bjornmelin/web-css-animations
plugins/web-motion/skills/web-css-animations/SKILL.md
Use this skill for Browser CSS transitions, keyframes, scroll-driven animations, registered properties, discrete transitions, reduced motion, and performance-safe CSS motion. Trigger on CSS transition, @keyframes, animation-timeline, prefers-reduced-motion, @starting-style, transition-behavior, CSS animation. Do not use for near-miss tasks outside these boundaries; route to adjacent motion or platform skills when they own the implementation.
$ install --global
skillsauthnpx skillsauth add bjornmelin/dev-skills web-css-animationsInstall this skill globally with one command. Works with Claude Code, Cursor, and Windsurf.
Security Scan Results
3 of 9 scanners reported clean
Some scanners were skipped, did not run, or reported a non-clean status. Review each row below.
3
Scanners Passed
9
Scanners in report
Clean
TrivyContainer and dependency vulnerability scanner
95%
Clean
SemgrepStatic code analysis for vulnerabilities
95%
Clean
mcp-scan (Snyk)Model Context Protocol security validation
95%
Skipped
Snyk (dep)Open source security scanning
50%
Skipped
Socket.devSupply chain security analysis
50%
Skipped
VirusTotalMulti-engine malware detection
50%
Skipped
CrowdStrikeAdvanced threat intelligence
50%
Skipped
OSV-ScannerOpen Source Vulnerability database check
50%
Skipped
OWASP Dep-Check
50%
Last scanned: Jun 10, 2026, 3:27 AM85.8s21 files scanned
SKILL.md
- name:
- web-css-animations
- description:
- >-
- license:
- MIT
Web CSS Animations
Browser CSS transitions, keyframes, scroll-driven animations, registered properties, discrete transitions, reduced motion, and performance-safe CSS motion.
Operating Contract
Use this skill as a compact router plus domain checklist. Load references only when the current task matches their condition. Do not cite local scrape paths, machine cache paths, or hidden source locations. Verify API details against the target repo's installed package versions before editing.
Source Order
- Inspect the target repo's installed packages, framework/runtime versions, local design tokens, accessibility policy, and existing motion patterns.
- Use the bundled references below for skill-specific gotchas and copied source excerpts.
- Use official current docs/package source as API truth when local code or bundled notes are version-sensitive.
Decision Boundaries
- Use CSS first for two-state UI motion.
- Move to WAAPI when an Animation object or seeking is needed.
- Move to GSAP for complex imperative choreography.
Workflow
- Identify the state driver and animated properties.
- Use explicit transition-property lists and product motion tokens.
- Add reduced-motion behavior beside the motion.
- Guard new CSS with @supports or local browser policy.
Gotchas
- transition: all hides expensive accidental properties.
- Unregistered custom properties animate discretely.
- animation shorthand resets animation-timeline, so set timeline after shorthand.
Bundled Resources
references/css-motion-field-guide.md- CSS transition/keyframe field guide. Read before implementing ordinary CSS state motion.references/browser-support-and-accessibility.md- Support, @supports, and reduced-motion notes. Read for newer CSS features or accessibility review.references/property-performance-matrix.md- CSS property performance matrix. Read for transform, opacity, layout, paint, filter, shadow, and text animation risk.references/scroll-driven-and-view-timelines.md- Scroll-driven and view-timeline CSS motion. Read when usinganimation-timeline,scroll(),view(), timeline ranges, or CSS scroll-driven animation instead of JavaScript scroll handlers.references/discrete-entry-exit-transitions.md- Discrete entry and exit transitions. Read when animatingdisplay,content-visibility, popovers, dialogs,@starting-style, ortransition-behavior.references/docs-css-modern-motion-notes.md- Source-backed notes and links. Load when exact upstream API detail may have changed.references/docs-mdn-css-animations.md- MDN CSS animations routing notes. Load when reviewing@keyframesandanimation-*behavior.references/docs-mdn-css-transitions.md- MDN CSS transitions routing notes. Load when reviewingtransition-*behavior.references/docs-mdn-prefers-reduced-motion.md- MDN reduced-motion routing notes. Load when reviewing CSS reduced-motion behavior.references/docs-browser-motion-performance.md- Source-backed browser performance notes. Load when checking property or compositor risk.references/index.md- Complete reference inventory and routing summary.references/source-ledger.md- Source list, checked date, and copy policy.references/provenance.json- Machine-readable source and local-resource metadata.scripts/audit.mjs- Self-contained audit CLI; rundoctorbeforescanwhen setup is unclear.assets/templates/web-css-animations-audit-report.md- Audit response/report template.assets/templates/web-css-animations-review-checklist.md- Manual review checklist.assets/examples/web-css-animations-starter.css- Starter fixture/example for this skill.evals/trigger-queries.json- Trigger/near-miss eval set for description tuning.evals/evals.json- Task-quality evals with assertions.
Audit CLI
node scripts/audit.mjs doctor --root . --format json
node scripts/audit.mjs scan --root . --format markdown
node scripts/audit.mjs scan --root . --format json --output web-css-animations-audit.json
Treat script findings as leads. Verify every finding against current code before changing behavior or reporting it as valid.
Closeout
Before finalizing, run the repo's focused validation command, this skill's audit CLI when relevant, and any browser/device/manual proof required by the changed surface. Report commands run, findings fixed, findings skipped with reasons, and residual risk.
Related Skills
bjornmelin/repo-modernizer
development
VerifiedTrustedCommunity
Repo/monorepo modernization: dependency upgrades, security fixes, deprecation cleanup, framework migrations, dependency-native refactors, and verified hard-cut simplification.
2SKILL.mdUpdated Jun 11, 2026
bjornmelin/web-waapi
development
VerifiedTrustedCommunity
Use this skill for Browser Web Animations API: Element.animate(), Animation, KeyframeEffect, playback control, generated keyframes, cancel/finish, commitStyles, and cleanup. Trigger on Element.animate, WAAPI, Web Animations API, KeyframeEffect, Animation object, commitStyles. Do not use for near-miss tasks outside these boundaries; route to adjacent motion or platform skills when they own the implementation.
2SKILL.mdUpdated Jun 11, 2026
bjornmelin/web-three-r3f
tools
VerifiedTrustedCommunity
Use this skill for Three.js, React Three Fiber, Drei, Canvas/createRoot lifecycle, loaders, GLTF, useFrame, disposal, SSR/client boundaries, DPR, and browser proof. Trigger on Three.js, THREE, @react-three/fiber, @react-three/drei, R3F Canvas, useFrame, GLTF, WebGLRenderer. Do not use for near-miss tasks outside these boundaries; route to adjacent motion or platform skills when they own the implementation.
2SKILL.mdUpdated Jun 11, 2026
bjornmelin/web-tailwind-motion
development
VerifiedTrustedCommunity
Use this skill for Tailwind CSS v4 transition, animation, duration, easing, motion-safe/motion-reduce, @theme motion tokens, and static class safety. Trigger on Tailwind animation, transition-all, motion-safe, motion-reduce, @theme, animate-, duration-. Do not use for near-miss tasks outside these boundaries; route to adjacent motion or platform skills when they own the implementation.
2SKILL.mdUpdated Jun 11, 2026