
Skeleton Screens: Faster by Faking It
Skeleton screens create the illusion of speed by showing a wireframe-like preview of a page while content loads. They're used for full-page loads to set expectations about the layout. The footgun is showing just the app frame, which gives no structure.

Header Components: An Exception to Reusability
Treat your site header as a unique beast, not a reusable component. Its complexity—managing branding, responsive navigation, and sticky positioning—makes abstraction brittle. The footgun is reusing the entire header instead of just its internal components.

Modal Dialogs: The Focus Trap Pattern
A modal dialog is a "focus trap" that overlays the UI, forcing a user to complete a task. It's used for critical confirmations or focused inputs, like a date picker. The main footgun is failing to trap keyboard focus, letting users tab into the inert.

Style Encapsulation with Shadow DOM
Shadow DOM creates a private DOM tree for a component, acting like a one-way mirror for CSS. This prevents style collisions in complex UIs, ensuring a button's CSS doesn't break a header.

Component-Driven Development: Build UIs Bottom-Up
Component-Driven Development (CDD) builds UIs bottom-up, like assembling a car from its engine and wheels. It's used to manage complex UIs by creating small, independent components first. The footgun is building components too coupled to app-specific logic.

Controlled vs. Uncontrolled Components
A controlled component is a puppet; its parent pulls the strings via props. An uncontrolled one manages its own state. This pattern is key for coordinating siblings, like ensuring only one panel in an accordion is open.

Component Variants: One Component, Many Forms
Component variants are like Lego bricks for your UI: one block can build many things. Instead of creating a unique component for every button state or size, you define properties to manage its variations.

LCH Color: More Vivid, Predictable UI Colors
LCH is a color space that aligns with human perception. It fixes HSL's broken lightness and unlocks 50% more vivid colors on modern screens. The footgun: LCH hue angles don't match HSL's; 0° is magenta, not red, so you can't just swap them.

CSS clamp(): Fluid Sizing Without Media Queries
CSS clamp() sets guardrails for a value, letting it scale fluidly but never going outside a min/max bound. It's ideal for responsive typography, allowing font-size to grow with the viewport. The footgun: the preferred value is ignored at extreme screen sizes.

Vertical Rhythm: A Formula for Consistent Spacing
Vertical rhythm is a system for consistent spacing derived from your body text's line height. Use this calculated unit between all elements—paragraphs, lists, and after headings—to create harmony.

Spacing Scales: Using Multiples for Consistent UI
A spacing scale builds consistent UI layouts from a limited set of values, usually multiples of a base unit like 8px. It's used for everything from button padding to page gaps. The footgun is using arbitrary pixel values, which breaks the system's rhythm.

Typographic Scale: A System for Consistent Text
A typographic scale is a predefined set of font sizes and line heights that creates visual harmony. Design systems use it for consistent, readable text across devices. The footgun is adding one-off font sizes, which breaks the system's rhythm and consistency.

Theming: One Design System, Many Visual Styles
Theming lets one component library wear many visual styles, like skins on a character. You can support multiple brands or dark/light modes by swapping design tokens instead of rebuilding components.

Design Systems: From UI Kits to Business Infrastructure
A design system is business infrastructure, not just a UI kit. It translates brand consistency into measurable ROI by reducing costs and accelerating delivery.

Atomic Design: Building UIs Like Chemistry
Atomic Design is like chemistry for UIs: you build complex screens from simple, indivisible 'atoms' like buttons and inputs. It's used to create consistent design systems. The footgun is treating it as a rigid, linear process instead of a mental model.

Design System: The Whole vs. Its Parts
A design system is the parent; style guides and component libraries are its children. It's the full toolkit for building consistent products at scale, containing rules, patterns, and ready-to-use code.

A Design System is a Shared Toolbox, Not Just a Sticker Sheet
A design system is a shared toolbox of reusable UI components and rules, not just a style guide. It ensures consistency and speed when multiple teams build products at scale.