JavaScript (encriptador) [closed]

application that encrypts texts.
The encryption “keys” we will use are as follows:
The letter “e” is converted to “enter”.
The letter “i” is converted to “imes”.
The letter “a” is converted to “ai”.
The letter “o” is converted to “ober”.
The letter “u” is converted for “ufat”.
Requirements:
Must work only with lowercase letters
No letters with accents or special characters must be used.
It must be possible to convert a word for the encrypted version also return an encrypted word for its original version.
For example:
“gato” => “gaitober”.
gaitober” => “gato”.
The page must have fields for
The page must have fields for inserting the text to be encrypted or decrypted, and the user must be able to choose between the two options.
The result should be displayed on the screen.
Extras:
A button that copies the encrypted/decrypted text for the transfer section, i.e. it should have the same functionality as ctrl+C or the “copy” option in the applications menu.

Here is the link to GitHub, where the program files are (I only have the HTML and I need to finish the CSS)
https://github.com/tetey0422/encriptador

An encryptor, but I need to improve my css

This is how the page is supposed to look on its different screens
https://www.figma.com/design/trP3p5nEh7XUyB3n2bomjP/Alura-Challenge—Desaf%C3%ADo-1—L%C3%B3gica?node-id=0-1&t=J3eaw8cZjFaQHPC0-0