feat(design): modern blue ink accent + stronger paper grain

Shift signal from oxblood (#7A2320) to modern blue (#1D4ED8),
signal-quiet from warm rose to pale blue wash. Bump body grain
opacity 0.35 → 0.6 so the paper texture actually reads.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

web/src/design/tokens.ts

@@ -1,9 +1,9 @@
 /**
- * AnyDrop design tokens — Paper & Envelope direction.
+ * AnyDrop design tokens — Paper & Ink direction.
  *
  * Principles:
- *  - Paper-warm neutrals + ink black, never slate/grey-blue.
+ *  - Paper-warm neutrals + ink black; visible paper grain via body::before.
- *  - ONE signature accent (oxblood). Use sparingly — accent earns its rarity.
+ *  - ONE signature accent (modern blue, like fountain-pen ink on paper).
  *  - Serif display + neutral sans body. Type does the heavy lifting, not color.
  *  - Shadows are textural, not dramatic. Radii stay sharp (2–6px).
  *  - Motion curves favor paper physics (ease-out-expo), never bounce.
@@ -16,8 +16,8 @@ export const color = {
   inkMuted: "#6B635A",
   inkFaint: "#A89F93",
 
-  signal: "#7A2320",
+  signal: "#1D4ED8",
-  signalQuiet: "#F3E2E0",
+  signalQuiet: "#E3EAF5",
 
   ok: "#3E6B4A",
   warn: "#8B6914",

web/src/index.css

@@ -18,16 +18,16 @@
     -moz-osx-font-smoothing: grayscale;
     text-rendering: optimizeLegibility;
   }
-  /* Paper texture — very subtle noise, 2% opacity */
+  /* Paper grain — fibrous noise, warm brown tint, multiply */
   body::before {
     content: "";
     position: fixed;
     inset: 0;
     pointer-events: none;
     z-index: 0;
-    background-image: url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' width='200' height='200'><filter id='n'><feTurbulence type='fractalNoise' baseFrequency='0.85' numOctaves='2' stitchTiles='stitch'/><feColorMatrix values='0 0 0 0 0.1 0 0 0 0 0.09 0 0 0 0 0.08 0 0 0 0.55 0'/></filter><rect width='100%' height='100%' filter='url(%23n)' opacity='0.18'/></svg>");
+    background-image: url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' width='320' height='320'><filter id='n'><feTurbulence type='fractalNoise' baseFrequency='0.78' numOctaves='2' stitchTiles='stitch'/><feColorMatrix values='0 0 0 0 0.12 0 0 0 0 0.1 0 0 0 0 0.08 0 0 0 0.7 0'/></filter><rect width='100%' height='100%' filter='url(%23n)' opacity='0.32'/></svg>");
     mix-blend-mode: multiply;
-    opacity: 0.35;
+    opacity: 0.6;
   }
   #root {
     position: relative;
@@ -47,9 +47,9 @@
   .mono {
     font-family: "JetBrains Mono", "Berkeley Mono", ui-monospace, monospace;
   }
-  /* Selection: signal on quiet paper */
+  /* Selection: modern blue ink on paper */
   ::selection {
-    background: #7a2320;
+    background: #1d4ed8;
     color: #f5f0e6;
   }
 }

web/tailwind.config.js

@@ -10,8 +10,8 @@ export default {
         ink: "#1A1714",
         "ink-muted": "#6B635A",
         "ink-faint": "#A89F93",
-        signal: "#7A2320",
+        signal: "#1D4ED8",
-        "signal-quiet": "#F3E2E0",
+        "signal-quiet": "#E3EAF5",
         ok: "#3E6B4A",
         warn: "#8B6914",
         fail: "#8A3324",