Fix button alignment by removing negative margin

Remove mr-[-3em] from AddLocationButton, AddMonthButton, and PrintButton
to improve visual alignment and spacing consistency.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

app/ui/PrintButton.tsx

@@ -22,7 +22,7 @@ export const PrintButton: React.FC<PrintButtonProps> = ({ yearMonth }) => {
         onClick={handlePrintClick}
         data-tip={t("print-codes-tooltip")}
       >
-        <span className='flex self-center mr-[-3em]'>
+        <span className='flex self-center'>
           <PrinterIcon className="h-[1em] w-[1em] cursor-pointer text-4xl" />
           <span className="ml-1 mt-[.4em] text-xs text-left leading-[1.2em] w-[6em]">{t("print-codes-label")}</span>
         </span>