As a CSS code editor, I've been encountering issues when trying to apply custom CSS styles to specific elements. My goal is to assign a unique ID to each element in the email template, allowing for precise customization of those elements using CSS.

For example, I would like to assign an ID like #header or #button1 to elements so that I can easily style them:

#header {

background-color: #f4f4f4;

font-size: 18px;

}

#button1 {

background-color: #ff5733;

color: white;

padding: 10px;

}

However, I'm facing errors during the process and need assistance resolving them.