这是一套没有文字的万圣节剪贴画贴纸，采用可爱的扁平风格，轮廓线粗实。画面包括一只阅读紫色书本的奶白色幽灵、一摞三本带蝙蝠和星星图案的书、一个戴圆框眼镜并系着青绿色书签的南瓜，以及一只戴女巫帽、抱着书的黑猫。你可以在书的封面或书签上加入标题、姓名或活动日期，换成自己的文字重新制作。

Create a square 1:1 Halloween clipart sheet for a library display, on a plain, perfectly flat white background. Show exactly four separate, complete, friendly flat illustrations in a spacious 2×2 arrangement, each fully visible, clearly outlined, with generous white space between them and safe margins. Top left: a smiling little white ghost seated and reading an open book. Top right: a tidy stack of three whimsical spooky books, with simple bat, crescent-moon, and star decorations on their covers and spines; no letters or readable words. Bottom left: a cheerful orange pumpkin wearing round spectacles, with a colorful bookmark ribbon tucked behind its stem and hanging clearly down its side. Bottom right: a friendly black cat librarian in a small pointed witch hat, holding a little closed book. Use one consistent clean vector-like style: bold smooth charcoal outlines, large simple shapes, solid flat fills, minimal interior detail, crisp closed edges, subtle paper grain confined to the colored shapes only. Palette of warm pumpkin orange, soft ivory, deep plum, muted teal, and charcoal. Keep expressions kind and suitable for children and all ages. No gore, no blood, no extra objects, no border, no frame, no cast shadows or glows, no background texture, no lettering anywhere, no fake checkerboard. Ensure each illustration is isolated, readable at thumbnail size, and suitable for reuse as cutout clipart.