message: use pattern color as text shadow color
  need to confirm with design that this makes sense
diff: border-top-left-radius: var(--boxel-border-radius);
  padding: var(--boxel-sp);
  color: var(--header-text-color);
  + text-shadow: 0px 1px var(--header-pattern-color);
  font: var(--boxel-font-xs);
  letter-spacing: var(--boxel-lsp);
  }
  