Create a dark atmospheric background with drifting vertical light folds, screen-blended glow, and a concentrated luminous corner or lower-edge bloom.
SkillScore100Maintained
Automatic
◆Frontend / UI pack
Last verified 8/10/2026
What it changes
Passed 22 of 22 test cases with the skill, and 15 of 22 without it.
Without skill68%
With skill100%
Checks it passed that the model alone missed
The response sets a dark navy or charcoal base background color.
The response increases fold opacity toward the lower focal region.
The response adjusts the total count of rendered vertical light folds.
and 5 more in the full report
7 fixed15 passed either way0 still failing0 broke
Pass-rate lift
+32 pp
Tokens
+9%
Agent turns
0%
Response time
-21%
Model gemini-3.6-flashMeasured 8/10/2026v122 of 22 cases passed with skill
Tokens, turns and time describe resource use, not a dollar price.
See it in action
One of 7 test cases the skill fixed. Same model, same prompt, with and without the skill.
1 of 7
Prompt
We need to adjust the density of our dark atmospheric canvas background so it feels less cluttered on mobile screens. Which visual parameter controls this atmospheric density?
What was checked, without and with the skill
Checked
Without skill
With skill
The response adjusts the total count of rendered vertical light folds.
Missed
Passed
case-12 · gemini-3.6-flash · 8/10/2026 · answers are capped and redacted
What's inside
The instructions your model reads when the skill loads.
SKILL.md37 linessingle file
Atmosphere Background Skill
Use When
Create a dark atmospheric background with drifting vertical light folds, screen-blended glow, and a concentrated luminous corner or lower-edge bloom.
Workflow
Scope
Apply this only to the immersive background layer, not to the full page layout, typography, or unrelated WebGL/particle systems.
Use it when the design needs a moody atmospheric backdrop with fluid light curtains or folds instead of geometric grids, blobs, or literal illustrations.
Visual target
Create a deep near-black background with soft vertical light folds drifting across the frame like illuminated fabric, fog sheets, or light curtains.
Build the glow from multiple overlapping vertical bands so the background feels layered and spatial rather than flat.
Let brightness accumulate more strongly toward one area, especially the lower right or lower edge, so the scene has a cinematic focal glow instead of uniform brightness.
Keep the palette restrained: dark navy or charcoal base, then derive the glow from the design's primary color or strongest accent color. If no clear brand color exists, a cool cyan-blue atmosphere is acceptable.
Implementation guidance
Prefer canvas or shader-driven rendering for this effect instead of static CSS gradients when motion is required.
Use multiple tall overlapping bands or folds with slow sine-wave drift so the structure reads as moving atmospheric light rather than hard columns.
Use screen or additive-style blending so the overlapping folds brighten naturally where they cross.
Shape each fold with vertical gradients that fade at the top and intensify toward the bottom or focal corner.
Add a subtle radial glow overlay near the focal edge or corner to reinforce depth and the main luminous area.
Motion should stay slow and meditative: gentle drift, slight intensity modulation, no noisy flicker or rapid pulsing.
Tuning knobs
Fold count: add or reduce the number of vertical folds depending on how dense the atmosphere should feel.
Drift: control horizontal sway amplitude and speed to keep motion calm.
Brightness focus: place the strongest glow near a corner, edge, or lower quadrant instead of spreading it evenly across the whole frame.
Color: tint the folds with the active design accent while preserving a dark, premium base.
Softness: adjust overlap width, gradient falloff, and post-glow strength so the background feels luminous but not washed out.
Avoid
Flat multi-stop gradients with no layered fold structure.
Loud rainbow color transitions or bright full-frame glow that competes with foreground content.
Hardcoded cyan if the design clearly uses another primary color.
Fast turbulence, noisy particle motion, or obvious repeating patterns that break the calm atmospheric look.