[pathanin]

What changed

Restyle (src/style.css): the UI now uses a flat / hairline style:

• Neutral greys written as black at an alpha (white at an alpha in dark mode); no blue tint on surfaces.
• 1px hairline borders; shadows only on floating things (toast, tooltip, dialogs, drop card, the checked segmented option), always paired with a hairline ring. The canvas has a hairline only.
• 14px control text (was 13px).
• The style's tokens sit at the top of style.css; the app's old variable names map onto them, so the other rules mostly didn't change. --check-a / --check-b are untouched (view.js reads them).

Default tool: the app starts with the brush instead of the pencil (state.js, main.js).

Calls made within the style (also in task.md, "Layout and look")

• Muted text is 60% black, not the style's 47%, which misses 4.5:1 on the panels.
• Blue stays only where it marks the picture or focus: focus rings, object selection and hover, handles, text box, resize ghost, drop zone, sliders, checkboxes. The rail's active tool is a 10% grey tint; primary buttons and the checked anchor are near-black (near-white in dark).
• Palette chips no longer scale up on hover; the 24px target gets a 5% tint instead.
• Dark mode was built on the same principle (the style only defines light).
• No sliding segmented thumb (would need markup and JS); the checked option gets the thumb's look.

Testing

• npm test: 95/95.
• e2e on the built app (Chrome): smoke (332/332), history, preview, filledge, objects, alpha, libs, pwa — all pass, including the "bars fit at 600px" and "help fits at 1280×800" checks with the larger text.
• Compared before/after screenshots (light, dark, rectangle options, resize dialog, help, 900px).
• Not checked in WebKit / Safari.