A structured lesson workspace with readable content, hands-on examples, and a clean path to completion.
| Concern | What to inspect | Typical failure |
|---|---|---|
| Core behavior | Multi-Column Layouts | Multi-column is content flow, not a grid of independent cards. Items can split between columns unless you control breaks. |
| Production test | Real content and constraints | The rule works only for the demo values |
| Maintenance | Scope and override path | A later fix creates another exception |
The useful mental model here is practical: how CSS columns flow prose into newspaper-like vertical columns and where the model differs from grid. When a rule looks obvious but the browser produces something else, start by identifying which constraint or rendering phase is actually winning.
A good CSS change narrows the problem. Use columns for editorial text and reference content; use grid for component placement. This keeps the rule understandable when content, theme, or viewport conditions change later.
<style>.demo { column-count:2; }</style><main class="demo">Example content</main>
In production, Multi-column is content flow, not a grid of independent cards. Items can split between columns unless you control breaks. That is the kind of bug that survives visual spot checks because the stylesheet is syntactically valid while the layout contract is wrong.
<style>.demo { column-width:18rem; }</style><main class="demo">Example content</main>
Engineering judgment: Use columns for editorial text and reference content; use grid for component placement.
<style>.demo { column-gap:2rem; }</style><main class="demo">Example content</main>
Example 3 is useful here because it demonstrates multi-column layouts under a concrete input rather than as an abstract property list.
<style>.demo { break-inside:avoid; }</style><main class="demo">Example content</main>
Example 4 is useful here because it demonstrates multi-column layouts under a concrete input rather than as an abstract property list.
Finish the lesson once you have worked through the material. This awards ★ 30 XP.