98.css

98.css is a design system for building faithful recreations of old UIs, specifically those that resemble Windows 98.

The website provides a CSS library that allows you to style your interfaces to resemble the classic Windows 98 design. It emphasizes the usage of semantic HTML and accessibility, making it easy to create buttons, checkboxes, option buttons, group boxes, text boxes, sliders, dropdowns, windows, tabs, tree views, and table views with the desired retro look.

98.css also offers examples and code snippets to guide you in implementing these components.