Align font sizes with production baseline

Signed-off-by: kenny lopez <klopez4212@gmail.com>

desktop/src/shared/lib/fontSizePreference.test.mjs

@@ -32,7 +32,7 @@ test("persists and applies the selected font size across the app", () => {
   assert.equal(preference.getFontSize(), "smaller");
   assert.equal(values.get(preference.FONT_SIZE_STORAGE_KEY), "smaller");
   assert.equal(attributes.get("data-font-size"), "smaller");
-  assert.equal(style.fontSize, "15px");
+  assert.equal(style.fontSize, "16px");
 });
 
 test("previews a font size without changing the saved preference", () => {
@@ -42,11 +42,11 @@ test("previews a font size without changing the saved preference", () => {
   assert.equal(preference.getFontSize(), "smaller");
   assert.equal(values.get(preference.FONT_SIZE_STORAGE_KEY), "smaller");
   assert.equal(attributes.get("data-font-size"), "larger");
-  assert.equal(style.fontSize, "18.7px");
+  assert.equal(style.fontSize, "20.114286px");
 
   preference.previewFontSize(null);
   assert.equal(attributes.get("data-font-size"), "smaller");
-  assert.equal(style.fontSize, "16.5px");
+  assert.equal(style.fontSize, "17.6px");
 });
 
 test("initializes from the stored font size", () => {
@@ -55,5 +55,5 @@ test("initializes from the stored font size", () => {
   preference.initializeFontSizePreference();
   assert.equal(preference.getFontSize(), "larger");
   assert.equal(attributes.get("data-font-size"), "larger");
-  assert.equal(style.fontSize, "17px");
+  assert.equal(style.fontSize, "18.285714px");
 });

desktop/src/shared/lib/fontSizePreference.ts

@@ -6,10 +6,14 @@ export type FontSize = "smaller" | "default" | "larger";
 export const FONT_SIZE_STORAGE_KEY = "buzz.appearance.fontSize";
 export const DEFAULT_FONT_SIZE: FontSize = "default";
 
+/**
+ * Root sizes that map Tailwind's production `text-sm` size (0.875rem) to the
+ * three app-wide 14px, 15px, and 16px steps.
+ */
 const BASE_FONT_SIZE_PX: Record<FontSize, number> = {
-  smaller: 15,
-  default: 16,
-  larger: 17,
+  smaller: 14 / 0.875,
+  default: 15 / 0.875,
+  larger: 16 / 0.875,
 };
 
 const listeners = new Set<() => void>();
@@ -33,7 +37,9 @@ function readStoredFontSize(): FontSize {
 }
 
 function rootFontSizePx(size: FontSize): number {
-  return Math.round(BASE_FONT_SIZE_PX[size] * textZoomFactor * 1_000) / 1_000;
+  return (
+    Math.round(BASE_FONT_SIZE_PX[size] * textZoomFactor * 1_000_000) / 1_000_000
+  );
 }
 
 function applyFontSize(size: FontSize): void {

desktop/src/shared/styles/globals/theme.css

@@ -7,14 +7,14 @@
      * Inbox, and the composer. The app-wide Font size preference and Cmd +/-
      * scale these rem values; Conversation density overrides only spacing.
      */
-    --conversation-message-font-size: 0.9375rem;
+    --conversation-message-font-size: 0.875rem;
     --conversation-message-line-height: 1.25rem;
-    --conversation-author-line-height: 1.0625rem;
+    --conversation-author-line-height: 1rem;
     --conversation-body-gap: 0.125rem;
     --conversation-row-padding-block: 0.375rem;
     --conversation-paragraph-gap: 0.5rem;
     --conversation-list-item-gap: 0.375rem;
-    --conversation-timestamp-font-size: 0.6875rem;
+    --conversation-timestamp-font-size: 0.75rem;
     --conversation-timestamp-line-height: 1rem;
     --background: 220 23.08% 94.9%;
     --foreground: 234 16.02% 35.49%;