fix: Set css_style fallback
diff --git a/erpnext/templates/emails/birthday_reminder.html b/erpnext/templates/emails/birthday_reminder.html
index fd03637..5f2f13d 100644
--- a/erpnext/templates/emails/birthday_reminder.html
+++ b/erpnext/templates/emails/birthday_reminder.html
@@ -5,13 +5,13 @@
<img
class="avatar-frame standard-image"
src="{{ person.image }}"
- style="{{ css_style }}"
+ style="{{ css_style or '' }}"
title="{{ person.name }}">
</span>
{% else %}
<span
class="avatar-frame standard-image"
- style="{{ css_style }}"
+ style="{{ css_style or '' }}"
title="{{ person.name }}">
{{ person.name[:1] }}
</span>