This is an example of a classic newsletter subscription form, designed using HTML, CSS, JavaScript, and Bootstrap framework 4. The font and Bootstrap styles are imported to the code with their URLs. JavaScript methods have been used to display the subscription form when the page is refreshed. The body of the form is given a font-family style of 'Open Sans', sans-serif, and a background color of #9f9f9f. The title of the subscription form is displayed using the styles of font color as #000, text-align as center, font-family as 'Raleway', sans-serif, font-weight as 800, font-size as 30px, and text-transform style as uppercase to automatically convert the text to uppercase. The close button is given an opacity of 0.5, which gets changed to 0.8, on hover. The input text field take a box-shadow of 0 0 8px rgba(0, 0, 0, 0.1), in the focus mode. The 'Subscribe' button is given a style set of font color as #fff, background color as #353535, transition as all 0.4s, font-family as 'Raleway', sans-serif, and text-transform as uppercase. The button changes its background color to #171717, and takes a box-shadow style of 0 0 8px rgba(0, 0, 0, 0.4), in a hover event. Source:https://www.tutorialrepublic.com/snippets/preview.php?topic=bootstrap&file=classic-newsletter-signup-form