BlockNote's internal CSS sets `.bn-editor { background-color: var(--bn-colors-editor-background); }`
using its own hardcoded variables (#ffffff light, #1f1f1f dark). Our `.bn-container` rule set
`background: var(--bg-primary)` but this didn't cascade to `.bn-editor` which has its own rule.
Override the BlockNote internal CSS variables (`--bn-colors-editor-background` etc.) on
`.bn-container` so BlockNote's own rules pick up our vault theme colors. CSS custom properties
cascade normally, and our selector specificity (2 classes) matches BlockNote's dark theme rule
(1 class + 1 attribute) — source order wins since our CSS loads after BlockNote's.
Fixes: editor content area now seamlessly blends with sidebar and container in any vault theme.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>