CSS Flexbox (Flexible Box Layout) and Grid (CSS Grid Layout) are two powerful layout systems in modern web design. They provide efficient ways to design complex, responsive layouts without relying on floats or positioning hacks.

• Flexbox excels at 1-dimensional layouts (rows or columns), making it ideal for aligning and distributing space among items in a container (e.g., navigation menus, card layouts).
• Grid is designed for 2-dimensional layouts (rows and columns), perfect for building entire page structures (e.g., dashboards, image galleries).

This documentation covers:

• Key differences between Flexbox and Grid.
• How to define containers and items for both systems.
• Practical examples to reinforce your understanding.

By the end, you’ll be able to confidently choose between Flexbox and Grid—or combine them—for any layout challenge.

While both Flexbox and Grid are modern CSS layout systems, they serve different purposes. Flexbox focuses on arranging items in a single dimension (row or column), while Grid provides precise control over two-dimensional layouts (rows and columns simultaneously).

• Use Flexbox when:
  • Aligning items in a row or column (e.g., navigation bars, card lists).
  • Distributing space dynamically within a container (e.g., centering content)

• Use Grid when:
  • Designing complex layouts with overlapping areas (e.g., dashboards, image galleries).
  • Needing explicit control over both rows and columns (e.g., magazine-style designs).

Live Example Code: Combining Flexbox and Grid

                        .container {
                            display: grid;
                            grid-template-columns: 1fr 1fr; /* 2-column grid */
                          }
                          
                          .item {
                            display: flex;
                            justify-content: center; /* Flexbox centers content inside grid cells */
                          }
                    

A Flexbox layout starts with a container (parent element). When you set display: flex, all direct children become flex items that follow flexbox rules.

Key Flex-Container Properties:

• flex-direction:
  • Controls the flow of items: row (left-to-right) or column (top-to-bottom).
  • Values: row | row-reverse | column | column-reverse
• justify-content:
  • Aligns items along the main axis (horizontal for rows, vertical for columns).
  • Values: flex-start | center | space-between | space-around

Live Example Code: Flexbox Container

.container {
                    display: flex;
                    flex-direction: row;
                    justify-content: space-between;
                    gap: 10px;
                }

When to Use:

• Building navigation menus
• Aligning form controls
• Creating responsive card layouts

While the flex container controls overall layout behavior, flex items (direct children) can be individually adjusted with specialized properties. These properties allow fine-tuned control over sizing, alignment, and ordering - enabling responsive layouts where some items behave differently than others in the same container.

Key Flex-Item Properties:

• flex-grow:
  • Controls how much an item grows relative to others when extra space exists.
  • Default: 0 (no growing).
• flex-shrink
  • Controls how much an item shrinks relative to others when space is limited.
  • Default: 1 (shrinks equally).
• align-self
  • Overrides the container's align-items for one item.
  • Values: flex-start | center | flex-end

Live Example Code: Flexbox Items

.item-1 {
                    flex-grow: 2;  /* Takes twice the extra space */
                    align-self: flex-end;
                  }
                  .item-2 {
                    order: -1;  /* Appears first */
                  }

When to Use:

• Creating flexible card layouts
• Reordering mobile vs. desktop layouts
• Customizing individual items in a navigation bar

CSS Grid introduces powerful two-dimensional layout capabilities. By defining a grid container, you create an explicit structure of rows and columns that child items will align to. Unlike Flexbox's single-axis approach, Grid gives pixel-perfect control over both dimensions simultaneously.

Key Grid-Container Properties:

• grid-template-columns
  • Defines column sizes (e.g., 1fr 300px auto)
  • Special units: fr (fractional), minmax()
• grid-template-rows
  • Defines row sizes (e.g., 100px auto)
• gap
  • Shorthand for row-gap and column-gap

Live Example Code: Grid-Container

.grid-container {
                    display: grid;
                    grid-template-columns: 1fr 2fr; /* Second column twice as wide */
                    grid-template-rows: 100px auto;
                    gap: 20px;
                  }

When to Use:

• Building magazine-style layouts
• Creating dashboards with multiple panels
• Any design requiring precise item placement

While the grid container defines the overall structure, grid items (direct children) can be individually positioned and sized. This allows for precise control over item placement within the grid.

Key Grid-Item Properties:

• grid-column
  • Controls horizontal placement (start/end columns)
  • Values: 1 / 3 or span 2
• grid-row
  • Controls vertical placement (start/end rows)
• grid-area
  • Shorthand for row/column placement
  • Can use named grid areas

Live Example: Grid-Item Placement

.header {
              grid-column: 1 / -1; /* Full width */
            }
            .sidebar {
              grid-row: 2 / 4; /* Spans two rows */
            }
            .featured {
              grid-area: 1 / 2 / 3 / 4; /* row-start/col-start/row-end/col-end */
            }

These official documentation and trusted resources were used in creating this guide:

• MDN Web Docs - The ultimate CSS reference: CSS: Cascading Style Sheets
• CSS-Tricks - Visual guides to Flexbox and Grid:
  • Complete Flexbox Guide
  • Complete Grid Guide
• W3C Specifications - Official standards: Flexbox, Grid
• Can I Use - Browser compatibility tables: Flexbox, Grid