It’s not valid CSS, so does not work. CSS is not SCSS: if you’re writing SCSS, make sure you turn that on in the CodePen settings for that pen
You did not define a hover pseudo-class on #input to change the Submit input element.
transition: background-color 1s;
Two things wrong. First, you only want to target the input with id=“submit”. Also, you have a typo. There is no such property named “bakground-color”.