Frontend

When you think about implementing a theme system, the first instinct is to add conditional classes to every component. But what if you could swap the entire app’s color palette by changing a single CSS block — without touching any HTML? In Tailwind v4, that’s exactly what you can do. How Tailwind v4 Compiles Utility Classes Tailwind v4 compiles utility classes as CSS variable references: /* CSS generated by Tailwind v4 */ .bg-emerald-700 { background-color: var(--color-emerald-700); } .text-emerald-600 { color: var(--color-emerald-600); } .border-emerald-500 { border-color: var(--color-emerald-500); } bg-emerald-700 doesn’t hard-code #047857 — it references var(--color-emerald-700). Change that variable and every element using bg-emerald-700 updates instantly. ...

While documenting UX flows with Rails + Lookbook, I hit a moment of “something feels off.” Each Step only showed wireframe fragments, so looking at the Lookbook list gave zero sense of the overall flow. I fixed two things: Add a Mermaid flowchart Overview step to each flow Redesign all Step template structures The Problem: Lookbook Step Previews Feel Like “Context-Free Fragments” # @label Admin UX Flow # @logical_path ux_flows class UxFlows::AdminFlowPreview < ViewComponent::Preview # @label 1. Login -> Admin Dashboard def step_1_login_dashboard render_with_template end # ... end Each step_* method renders an ERB template via render_with_template. The ERB contains a wireframe with a simple step navigation bar at the top. ...

I migrated 47 ViewComponents in a Rails 8 project to a warm orange theme and built a full Lookbook preview system. Here are the real issues I ran into. Background The project already had: 47 ViewComponents across 15 categories (input, layout, navigation, card, typography, etc.) CSS Custom Properties based design tokens (tokens.css) Tailwind CSS 4 + Propshaft asset pipeline The goal was to adopt a BMC (Buy Me a Coffee) inspired warm orange theme with a dark sidebar and stone palette, and build comprehensive Lookbook previews. ...