CSS Layout Debugging Strategy

Systematic approach to diagnosing layout issues when elements overflow, hide behind others, or behave unexpectedly.

First Principle: CSS layout problems are almost always caused by stacking context, positioning, or box model misunderstandings. The browser is following rules - you need to understand which ones.

Step 1: Visual Diagnosis

• Add temporary borders: * { border: 1px solid red !important; }
• Use background colors to identify element boundaries
• Enable browser outline: * { outline: 1px solid blue; }

Step 2: Inspector Analysis

• Elements Panel: Right-click element → Inspect
• Computed Styles: See final calculated values
• Box Model Diagram: Visual representation of padding/margin/border
• Layout Tab: Shows flexbox/grid container properties

Step 3: Stacking Context Investigation

• Check z-index values and stacking contexts
• Look for position: relative/absolute/fixed
• Identify transform, opacity, filter creating new contexts

Mental Model: Think of CSS as layers in Photoshop - understand which layer each element lives on and why.

Related: CSS Stacking Context, Browser Dev Tools Layout