[yungsamd17]

Tool cards react again, sliders got fill trails, and the Icon Maker color picker is now the shared one.

What changed

• Tool card hover — the @media (hover: hover) gate added in fix(tools): smooth mobile scrolling and stop sticky card hover #45 left the cards inert on browsers that misreport hover support. Back to a plain .tool-item:hover.
• Card wash — the hover gradient is clipped to the padding box, so it can no longer bleed through the translucent border or past the rounded corners.
• Sliders — new shared src/scripts/range-fill.ts paints the filled trail up to the thumb (WebKit via a CSS variable, Firefox via ::-moz-range-progress); thumbs are white with a soft glow. Icon Maker's hue slider keeps its rainbow track.
• One color picker — the Icon Maker canvas picker moved into src/scripts/tools/color-picker.ts + src/components/ColorField.astro. QR Generator's foreground/background use it instead of the native OS color box, and Icon Maker's own fields use the same component. Also fixed the picker's HSV→RGB conversion, which returned the wrong channel for the 120°–180° sector.
• Accessibility — anchors get a :focus-visible ring (tool cards and footer links are anchors and had none), and prefers-reduced-motion: reduce now disables transitions and animations while keeping the busy spinner.
• Cleanup — explicit transition properties instead of transition: all, hex colors normalized to lowercase everywhere, .color-field.cp-disabled promoted to the shared stylesheet, docs/README.md architecture map refreshed.

Touched areas

• Styles: src/styles/tool.css, src/styles/global.css, src/styles/tools/icon-maker.css
• New: src/components/ColorField.astro, src/scripts/tools/color-picker.ts, src/scripts/range-fill.ts
• Scripts: src/scripts/tools/icon-maker.ts, src/scripts/tools/qr-generator.ts, src/scripts/tools/lib.ts
• Pages: src/pages/tools/icon-maker.astro, src/pages/tools/qr-generator.astro, src/pages/design.astro
• Docs: AGENTS.md, docs/README.md

Testing

• npm run build — 12 pages built
• npx astro check — 0 errors
• Color picker exercised in a DOM harness (hex input, invalid hex, popup open/close, hue slider, per-field isolation)
• Before/after screenshots — to be added

Built with minimax-m3.1-flash-free in the OpenCode harness, running in T3 Code.

[github-actions]

✅ PR Checks passed

Typecheck (npx astro check) and production build both green.