Just shipped: ACS — Audio Cascading Style Sheets. CSS describes how an HTML element should LOOK. ACS uses the same selectors and cascade to describe how it should SOUND. One <link rel="audiostyle"> and your buttons sound like buttons — no event handlers, no play() calls. The cascade does the wiring. button.primary { sound-on-click: pop; pitch: 1st; } input:on-input { sound: keystroke; } dialog[open] { room: small-room; } Why I built it: • Every product team re-solves UI sound design from scratch with imperative JS • CSS's cascade — selectors, specificity, inheritance — is already the right abstraction • Web Audio API is powerful but low-level; the declarative layer was missing What's in the box: • 49 calibrated presets (whole library within 4.8 dB spread) • 9 mood overlays (lofi, glassy, retro… real bitcrush ring-mod noise floor) • 8 theme packs (apple, material, retro, brutalist, cinematic, bauhaus, terminal, ambient) • AudioWorklet realtime path (sub-1ms latency) • Full cascade: !important, @media, attribute selectors, descendant combinators • @sound blocks for custom voices • CSS-var bridge — var(--token) works in any ACS value • VSCode Cursor extension — syntax, outline, audition CodeLens, knob-based sound picker • AI agent skill (Claude Code / Cursor) — turns a natural-language prompt into a paste-ready @sound ~14 KB gzipped · zero dependencies · MIT. audiocss.dev github.com/Grkmyldz148/acs npmjs.com/package/acs-audio #WebDev #JavaScript #CSS #WebAudio #UXDesign #SoundDesign #DeveloperTools #OpenSource #UIEngineering #FrontendDevelopment #npm #VSCode #Cursor #AIAgents #ClaudeCode #ACS #AudioCSS #DesignSystems