Respect prefers-reduced-motion. Keep text as real HTML.\n\nSettings:\n{{SETTINGS}}\n\nSource:\n{{CODE}}",
    "figma": "Designer handoff notes for the \"Alternate column scroll\" element (Enrichr Library). Figma cannot run this JavaScript inside a design file, so use it as a motion reference and hand the code to a developer.\n\nThis is the \"Alternate column scroll\" element from the Enrichr Library: A three-column image grid where the outer columns slide up and the middle column slides down as you scroll inside it, smoothed with a lerp and a touch of skew.\nPage: https://enrichr.dev/elements/alternate-column-scroll.html\nMachine-readable spec: https://enrichr.dev/elements/alternate-column-scroll.json\n\nWhat it does: The container scrolls natively and holds a sticky stage with three tall columns. A requestAnimationFrame loop eases a current scroll value toward scrollTop, turns it into progress from 0 to 1, and maps that to each column's own travel distance (its height minus the viewport height). Columns one and three move from 0 to minus their travel; column two starts pulled up by its travel and moves back down. Because every column is driven by the same progress they stay in sync while heading in opposite directions. The speed of the easing adds a small skew that flips sign on alternate columns. The loop sleeps once everything has settled.\nAccessibility: The scroller is a focusable region with a visible focus ring, so arrow keys, Page Up and Down, Home and End all work, and touch scrolling is native. With prefers-reduced-motion the easing and skew are off and the columns follow the scroll position directly. Tiles carry short text labels over a darkening scrim. If the grid becomes real content, keep it in reading order, since the middle column moves independently.\n\nTunable settings:\n- Accent colour: color, default #e6ff55\n- Smoothing (higher is snappier): range 0.04 to 0.4, step 0.01, default 0.1\n- Velocity skew: range 0 to 1.5, step 0.05, default 1\n- Gap (px): range 2 to 32, step 1, default 12\n- Tiles per column: range 3 to 6, step 1, default 4\n\nCurrent settings:\n{{SETTINGS}}\n\nFor the developer: Element contract (vanilla JavaScript, no dependencies):\n- The JavaScript defines a function mount(root, opts).\n- root is an empty container element. Set root.innerHTML to the markup first, then call mount(root, opts).\n- It returns an object with update(partialOpts) and destroy(). Call destroy() when the element is removed. Some elements also return replay().\n- The CSS classes all start with \"ef-\" so they will not collide with your styles.\n\nIn Figma:\n- Draw the resting state as a frame and the end state as a second frame; link them with Smart Animate to show the motion in a prototype.\n- Put the settings above in the frame's notes or Dev Mode annotations so the developer matches them.\n- Link https://enrichr.dev/elements/alternate-column-scroll.html in the handoff: the live demo and the copy-ready code are there. Developers can paste the prompts for Claude, Cursor or v0 from the Export menu.\nNothing is copied from another designer's file; this is original code from Enrichr.",
    "framer": "Add the \"Alternate column scroll\" element to Framer as a code component. Framer code components are React, so wrap the vanilla code like this. Check it in the Framer editor, as Framer's component API can change.\n\nThis is the \"Alternate column scroll\" element from the Enrichr Library: A three-column image grid where the outer columns slide up and the middle column slides down as you scroll inside it, smoothed with a lerp and a touch of skew.\nPage: https://enrichr.dev/elements/alternate-column-scroll.html\nMachine-readable spec: https://enrichr.dev/elements/alternate-column-scroll.json\n\nElement contract (vanilla JavaScript, no dependencies):\n- The JavaScript defines a function mount(root, opts).\n- root is an empty container element. Set root.innerHTML to the markup first, then call mount(root, opts).\n- It returns an object with update(partialOpts) and destroy(). Call destroy() when the element is removed. Some elements also return replay().\n- The CSS classes all start with \"ef-\" so they will not collide with your styles.\n\n1. In Framer: Assets > Code > New component. Name it AlternateColumnScroll.\n2. Paste the JavaScript below into a separate code file named alternate-column-scroll.js in the same project, with  export { mount };  and  export const markup = \"<the markup string>\";  added. Put the CSS into the component as a <style> tag.\n3. Component:\n```tsx\nimport { addPropertyControls, ControlType } from \"framer\"\nimport { useEffect, useRef } from \"react\";\nimport { markup, mount } from \"./alternate-column-scroll\"; // markup is the HTML string; mount is the JavaScript's mount function\n\nexport default function AlternateColumnScroll(props: any) {\n  const ref = useRef<HTMLDivElement>(null);\n  const fx = useRef<{ update: (o: object) => void; destroy: () => void } | null>(null);\n  useEffect(() => {\n    const root = ref.current;\n    if (!root) return;\n    root.innerHTML = markup;\n    fx.current = mount(root, props);\n    return () => { fx.current?.destroy(); fx.current = null; root.innerHTML = \"\"; };\n  }, []);\n  useEffect(() => { fx.current?.update(props); }, [JSON.stringify(props)]);\n  return <div ref={ref} />;\n}\n\naddPropertyControls(AlternateColumnScroll, {\n  accent: { type: ControlType.Color, title: \"Accent colour\", defaultValue: \"#e6ff55\" },\n  ease: { type: ControlType.Number, title: \"Smoothing\", min: 0.04, max: 0.4, step: 0.01, defaultValue: 0.1 },\n  skew: { type: ControlType.Number, title: \"Velocity skew\", min: 0, max: 1.5, step: 0.05, defaultValue: 1 },\n  gap: { type: ControlType.Number, title: \"Gap\", min: 2, max: 32, step: 1, defaultValue: 12 },\n  tiles: { type: ControlType.Number, title: \"Tiles per column\", min: 3, max: 6, step: 1, defaultValue: 4 },\n})\n```\n4. Keep the behaviour of the source unchanged. Do not add dependencies. Respect prefers-reduced-motion. Keep text as real HTML.\n\nSettings:\n{{SETTINGS}}\n\nSource:\n{{CODE}}",
    "webflow": "Add the \"Alternate column scroll\" element to a Webflow site with an Embed element. Test it on the published or preview site: scripts in embeds may not run inside the Designer canvas.\n\nThis is the \"Alternate column scroll\" element from the Enrichr Library: A three-column image grid where the outer columns slide up and the middle column slides down as you scroll inside it, smoothed with a lerp and a touch of skew.\nPage: https://enrichr.dev/elements/alternate-column-scroll.html\nMachine-readable spec: https://enrichr.dev/elements/alternate-column-scroll.json\n\nElement contract (vanilla JavaScript, no dependencies):\n- The JavaScript defines a function mount(root, opts).\n- root is an empty container element. Set root.innerHTML to the markup first, then call mount(root, opts).\n- It returns an object with update(partialOpts) and destroy(). Call destroy() when the element is removed. Some elements also return replay().\n- The CSS classes all start with \"ef-\" so they will not collide with your styles.\n\n1. Add an Embed element where it should appear. Paste a <style> block with the CSS, one container <div id=\"enrichr-alternate-column-scroll\"></div>, and a <script> block with the JavaScript followed by:\n   mount(document.getElementById(\"enrichr-alternate-column-scroll\"), { ...your settings... });\n   (set the container's innerHTML to the markup first, as in the contract).\n2. Embed elements have a size limit (check Webflow's current number). If the code is longer, host the JS and CSS as files and link them from Custom code in the page settings, then keep only the container and the mount call in the Embed.\n3. Keep the behaviour of the source unchanged. Do not add dependencies. Respect prefers-reduced-motion. Keep text as real HTML.\n\nSettings:\n{{SETTINGS}}\n\nSource:\n{{CODE}}"
  },
  "exportTools": [
    "claude",
    "chatgpt",
    "cursor",
    "v0",
    "lovable",
    "bolt",
    "replit",
    "figma",
    "framer",
    "webflow"
  ],
  "accessibility": "The scroller is a focusable region with a visible focus ring, so arrow keys, Page Up and Down, Home and End all work, and touch scrolling is native. With prefers-reduced-motion the easing and skew are off and the columns follow the scroll position directly. Tiles carry short text labels over a darkening scrim. If the grid becomes real content, keep it in reading order, since the middle column moves independently.",
  "performance": "Each frame writes one transform per column, three in total. Column heights are measured on build and on resize through a ResizeObserver, not in the loop. The scroll range is bounded, so at either end the page can continue to scroll normally instead of being trapped.",
  "dependencies": [],
  "source": {
    "markup": "<div class=\"ef-acs\">\n  <div class=\"ef-acs__wrap\">\n    <div class=\"ef-acs__view\" tabindex=\"0\" role=\"region\" aria-label=\"Image grid, scroll to explore\">\n      <div class=\"ef-acs__space\"><div class=\"ef-acs__stage\"><div class=\"ef-acs__cols\"></div></div></div>\n    </div>\n  </div>\n</div>",
    "css": "/* Enrichr Library · https://enrichr.dev */\n.ef-acs { width: 100%; }\n.ef-acs__wrap { --g: 12px; box-sizing: border-box; width: 100%; padding: 1rem; border-radius: 1rem; font-family: system-ui, -apple-system, \"Segoe UI\", Roboto, sans-serif; }\n.ef-acs__view { position: relative; height: 26rem; max-height: 80vh; overflow-x: hidden; overflow-y: auto; border-radius: 0.8rem; scrollbar-width: none; overscroll-behavior: contain; outline: none; }\n.ef-acs__view::-webkit-scrollbar { display: none; }\n.ef-acs__view:focus-visible { box-shadow: 0 0 0 2px var(--ef-acc, #e6ff55); }\n.ef-acs__space { position: relative; }\n.ef-acs__stage { position: sticky; top: 0; height: 26rem; overflow: hidden; }\n.ef-acs__cols { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: var(--g); align-items: start; }\n.ef-acs__col { display: flex; flex-direction: column; gap: var(--g); will-change: transform; }\n.ef-acs__tile { position: relative; border-radius: 0.7rem; overflow: hidden; color: #fbf8f1; }\n.ef-acs__tile::after { content: \"\"; position: absolute; inset: 0; background: linear-gradient(180deg, transparent 50%, rgba(0, 0, 0, 0.55)); }\n.ef-acs__t { position: absolute; z-index: 1; left: 0.6rem; bottom: 0.5rem; font-size: 0.78rem; font-weight: 800; letter-spacing: 0.02em; text-shadow: 0 2px 8px rgba(0, 0, 0, 0.4); }\n@media (prefers-reduced-motion: reduce) { .ef-acs__col { will-change: auto; } }",
    "js": "// Enrichr Library · https://enrichr.dev\n// Alternate column scroll: a three-column gradient grid inside its own scroll container. Native scrolling sets a target, a rAF loop\n// eases toward it with a lerp, and the progress (0-1) moves the outer columns up while the middle column moves down. Scroll speed adds\n// a small skew. The loop sleeps when settled. Reduced motion: no easing and no skew; columns still track the scroll position.\n// mount(root, { background, accent, ease (0.04-0.4), skew (0-1.5), gap (px), tiles (3-6) })\nfunction mount(root, o) {\n  var reduce = window.matchMedia(\"(prefers-reduced-motion: reduce)\").matches;\n  var wrap = root.querySelector(\".ef-acs__wrap\");\n  var view = root.querySelector(\".ef-acs__view\");\n  var space = root.querySelector(\".ef-acs__space\");\n  var stage = root.querySelector(\".ef-acs__stage\");\n  var colsEl = root.querySelector(\".ef-acs__cols\");\n  var opts = {}, cols = [], ranges = [];\n  var viewH = 0, cur = 0, target = 0, raf = 0, ro = null, offs = [], dead = false;\n  var NAMES = [\"Tidal\", \"Ember\", \"Moss\", \"Dusk\", \"Arch\", \"Grain\", \"Haze\", \"Loop\", \"Drift\", \"Fern\", \"Slate\", \"Pulse\", \"Dune\", \"Mist\", \"Rune\", \"Glow\", \"Echo\", \"Bloom\"];\n  var RATIOS = [[1.3, 0.9, 1.5, 1.1, 1.4, 0.85], [0.95, 1.45, 1.05, 1.35, 0.9, 1.25], [1.5, 1.1, 0.85, 1.4, 1.2, 1.0]];\n\n  // Enrichr puzzle-piece artwork, inline so the code stays portable. piece(i, accent) returns an aria-hidden SVG string, a different piece per card.\n  var PIECES = [[\"1513.7 1453.9 322.3 322.3\", \"M1821 1761.2h-292.3v-111.6c0-8 6.5-14.5 14.5-14.5 4.2 0 8.2 1.9 11 5.1 7.8 8.6 19.7 13.6 32.7 11.9 16.8-2.3 30.1-16 32-32.7 2.5-22.6-15.1-41.6-37.1-41.6-11 0-20.9 4.7-27.7 12.3-2.8 3.1-6.7 4.9-10.9 4.9-8 0-14.5-6.4-14.5-14.4v-111.7h292.3v111.7c0 8-6.4 14.4-14.5 14.4-4.2 0-8.1-1.8-10.9-5-7.9-8.6-19.7-13.6-32.7-11.9-16.8 2.2-30.1 15.9-32 32.7-2.5 22.6 15.1 41.6 37.1 41.6 11 0 20.8-4.8 27.7-12.3 2.8-3.1 6.7-5 10.8-5 8.1 0 14.5 6.5 14.5 14.5z\"],\n    [\"1423.36 860.8 503.07 322.3\", \"M1821 875.8v111.6c0 8 6.5 14.5 14.5 14.5 4.2 0 8.1-1.9 10.9-5 6.8-7.5 16.7-12.3 27.7-12.3 22 0 39.6 19 37.1 41.6-1.9 16.7-15.2 30.5-32 32.7-13 1.7-24.8-3.3-32.7-11.9-2.8-3.2-6.8-5-11-5-8 0-14.5 6.4-14.5 14.4v111.7h-111.6c-8 0-14.5-6.5-14.5-14.5 0-4.2 1.9-8.2 5-11 8.7-7.9 13.7-19.7 12-32.7-2.3-16.8-16-30.1-32.8-32-22.5-2.5-41.5 15.1-41.5 37.1 0 11 4.7 20.9 12.3 27.7 3.1 2.8 4.9 6.7 4.9 10.8v0.1c0 8-6.4 14.5-14.5 14.5h-111.6v-111.7c0-8-6.4-14.4-14.5-14.4-4.1 0-8 1.8-10.8 4.9-6.9 7.6-16.7 12.3-27.7 12.3-22 0-39.6-19-37.1-41.6 1.9-16.7 15.2-30.4 32-32.7 13-1.7 24.8 3.3 32.7 11.9 2.8 3.2 6.7 5.1 10.9 5.1 8.1 0 14.5-6.5 14.5-14.5v-111.6z\"],\n    [\"1513.7 166.86 322.3 503.06\", \"M1528.7 564.5v-111.6c0-8 6.5-14.5 14.5-14.5 4.2 0 8.2 1.9 11 5 7.8 8.7 19.7 13.7 32.7 11.9 16.8-2.2 30.1-15.9 32-32.7 2.5-22.5-15.1-41.5-37.1-41.5-11 0-20.9 4.7-27.7 12.3-2.8 3.1-6.7 4.9-10.9 4.9-8 0-14.5-6.5-14.5-14.5v-111.6h111.6c8.1 0 14.5-6.5 14.5-14.5 0-4.1-1.8-8.1-4.9-10.9-7.6-6.8-12.3-16.6-12.3-27.6 0-22 19-39.6 41.5-37.1 16.8 1.8 30.5 15.2 32.8 32 1.7 12.9-3.3 24.8-12 32.7-3.1 2.8-5 6.7-5 10.9 0 8 6.5 14.5 14.5 14.5h111.6v111.6c0 8-6.4 14.5-14.5 14.5-4.2 0-8.1-1.9-10.9-5-7.9-8.7-19.7-13.6-32.7-11.9-16.8 2.2-30.1 15.9-32 32.7-2.5 22.5 15.1 41.6 37.1 41.6 11 0 20.8-4.8 27.7-12.3 2.8-3.1 6.7-5 10.8-5 8.1 0 14.5 6.5 14.5 14.5v111.6h-111.6c-8 0-14.5 6.5-14.5 14.5 0 4.2 1.9 8.1 5 10.9 7.5 6.8 12.3 16.7 12.3 27.7 0 22-19 39.5-41.6 37.1-16.8-1.9-30.5-15.3-32.7-32-1.7-13 3.3-24.9 11.9-32.7 3.1-2.9 5-6.8 5-11 0-8-6.4-14.5-14.5-14.5z\"]];\n  var PLACE = [[52, -16, 80, 14], [-24, 34, 96, -22], [46, 26, 74, 32], [-8, -20, 84, -12], [58, 38, 92, 24], [4, 18, 78, -32]]; // left %, top %, width %, rotate deg\n  var PCOL = [[\"#2f7d5b\", 0.95], [\"#0c1e18\", 0.8], [\"ACC\", 0.9], [\"#c6f26b\", 0.85], [\"#0a6b46\", 0.95], [\"#fbf8f1\", 0.85]];\n  function piece(i, accent, sx, ox) {\n    var p = PIECES[i % 3], q = PLACE[i % 6], c = PCOL[i % 6], k = sx || 1, o = ox || 0;\n    return '<span class=\"ef-acs__pc\" aria-hidden=\"true\" style=\"position:absolute;left:' + (o + q[0] * k).toFixed(1) + '%;top:' + q[1] + '%;width:' + (q[2] * k).toFixed(1) + '%;transform:rotate(' + q[3] + 'deg);color:' + (c[0] === \"ACC\" ? accent : c[0]) + ';opacity:' + c[1] + ';pointer-events:none\"><svg viewBox=\"' + p[0] + '\" aria-hidden=\"true\" focusable=\"false\" style=\"display:block;width:100%;height:auto\"><path fill=\"currentColor\" d=\"' + p[1] + '\"/></svg></span>';\n  }\n  function art(i, a) {\n    var c = \"#fbf8f1\", d = \"#0c1e18\";\n    var p = i % 6;\n    if (p === 0) return \"radial-gradient(circle at 70% 30%, \" + a + \" 0 18%, transparent 19%), linear-gradient(160deg, #005236, \" + d + \")\";\n    if (p === 1) return \"conic-gradient(from 210deg at 35% 65%, #005236, \" + a + \", \" + c + \", #005236)\";\n    if (p === 2) return \"repeating-linear-gradient(120deg, #005236 0 12px, \" + d + \" 12px 24px)\";\n    if (p === 3) return \"radial-gradient(circle at 30% 35%, \" + a + \" 0 20%, transparent 21%), radial-gradient(circle at 62% 62%, \" + c + \" 0 18%, transparent 19%), linear-gradient(200deg, #0a6b46, \" + d + \")\";\n    if (p === 4) return \"radial-gradient(ellipse 36% 26% at 50% 44%, \" + c + \" 0 99%, transparent 100%), linear-gradient(190deg, #005236, \" + a + \")\";\n    return \"radial-gradient(circle, \" + a + \" 0 2.5px, transparent 3px) 0 0 / 16px 16px, linear-gradient(145deg, #005236, \" + d + \")\";\n  }\n  function clamp(v, a, b) { return v < a ? a : v > b ? b : v; }\n  function build() {\n    colsEl.textContent = \"\";\n    cols = [];\n    for (var c = 0; c < 3; c++) {\n      var col = document.createElement(\"div\"); col.className = \"ef-acs__col\";\n      for (var k = 0; k < opts.tiles; k++) {\n        var n = c * opts.tiles + k;\n        var t = document.createElement(\"div\"); t.className = \"ef-acs__tile\";\n        t.style.aspectRatio = \"1 / \" + RATIOS[c][k % 6];\n        t.style.background = art(n, opts.accent);\n        t.insertAdjacentHTML(\"afterbegin\", piece(n, opts.accent));\n        var l = document.createElement(\"span\"); l.className = \"ef-acs__t\"; l.textContent = NAMES[n % NAMES.length];\n        t.appendChild(l); col.appendChild(t);\n      }\n      colsEl.appendChild(col); cols.push(col);\n    }\n    measure();\n  }\n  function measure() {\n    if (dead) return;\n    viewH = view.clientHeight;\n    stage.style.height = viewH + \"px\";\n    space.style.height = Math.round(viewH * 3.2) + \"px\";\n    ranges = cols.map(function (c) { return Math.max(0, c.offsetHeight - viewH); });\n    target = view.scrollTop;\n    kick();\n  }\n  function kick() { if (!raf && !dead) raf = requestAnimationFrame(tick); }\n  function tick() {\n    raf = 0;\n    if (dead) return;\n    target = view.scrollTop;\n    var prev = cur;\n    cur += (target - cur) * (reduce ? 1 : opts.ease);\n    if (Math.abs(target - cur) < 0.05) cur = target;\n    var v = reduce ? 0 : cur - prev;\n    var max = Math.max(1, space.offsetHeight - viewH);\n    var p = clamp(cur / max, 0, 1);\n    var sk = clamp(v / 40, -1, 1) * 5 * opts.skew;\n    for (var i = 0; i < cols.length; i++) {\n      var y = i % 2 ? -ranges[i] + p * ranges[i] : -p * ranges[i];\n      cols[i].style.transform = \"translate3d(0,\" + y.toFixed(2) + \"px,0)\" + (reduce ? \"\" : \" skewY(\" + (i % 2 ? sk : -sk).toFixed(2) + \"deg)\");\n    }\n    if (cur !== target || Math.abs(v) > 0.01) kick();\n  }\n  function onScroll() { kick(); }\n  function update(next) {\n    var prev = opts;\n    opts = Object.assign({ background: \"#0c1e18\", accent: \"#e6ff55\", ease: 0.1, skew: 1, gap: 12, tiles: 4 }, opts, next || {});\n    opts.tiles = Math.max(3, Math.min(6, Math.round(opts.tiles)));\n    opts.ease = clamp(+opts.ease, 0.04, 0.4);\n    opts.skew = clamp(+opts.skew, 0, 1.5);\n    opts.gap = clamp(+opts.gap, 2, 32);\n    wrap.style.background = opts.background;\n    wrap.style.setProperty(\"--ef-acc\", opts.accent);\n    wrap.style.setProperty(\"--g\", opts.gap + \"px\");\n    if (prev.tiles !== opts.tiles || prev.accent !== opts.accent) build();\n    else if (prev.gap !== opts.gap) measure();\n  }\n  function destroy() {\n    dead = true;\n    if (raf) cancelAnimationFrame(raf);\n    raf = 0;\n    offs.forEach(function (f) { f(); }); offs = [];\n    if (ro) { ro.disconnect(); ro = null; }\n  }\n  view.addEventListener(\"scroll\", onScroll, { passive: true });\n  offs.push(function () { view.removeEventListener(\"scroll\", onScroll); });\n  if (window.ResizeObserver) { ro = new ResizeObserver(function () { measure(); }); ro.observe(view); }\n  else { window.addEventListener(\"resize\", measure); offs.push(function () { window.removeEventListener(\"resize\", measure); }); }\n  update(o);\n  return { update: update, destroy: destroy };\n}"
  }
}