Building SaaS Interfaces with Next.js 16 and Tailwind CSS v4

Tailwind CSS v4 introduces major architectural modifications. The CSS-first theme configuration eliminates verbose config files, and the new build pipeline compiles pages at speeds never seen before.

What is New in Tailwind CSS v4?

• CSS-First Theme Config: Custom tokens are now configured inside standard @theme directives in your stylesheet.
• Oxide Engine: Written in Rust, providing up to 10x faster build speeds.
• Automatic Content Discovery: No content globs required; your workspace source is scanned automatically.

Sample Button Component

Let us write a standard premium button style using Tailwind v4's new variables:

export function PremiumButton({ children }) {
  return (
    <button className="bg-primary text-primary-foreground hover:bg-primary/95 transition-all px-4 py-2 rounded-lg font-medium shadow-md shadow-primary/10">
      {children}
    </button>
  );
}