This is a pack that personally helped me setting up my speedbridges. This is a simple pack that will basically turn your crosshair 45 degrees to the right, and if you want, easily editable. This pack does not include anything other than the crosshair change. This pack was not made for 1.16.5, but from my testing, it will work.
since there is a 150 word minimum, i will now proceed to explain exactly how i made this pack, so if you want, you can make your own changes.
so once i realised a 45 degree angled crosshair would help me, i set out to find a corsshair pack for 1.8.9 that i could just take the gui icons.png and edit that, and then just make my own mcmeta file and pack picture. so i got to editing the gui. I tried a few things, but anything under 1px kinda didnt really format right, so i just made it all 2px. i messed around for a while, and finally got a clean minimalistic design.(yes i know im overplaying this situation) so then i did some quick research of how to make the mcmeta file and stuff, and i got the title and name down, with colors. then I made the pack picture. for this, i just got a coal block, optifine zoomed it, screenshotted, then used Paint3D to cut it down to 200px by 200px. then bam. a pack. wow so amazing.