Digest masthead: two-tone tight-tracked 'upbeat bytes' wordmark

Per user — make the text masthead read as the brand: lowercase 'upbeat bytes'
with a space but tight letter-spacing (-0.045em, not standard), in the logo's
two colours (azure #0083ad + navy #002772). Closest email-safe echo of the logo
short of a hosted PNG.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

goodnews/digest.py

@@ -104,8 +104,10 @@ def build_digest(items: list[dict], brief_date: str, unsub_url: str, base: str |
     html = (
         '<div style="max-width:600px;margin:0 auto;padding:8px 4px;'
         'font-family:-apple-system,Segoe UI,Roboto,Helvetica,Arial,sans-serif;color:#16263a">'
-        '<div style="font-family:Georgia,\'Times New Roman\',serif;font-size:30px;font-weight:700;'
-        'letter-spacing:-0.01em;margin:0;color:#16263a">upbeat bytes</div>'
+        # Two-tone lowercase wordmark echoing the logo (azure + navy), tight-tracked.
+        '<div style="font-family:\'Helvetica Neue\',Arial,sans-serif;font-size:32px;font-weight:700;'
+        'letter-spacing:-0.045em;margin:0;line-height:1">'
+        '<span style="color:#0083ad">upbeat</span> <span style="color:#002772">bytes</span></div>'
         '<div style="font-size:11px;letter-spacing:0.14em;text-transform:uppercase;color:#0083ad;'
         f'margin:5px 0 0">Daily Highlights · {escape(weekday)}</div>'
         '<p style="font-size:15px;line-height:1.5;color:#3b4754;margin:28px 0 18px">'