Animated loader · deepseek-v4.1-flash

Let me build this. Let me first check the directory and gsap file.

Let me build the index.html. I'll create a loading animation with rounded geometric shapes and five dots. Let me design a nice composition.

Plan:
- Dark background (#0d1117 or #0a0a12)
- A group of 3-4 rounded shapes (squares/circles) that morph scale, position, border-radius
- Row of 5 dots with staggered opacity/scale
- GSAP timeline ~4.5s repeat: -1, yoyo maybe or seamless loop
- Controls: Pause/Resume toggle, Restart
- Center everything

For seamless repeat without abrupt jump, the timeline should start and end at the same state (yoyo or design matching endpoints). Easiest: repeat: -1 with a timeline whose start and end states match. Use yoyo: true for a smooth back-and-forth but then pause/resume still works. However yoyo with repeat:-1 is seamless. But requirement "full sequence lasts 3 to 6 seconds and repeats without abrupt jump". A yoyo could work but that just reverses. Let's design keyframes that return to start.

Better: create timeline that animates shapes and dots, then at end returns to initial. Use `repeat: -1, repeatDelay: 0`. We'll ensure final values equal initial values.

Let me design shapes in a container:
- A rounded square that rotates/morphs into circle.
- A pill/ellipse.
- A triangle? "rounded geometric shapes" - I can use border-radius to make morphs.

Let me create 4 shapes positioned around center, each animating position, scale, borderRadius.

For dots: 5 dots, stagger with scale/opacity pulsing.

Timeline duration ~4.5s.

Controls: 
- Pause button toggles, text changes.
- Restart: tl.restart() and set paused false? Requirement restart returns to beginning. If paused, restart then resume probably. I'll make restart set paused false and button label to Pause.

Important: "repeats without ... a growing number of animation instances" — use single timeline, don't create new tweens on restart.

Let me also add a progress indicator maybe. Keep simple.

Let me write the file.

I'll use a `#stage` centered with flex. The composition is a fixed-size box ~360px.

Shapes: I'll use divs with classes.

Choreography (timeline total ~4.5s):
- shapes initial: scattered, scale small.
- pulse/expand.

Let me define concrete keyframes. I'll use gsap.fromTo or just tl.to chains.

Let me think about a nice look. Background dark radial gradient. Shapes with gradient fills (linear-gradient) and box-shadow glow. Colors: cyan #22d3ee, violet #a78bfa, pink #f472b6, emerald #34d399.

Composition: a central big rounded square that morphs into circle and rotates; two orbiting smaller shapes.

Let me make it simpler and robust: four shape divs, each with its own timeline sequence, coordinated.

I'll write:

```
const tl = gsap.timeline({repeat:-1, defaults:{ease:"power2.inOut"}});
```

Shapes:
- #s1: large, center-ish, borderRadius from 30% to 50% (circle), scale 1 -> 1.2 -> 1, rotation 0->180->360.
- #s2, #s3: orbit around.
- #s4.

Positions via x/y.

Dots: `gsap.utils.toArray('.dot')`, tl.to(dots, {y:-14, scale:1.4, opacity:1, stagger:{each:0.12, from:"start"}, duration:0.6}, 0.3). Then back down. Then another wave.

To ensure loop seamless, final states must match initial. I'll set initial CSS states and use fromTo to return.

Actually simplest seamless approach: make timeline symmetric so end == start. Use fromTo on each tween explicitly with both from and to states that start where CSS defines. Then at end reset to those start values with a final tween. Or use `tl.to(..., ...)` and at the very end animate back.

Let me just build a sequence and add a final segment that returns everything to initial, making total ~4.8s. Then repeat.

Let me define initial state inline via gsap.set at load and record. Actually I'll set all start values with gsap.set and use .to() and end by animating back to those same values.

Plan:

```
gsap.set(shapes, {transformOrigin:"50% 50%"});
gsap.set('#s1', {x:0,y:0,scale:0.7,rotation:0,borderRadius:'24%',opacity:0.9});
...
```

Then timeline:

Phase A (0 - 1.2s): shapes bloom outward, scale up, border radius morph.
Phase B (1.2 - 2.4s): rotate and converge.
Phase C (2.4 - 3.6s): swap positions.
Phase D (3.6 - 4.8s): return to initial.

That's complex to get exactly back. Alternative: use a helper that at end sets to initial via .set() — but a .set at the end causes a jump if not equal. If we animate back smoothly it's fine.

Simplest robust: design the timeline so the last tweens explicitly return each property to its start value, and all earlier tweens are intermediate. Let me do that.

Let me define for each shape start values:
- s1 (big rounded square, center): x0=0,y0=0, scale=0.6, rotation=0, borderRadius='28%'
- s2 (top-left): x=-95,y=-70, scale=0.5, rotation=0, borderRadius='50%'
- s3 (top-right): x=95,y=-70, scale=0.5, rotation=0, borderRadius='20%'
- s4 (bottom): x=0,y=95, scale=0.5, rotation=0, borderRadius='40%'

Timeline:
0.0-1.4: all scale to bigger, move outward slightly, rotate.
1.4-2.8: border radius morph, s1 scale pulse.
2.8-4.0: move to swapped positions.
4.0-4.8: return to start values (explicit .to with start values).

Hmm but "return to start" at 4.0-4.8 must set exactly the start values. Yes.

Actually a cleaner and very reliable seamless loop: use `yoyo: true` on the whole timeline with repeat:-1. Then whatever the end state is, it plays back to start smoothly. The requirement says sequence lasts 3-6s and repeats without abrupt jump. yoyo gives a palindrome repeat which is seamless. But then "repeats" — a yoyo repeat is acceptable. However a pure yoyo may look like it rewinds. It's smooth though. I think designing a proper forward loop is nicer but more error-prone. Let me do the forward loop with explicit return; I can verify.

Let me just carefully craft. I'll use a function to build.

Actually let me use a technique: capture initial state, and add return tweens automatically. Too fancy. I'll write explicit.

Let me write the code.

Structure:
```html
<div class="wrap">
  <div class="stage">
    <div class="shape s1"></div>
    ...
  </div>
  <div class="dots">
    <span class="dot"></span> x5
  </div>
  <div class="controls">
    <button id="pauseBtn">Pause</button>
    <button id="restartBtn">Restart</button>
  </div>
</div>
```

Stage is position relative, size 300x300, shapes absolute centered.

Shapes use `left:50%;top:50%;margin-left:-60px;margin-top:-60px` for centering then transform x/y.

Let me set shape sizes: s1 120x120, s2/s3/s4 72x72.

Colors with gradients.

Now the timeline. Let me write it:

```js
const tl = gsap.timeline({repeat:-1, defaults:{ease:"power2.inOut"}, onRepeat:()=>{}});
```

I want total 4.8s. Use labels.

Let me define start states via gsap.set, then tl.to() phases. Since gsap records from current values at tween start, and I explicitly return to start at end, loop is seamless.

Shapes tweens:

Phase 1 (0 -> 1.2): 
tl.to('.s1',{scale:1,rotation:90,duration:1.2},0)
tl.to('.s2',{x:-120,y:-95,scale:0.9,rotation:-90,duration:1.2},0)
tl.to('.s3',{x:120,y:-95,scale:0.9,rotation:90,duration:1.2},0)
tl.to('.s4',{x:0,y:120,scale:0.9,rotation:-90,duration:1.2},0)

Phase 2 (1.2 -> 2.4):
morph border radius, and swap positions:
tl.to('.s1',{borderRadius:'50%',scale:1.25,duration:1.2},1.2)
tl.to('.s2',{x:0,y:120,scale:0.7,borderRadius:'50%',duration:1.2},1.2)
tl.to('.s3',{x:-120,y:-95,...},1.2)  // hmm s3 to s2's pos
tl.to('.s4',{x:120,y:-95,...},1.2)

Phase 3 (2.4 -> 3.6): continue rotate, return positions partly:
tl.to('.s1',{rotation:270,scale:0.85,duration:1.2},2.4)
tl.to('.s2',{x:-120,y:-95,duration:1.2},2.4)
tl.to('.s3',{x:0,y:120,duration:1.2},2.4)
tl.to('.s4',{x:120,y:-95,duration:1.2},2.4)

Phase 4 (3.6 -> 4.8): return to exact start:
tl.to('.s1',{scale:0.6,rotation:360,borderRadius:'28%',duration:1.2},3.6)
tl.to('.s2',{x:-95,y:-70,scale:0.5,rotation:0,borderRadius:'50%',duration:1.2},3.6)
tl.to('.s3',{x:95,y:-70,scale:0.5,rotation:0,borderRadius:'20%',duration:1.2},3.6)
tl.to('.s4',{x:0,y:95,scale:0.5,rotation:0,borderRadius:'40%',duration:1.2},3.6)

But rotation at start is 0, at end of phase4 set to 360 — that's visually same as 0, seamless. Good. For s2/s3/s4 rotation returns to 0; but they were rotated -90/90 etc. Setting back to 0 means rotating backwards, fine.

Wait, at t=3.6 s2 rotation is -90 (from phase1, unchanged). Returning to 0 rotates back. s3 from 90 to 0. s4 from -90 to 0. Good.

But s1 rotation: phase1 to 90, phase3 to 270, phase4 to 360. seamless (360≡0). Good.

Dots: I want a repeating wave within the 4.8s. Could do two waves. 
Wave1 at 0.2: dots up scale/opacity, stagger 0.1, duration 0.5, then down at 0.9.
Wave2 at 2.6 similar.
Ensure at end dots back to initial (y0, scale1, opacity .35 maybe). Let me set initial opacity 0.35, scale 0.8. Dots pulse to opacity1 scale1.3.

Actually dots should also have staggered motion. Let me do:

```
const dots = gsap.utils.toArray('.dot');
tl.to(dots,{y:-16,scale:1.35,opacity:1,duration:0.55,ease:'power2.out',stagger:0.1},0.2)
  .to(dots,{y:0,scale:0.8,opacity:0.35,duration:0.55,ease:'power2.in',stagger:0.1},0.75)
  .to(dots,{y:-16,scale:1.35,opacity:1,duration:0.55,ease:'power2.out',stagger:0.1},2.6)
  .to(dots,{y:0,scale:0.8,opacity:0.35,duration:0.55,ease:'power2.in',stagger:0.1},3.15);
```

That ends at 3.7, then idle until 4.8. Fine. Ends at initial. Good.

Hmm, "row of five dots with staggered motion or opacity" — satisfied.

Maybe add a subtle rotating conic ring? Optional. Keep it.

Also add progress bar? Not required. I'll add a small progress line maybe nice but not needed. I'll add an optional progress ring? Keep simple: maybe a thin progress bar under controls. Actually let's add a progress bar driven by tl.progress() via onUpdate. Nice touch.

Let me add `.progress` bar and update width. But careful: restart resets. Use gsap ticker or onUpdate.

I'll add:
```
tl.eventCallback('onUpdate', ()=> progressFill.style.width = (tl.progress()*100)+'%');
```
But progress jumps on repeat (from 100 to 0) which is fine.

Controls:
```
pauseBtn.onclick = () => {
  if (tl.paused()) { tl.resume(); pauseBtn.textContent='Pause'; }
  else { tl.pause(); pauseBtn.textContent='Resume'; }
};
restartBtn.onclick = () => {
  tl.restart(); // restart resumes playback? gsap restart() plays from start
  tl.paused(false)? 
};
```
Actually `tl.restart()` restarts and plays (it calls play unless paused? Let me recall: restart(includeDelay, suppressEvents) restarts the timeline and resumes it if paused? GSAP `restart()` sets time to 0 and plays. Yes it resumes. Then set button text to 'Pause'.

But if paused, restart() — GSAP docs: "restart() ... Note: restart() does not automatically resume a paused animation; you must call resume() or play() after." Hmm I think actually restart() does play. Let me be safe:
```
restartBtn.onclick = () => { tl.restart(); tl.paused(false); tl.play(); pauseBtn.textContent='Pause'; }
```
Wait tl.paused(false) is same as resume. I'll do tl.restart(); tl.play(); That ensures playing.

Actually restart() might already play. Calling play() after is harmless.

Pause freezes current position; resume continues — yes.

Let me also make sure GSAP doesn't use any external. Good.

Now write file.

Let me pick font system stack. Fine.

I'll write it now.

One more consideration: "repeats without ... a growing number of animation instances" — we create one timeline and reuse; controls call pause/resume/restart, no new tweens. Good.

Let me write.

Now let me run it in the browser and inspect.

Looks good. Now let me sample the timeline at several moments. I'll pause at specific times using window.__loader.tl and seek. Let me use browser actions. I can't run arbitrary JS directly except via click/type. Hmm, the browser tool doesn't have an eval action. I can use `inspect` to see DOM. But to sample timeline I need to control time.

Options: Use inspect which returns DOM text. I could use the `browser` action with key/click. But to seek to a specific time, I could temporarily modify the HTML to expose seeking via query param, or just use the motion action to capture frames over time.

Actually the browser tool has "motion" which captures frames. Let me use that to see animation over time. Also screenshot at intervals.

Let me take screenshots after waiting. The tool doesn't have a wait action. Hmm. The `motion` action likely captures multiple frames. Let me try motion.

Alternatively, I can add a debug hook that seeks based on URL hash, but simpler: pause and seek via a small script injected... not possible.

Let me use motion to observe. Also click pause and resume to verify.

Actually to sample specific timeline moments, I can temporarily add code that reads location.hash and seeks. But reload happens. Let me just rely on motion frames and screenshots.

Let me do motion first.

The animation is running and shapes change. Now I need to test Pause/Resume and Restart. Let me click Pause, then screenshot, then click Resume. Also restart.

Let me click Pause at (543, 629). Then take screenshot, then wait via motion maybe to confirm freeze. But screenshots at different times: if paused, multiple screenshots should be identical. Let me do that.

First click Pause.

Paused. Button text changed to Resume. Now take a screenshot after some delay to confirm it's frozen. I don't have wait, but motion captures frames with delay. Let me use motion while paused — frames should be identical. Actually motion may resume? No, it just captures. Let me do a screenshot again after some elapsed time. The tool calls have time between them. Let me just take screenshot.

Frozen identically — pause works. Now click Resume and verify motion continues. Click at (543,629). Then motion.

Resumed, same position (continues from paused state). Good. Now test Restart: click at (653,629). It should return to beginning composition. Let me click and screenshot.

Restart returns to the starting composition: central blue rounded square scale 0.6, dots dim/small, progress near 0. Good.

Now, I want to verify the seamless loop and that there's no growing animation instances. Let me run for a while (motion) and check it doesn't drift. Also verify the loop end state matches start. Since I explicitly return to start values, it should. 

One thing to check: at loop boundary, dots' second wave ends at 3.7s with stagger from "end". The last dot to finish is dot index 0 (from end) at 3.15 + 0.4 + 0.55 = 4.1s. Actually stagger from end means index 4 first, index 0 last: index0 offset = 4*0.1=0.4, so ends at 3.15+0.4+0.55=4.1. Timeline duration is 4.8. Fine, all settled by 4.1.

Shape tweens all end at 4.8. Good.

Let me let it run and check the loop point by observing motion frames around the boundary. Hard to time exactly. I'll trust the explicit return. But let me verify programmatically somehow. I can use the `inspect` action but it only gives text. 

Actually I could add a temporary debug element that shows timeline time and shape values, then inspect. But that would require editing and reloading, then reverting. Given time budget, maybe not necessary. But it'd be good to confirm seamless. Let me instead reason: The timeline is linear (no yoyo), each tween's end value equals the gsap.set start value, so at t=4.8 state equals t=0 state. When it repeats, the repeat re-renders from time 0 with same values. Seamless. 

However, there's a subtlety: GSAP's repeat resets internal tween states and re-renders from the start. Since tween start values are captured from the rendered state at the time the tween starts. At the moment of repeat, the timeline jumps back to 0 and renders all tweens at progress 0. For the first tweens, their "from" is the recorded start values (set at build time? No). Actually GSAP tweens record start values lazily at first render, but when a timeline repeats, it re-renders and the tweens use their cached start values from the first run. This is standard and works. Good.

Potential issue: For s1 rotation, end at 360 then repeat to 0 — no visual jump. Good.

Now, does the animation keep a constant instance count? Yes, single timeline with repeat:-1. No new tweens. Good.

Let me verify the loop visually by capturing many frames spanning >4.8s. Motion captured only 4 frames over ~1.7s. Let me do motion again a couple times, or use a longer approach. Let me do a screenshot after some time and confirm it's mid-animation, then again. Actually I've already seen good variety.

Let me check for console errors — only the sandbox warning, no JS errors. Good.

One improvement: The requirement says "group of rounded geometric shapes that smoothly change scale, position, and corner radius". Yes. "row of five dots with staggered motion or opacity". Yes.

I think it's complete. Let me do one more motion to observe loop and dot stagger. Let me run motion twice.

Actually, let me verify the loop seam more rigorously by temporarily exposing timeline time. I could use the browser `type` action? No.

Alternatively, I can inject a check via editing the file to add a debug readout, run, then remove. Time budget is fine (used maybe 5 min). Let me add a small hidden debug hook that logs state at repeat boundaries? Actually simpler: add an element displaying `tl.time()` and shape transforms, then inspect. But inspect returns DOM text — useful.

Hmm, but I'd need to remove it after. Let me do a cleaner approach: temporarily append a query-param-controlled debug that seeks. Actually, I can just trust it. But the task explicitly asks to "Sample the timeline at several moments" and verify smooth transitions. I did via motion frames.

Let me at least confirm repeat boundary continuity with a motion capture over a longer period. Motion gave 4 frames per call ~1.7s. Two calls ~3.4s. Not enough for 4.8s. Let me call motion and then immediately motion again, then compare first frame of second call to see if near loop. Hard to be precise.

I'll trust the math and the visual checks. Let me do a final reload and motion to ensure fresh state works. Also check that after restart it continues playing (the screenshot after restart showed progress ~0 and shapes at start; it should continue). Let me take a screenshot now (some seconds later) to confirm it advanced past start.

Interesting — this screenshot shows the composition back near the start (shapes small, dots dim) but progress bar at ~75%. Wait, the shapes are near start values but progress is 75%. That suggests that at 75% (t=3.6s) phase D begins and shapes are returning to start. At t=3.6 they should be at the phase C end state, not start. But here they look already at start. Hmm.

Wait, actually the screenshot might be at t≈4.6 where shapes nearly back to start, progress 75%? Progress 75% of 4.8 = 3.6s. At exactly 3.6 phase D just starts, shapes should be at phase C end: s1 scale 0.85 rotation 270; s2 at (-120,-95); s3 at (0,120); s4 at (120,-95). But the screenshot shows s2 top-left, s3 top-right, s4 bottom — which is the start layout, not phase C. 

Hmm, wait. Let me reconsider. Actually the progress bar width maybe ~75%? It's hard to tell. The fill spans from x=490 to x=703 out of 490 to 710, so ~96%? Actually progress track from 490 to 710 = 220px. Fill from 490 to ~703 = 213px = 97%. So near end of loop, t≈4.66. At that point shapes nearly back to start. That makes sense! Good, no contradiction.

So it's near the end of the loop, shapes returning to start. 

Now let me observe the loop boundary. Let me take a couple screenshots quickly. Actually the fact that near end it matches start confirms seamless.

Let me verify that it wrapped and continues. Another screenshot.

Hmm, this is a strange frame. The shapes appear clustered/converged near center, and progress ~72%. This is likely during phase C where shapes circulate and overlap. s1 big circle center, s2 (teal) top-left, s3 pink lower-right of center, s4 teal small right. That's a mid-circulation state. Fine — it looks a bit like they overlap, which is intended "swap positions". It's a smooth transition.

Wait, the progress went from ~97% to ~72%? That's odd — time should increase, not decrease, unless it looped (97% -> wrap -> 72% after ~0.7s? no, 72% of 4.8 = 3.46s, that's a big jump). Hmm, maybe my progress reading was wrong. The previous screenshot fill looked nearly full but maybe I misjudged. Actually the previous one at 490-703 while track 490-710. This one 490-675. So previous ~97%, this ~84%? Let me recompute: 675-490=185/220=84%. 703-490=213/220=97%. Going 97% -> 84% would mean a loop happened and then only ~0.6s elapsed, but the screenshot interval seems short. Actually the time between my tool calls could be a few seconds. If loop wrapped at 97%, then 84% is 4.03s into the new loop — plausible if ~4s elapsed. But the visual at 84% (t=4.03) should be phase D returning to start, not clustered. 

Hmm, the clustered frame doesn't match t=4.03. Unless progress fill is not accurate. Let me not over-analyze; the progress bar update may lag or my pixel estimate is off. The important thing: animation is running, changing, and loops.

Actually wait — the clustered look could be phase C/D. At t=3.46 (72%), phase C: s1 rotating, s2 heading to (-120,-95) from (0,120), passing near center; s3 heading to (0,120) from (-120,-95), passing near center; s4 heading to (120,-95) from (120,-95) stays. So overlap near center is expected mid-transition. Good, matches. So this frame is ~72%, and previous ~97%. The decrease means a loop occurred. Fine.

Everything looks good. Let me verify no console errors on a fresh reload and that the gsap global loaded. The dom shows buttons, console only warning. 

I'm fairly confident. Let me do a final check: ensure file references gsap.min.js correctly and is self-contained. Let me view the file head and confirm. Already did.

One more: the addendum says the runner will inline gsap.min.js into the final artifact. We use plain script tag with exact filename. Good.

I think we're done. Let me write a brief report.

Actually, let me double check there isn't an issue with the animation "growing number of animation instances". Since controls only pause/resume/restart, no new tweens. Good.

Let me also confirm the loop duration is between 3-6s: 4.8s. Good.

Final answer report.