feat: improve custom rotate UX with larger previews and float precision

Author: Felix

docs/tools/rotate-custom.md

@@ -11,16 +11,16 @@ Rotate PDF pages by any arbitrary angle, not just 90-degree increments. Each pag
 
 1. Upload a PDF file. Thumbnails render for every page.
 2. Each page has a numeric input field showing its current rotation angle.
-3. Type any degree value (positive or negative) to rotate a specific page, or use the per-page left/right buttons for quick 90-degree adjustments.
+3. Type any degree value (positive or negative, including decimals) to rotate a specific page, or use the per-page `+`/`-` buttons for precise 1-degree adjustments.
 4. Use the **batch angle** input at the top to set a uniform rotation for all pages.
 5. Click the process button to generate the rotated PDF.
 
 ## Features
 
-- Free-form degree input per page (any integer value)
+- Free-form degree input per page (supports precise decimal values)
 - Batch angle control to set the same rotation on every page
 - Real-time preview of rotation in thumbnails
-- Per-page quick-rotate buttons for 90-degree increments
+- Per-page plus/minus buttons for 1-degree increments
 - Lazy-loaded thumbnails for performance on large documents
 
 ## Use Cases