296 Characters (preserves UI, margins, sizing and placeholder text)

[sidnz]

296 characters:

Demo: https://github.com/umpox/TinyEditor/blob/b0694b20467aea032b4d99fb84ef855f014f48d5/README.md

I'm not a fan of removing placeholder text, the goal is to still be clear to the end user what each input box does, therefore the code has mostly be minimised while mostly preserving UI.

• Using regex to generate repetitive HTML
• Use of template literals
• Using custom single character HTML selectors
• Use of [id] selector and * wildcard selector
• Use of document.write()
• Generate single character ID from as first character from placeholder text

UI Changes:

• font-size: 18 removed, however everything else remains.