Install
That writes one file:compositions/mk-background.html.
Add it to your video
It runs for 10 seconds at 1920×1080. Paste this into your composition:index.html
<div
data-composition-id="mk-background"
data-composition-src="compositions/mk-background.html"
data-start="0"
data-duration="10"
data-track-index="1"
data-width="1920"
data-height="1080"
></div>
data-start. Put it on a different timeline row with
data-track-index. See data attributes for the rest.
Source
mk-background.html
mk-background.html
<!doctype html>
<html lang="en">
<head>
<meta charset="utf-8" />
<script src="https://cdn.jsdelivr.net/npm/gsap@3.14.2/dist/gsap.min.js"></script>
<style>
*,
*::before,
*::after {
margin: 0;
padding: 0;
box-sizing: border-box;
}
body {
background: transparent;
overflow: hidden;
}
#mk-bg-root {
/* ---- mk tokens: override these in the host to re-skin the family ---- */
--mk-font: "Inter", -apple-system, sans-serif;
--mk-stage: #f5f5f7;
--mk-base: #ffffff;
--mk-blob-1: #ff7ac8;
--mk-blob-2: #45d6c8;
--mk-stage-dark: #000000;
--mk-base-dark: #0a0a0c;
--mk-blob-1-dark: #7d5cff;
--mk-blob-2-dark: #2d1b69;
--mk-radius-card: 40px;
--mk-shadow: 0 30px 80px rgba(0, 0, 0, 0.18);
position: relative;
width: 1920px;
height: 1080px;
overflow: hidden;
background: var(--mk-stage);
}
#mk-bg-root.mk-dark {
background: var(--mk-stage-dark);
}
/* The "Bar" — an animatable rounded-rect mask. Full-bleed by default,
animatable down to a floating card over the stage. */
#mk-bg-card {
position: absolute;
top: 0;
left: 0;
width: 1920px;
height: 1080px;
overflow: hidden;
border-radius: 0;
background: var(--mk-base);
box-shadow: var(--mk-shadow);
}
.mk-dark #mk-bg-card {
background: var(--mk-base-dark);
}
/* Soft radial blobs — the procedural "mesh gradient". Two oversized
radial gradients with a long falloff, drifting slowly. */
.mk-bg-blob {
position: absolute;
border-radius: 50%;
will-change: transform;
}
#mk-bg-blob1 {
background: radial-gradient(
circle closest-side,
var(--mk-blob-1) 0%,
rgba(255, 255, 255, 0) 72%
);
}
#mk-bg-blob2 {
background: radial-gradient(
circle closest-side,
var(--mk-blob-2) 0%,
rgba(255, 255, 255, 0) 72%
);
}
.mk-dark #mk-bg-blob1 {
background: radial-gradient(
circle closest-side,
var(--mk-blob-1-dark) 0%,
rgba(0, 0, 0, 0) 72%
);
}
.mk-dark #mk-bg-blob2 {
background: radial-gradient(
circle closest-side,
var(--mk-blob-2-dark) 0%,
rgba(0, 0, 0, 0) 72%
);
}
</style>
</head>
<body>
<div
id="mk-bg-root"
data-composition-id="mk-background"
data-start="0"
data-duration="10"
data-width="1920"
data-height="1080"
>
<div id="mk-bg-card">
<div id="mk-bg-blob1" class="mk-bg-blob" data-layout-allow-overflow></div>
<div id="mk-bg-blob2" class="mk-bg-blob" data-layout-allow-overflow></div>
</div>
<div
id="mk-bg-drv"
class="clip"
data-start="0"
data-duration="10"
data-track-index="0"
style="position: absolute; width: 1px; height: 1px; opacity: 0; pointer-events: none"
></div>
</div>
<script>
(function () {
window.__timelines = window.__timelines || {};
/* ---- published parameters (inspector-style CONFIG) ---- */
var CONFIG = {
scheme: "light", // "light" | "dark"
animationIn: true, // fade/settle entrance
animationOut: true, // fade exit
drift: true, // ambient blob motion
// Soft BG blobs: center as fraction of canvas, radius in px
blob1: { x: 0.28, y: 0.32, r: 950, opacity: 0.85 },
blob2: { x: 0.74, y: 0.66, r: 1100, opacity: 0.8 },
// Bar mask (rounded-rect card). demo:true plays full-bleed -> card -> full-bleed
bar: {
demo: true, // full-bleed -> rounded card -> full-bleed showcase
x: 240,
y: 140,
width: 1440,
height: 800,
roundness: 40,
},
// Content opacity + frost only matter with footage beneath the block
contentOpacity: 1,
frostBlur: 0, // px; e.g. 24 for the frosted-card look over footage
};
var W = 1920,
H = 1080,
DUR = 10;
var root = document.getElementById("mk-bg-root");
var card = document.getElementById("mk-bg-card");
var blob1 = document.getElementById("mk-bg-blob1");
var blob2 = document.getElementById("mk-bg-blob2");
if (CONFIG.scheme === "dark") root.classList.add("mk-dark");
function placeBlob(el, b) {
var d = b.r * 2;
el.style.width = d + "px";
el.style.height = d + "px";
el.style.left = b.x * W - b.r + "px";
el.style.top = b.y * H - b.r + "px";
el.style.opacity = String(b.opacity);
}
placeBlob(blob1, CONFIG.blob1);
placeBlob(blob2, CONFIG.blob2);
card.style.opacity = String(CONFIG.contentOpacity);
if (CONFIG.frostBlur > 0) {
card.style.backdropFilter = "blur(" + CONFIG.frostBlur + "px) saturate(1.4)";
}
var tl = gsap.timeline({ paused: true });
/* entrance — fade + blobs settle (power3, no bounce) */
if (CONFIG.animationIn) {
tl.from(root, { opacity: 0, duration: 0.7, ease: "power2.out" }, 0);
tl.from([blob1, blob2], { scale: 1.14, duration: 1.2, ease: "power3.out" }, 0);
}
/* ambient drift — slow sine yoyo, seek-safe timeline tweens */
if (CONFIG.drift) {
tl.to(
blob1,
{ x: 70, y: 42, duration: 2.35, ease: "sine.inOut", yoyo: true, repeat: 3 },
0.3,
);
tl.to(
blob2,
{ x: -84, y: -36, duration: 2.35, ease: "sine.inOut", yoyo: true, repeat: 3 },
0.3,
);
}
/* bar-mask demo: full-bleed -> rounded card over the stage -> full-bleed.
Offset via x/y transforms, not top/left: layout properties snap to
integer device pixels and stutter under seek-by-frame capture. The
card's CSS base is top:0/left:0, so the transform values match 1:1. */
if (CONFIG.bar.demo) {
tl.to(
card,
{
y: CONFIG.bar.y,
x: CONFIG.bar.x,
width: CONFIG.bar.width,
height: CONFIG.bar.height,
borderRadius: CONFIG.bar.roundness,
duration: 1.1,
ease: "power3.inOut",
},
3.8,
);
tl.to(
card,
{
y: 0,
x: 0,
width: W,
height: H,
borderRadius: 0,
duration: 1.0,
ease: "power3.inOut",
},
7.6,
);
}
/* exit + hard kill */
if (CONFIG.animationOut) {
tl.to(root, { opacity: 0, duration: 0.4, ease: "power2.in" }, DUR - 0.45);
}
tl.set(root, { visibility: "hidden" }, DUR - 0.02);
window.__timelines["mk-background"] = tl;
})();
</script>
</body>
</html>
background gradient minimal professional presentation.