Layout

React · Reference cheat sheet

📋 Overview

Layout in React is ordinary DOM + CSS (Flexbox, Grid, modules, Tailwind). Components compose shells: header, sidebar, main, footer — often via nested routes or layout wrappers.

🔧 Core concepts

• Shell components — AppLayout, AuthLayout wrap page content with children.
• CSS approach — CSS Modules, Tailwind, styled-components, plain CSS — pick one stack.
• Responsive — media queries or container queries; avoid hard-coded pixel-only UIs.
• Portals — modals/tooltips via createPortal to escape overflow/stacking contexts.

💡 Examples

import type { ReactNode } from "react";

export function AppLayout({ children }: { children: ReactNode }) {
  return (
    <div className="app">
      <header className="app-header">Brand</header>
      <div className="app-body">
        <aside className="app-nav">Nav</aside>
        <main className="app-main">{children}</main>
      </div>
    </div>
  );
}

.app {
  min-height: 100dvh;
  display: flex;
  flex-direction: column;
}
.app-body {
  flex: 1;
  display: grid;
  grid-template-columns: 240px 1fr;
}
.app-main {
  padding: 1.5rem;
}

⚠️ Pitfalls

• Nesting too many layout wrappers without clear ownership.
• Fixed heights that break on mobile keyboards / dynamic viewport.
• Forgetting min-width: 0 on flex/grid children that overflow.

🔗 Related

• pages.md — page content inside layouts
• children.md — layout slots
• root.md — app root
• file_structure.md — where layouts live