File Upload in HTML & CSS

Hello friend, I would like to make a gray 9 upload image, to add it within the product selection in WooCommerce, it is for the grids of the patchwork blankets

i wrote same code but my label text stuck on top and wont come in middle

Code?!

How to show my code on websites that the users can select and copy? Like on other websites like stack overflow? What's that called?

where can i get the code/?

Sir how can I upload pdf from backend using html css interface Like choose a file option