The border was the thing making every note look the same

A note card carried a 1px tint border. Measured against its own fill, that
line was a 1.56-2.09 contrast in dark mode while the fill managed only
1.03-1.05 against the board — so the loudest thing on every card was an
identical line in an identical place, and a field of them read as a grid of
outlined rectangles however different the colours inside were.

Removed from the note card on both surfaces. `border` survives for panels,
banners, the update card and the pickers: those are single elements, not a
field of them.

What replaces it differs by theme, because elevation does.

  Light leans on a shadow. An untagged card is `bg-red-50` on a `neutral-50`
  board — a 1.04 contrast that can only read as a card by sitting above one.
  The web goes `shadow-sm` -> `shadow`; Android had no shadow at all and gets
  2dp.

  Dark cannot use one, black on near-black. So the subdued fills moved onto
  the card surface instead: `{hue}-950` composited at 0.18 over #171717 and
  baked, rather than the same hue at 0.25 over the near-black board. An
  untagged card now sits where the plain white card always sat (1.11-1.14
  against the board, against `bg-neutral-900`'s 1.10) while carrying LESS hue
  than before — chroma 7-17 where the old ramp had 10-23.

Subtler and more visible at once, which is only a contradiction if subtlety
has to come from lightness. Here it comes from chroma, and lightness is left
to say "this is a card". Which also reframes the two weights: in dark they
now sit within a hair of each other (red: 1.11 vs 1.12) and differ threefold
in colour (chroma 10 vs 41).

The chosen ramp is untouched — the operator signed those colours off, and a
ramp somebody likes is not something to redo while fixing something else.
Light was already built this way: `-50` and `-100` are both white plus a
different amount of hue.

Body text still measures 14.3-16.4 against the 4.5 it needs, meta 6.9-7.1
against 3.0.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

frontend/src/components/NoteCard.vue

@@ -222,7 +222,7 @@ onBeforeUnmount(() => document.removeEventListener("mousedown", onDocMousedown))
 <template>
   <div
     ref="root"
-    class="group relative mb-4 break-inside-avoid rounded-xl border p-3 shadow-sm transition hover:shadow-md"
+    class="group relative mb-4 break-inside-avoid rounded-xl p-3 shadow transition hover:shadow-md"
     :class="[
       noteCardClasses(note),
       dragging ? 'opacity-40' : '',
@@ -233,6 +233,14 @@ onBeforeUnmount(() => document.removeEventListener("mousedown", onDocMousedown))
     ]"
     :data-note-id="note.id"
   >
+    <!-- No `border`. The hue border that used to frame every card outshouted the fill
+         it framed and turned the board into a grid of identical outlines — see the
+         measurements above NOTE_CARD_CLASSES. `shadow` rather than `shadow-sm` because
+         it is now the ONLY thing separating a light-mode card from the board: an
+         untagged card is `bg-red-50` on `bg-neutral-50`, a 1.05 contrast that reads as
+         a card purely by sitting above one. Dark mode gets no shadow worth the name
+         against a near-black board, which is why the subdued fills moved onto the card
+         surface instead. -->
     <img
       v-if="firstImage"
       :src="firstImage.url"