What is CSS Grid?

CSS Grid is a two-dimensional layout system that allows you to create grid-based layouts with rows and columns. Unlike Flexbox, which is primarily one-dimensional, Grid enables you to control both rows and columns simultaneously, making it perfect for complex layouts.

Basic Grid Setup

To create a grid, you simply need to set the display property to grid on a container element:

.container {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    grid-template-rows: auto;
    gap: 20px;
}

Grid Template Columns and Rows

The grid-template-columns and grid-template-rows properties define the structure of your grid. You can use various units:

• fr (fractional unit): Divides available space proportionally
• px, em, rem: Fixed sizes
• auto: Sizes based on content
• minmax(): Sets minimum and maximum sizes

/* Example: Three equal columns */
grid-template-columns: 1fr 1fr 1fr;

/* Example: Mixed units */
grid-template-columns: 200px 1fr 2fr;

/* Example: Responsive with minmax */
grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));

Grid Gap

The gap property (or grid-gap for older browsers) adds spacing between grid items:

.container {
    gap: 20px; /* Same gap for rows and columns */
    /* Or separately: */
    row-gap: 20px;
    column-gap: 30px;
}

Grid Item Placement

You can control where items are placed in the grid using line numbers or named lines:

.item {
    grid-column-start: 1;
    grid-column-end: 3;
    grid-row-start: 1;
    grid-row-end: 2;

    /* Shorthand */
    grid-column: 1 / 3;
    grid-row: 1 / 2;

    /* Span syntax */
    grid-column: span 2;
}

Grid Areas

Named grid areas make layouts more readable and maintainable:

.container {
    display: grid;
    grid-template-areas:
        "header header header"
        "sidebar main main"
        "footer footer footer";
    grid-template-columns: 200px 1fr 1fr;
    grid-template-rows: auto 1fr auto;
}

.header { grid-area: header; }
.sidebar { grid-area: sidebar; }
.main { grid-area: main; }
.footer { grid-area: footer; }

Responsive Grid Layouts

CSS Grid excels at creating responsive layouts. Here are some common patterns:

Auto-Fit and Auto-Fill

/* Auto-fit: collapses empty tracks */
grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));

/* Auto-fill: keeps empty tracks */
grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));

Media Query Breakpoints

/* Mobile first */
.container {
    grid-template-columns: 1fr;
}

/* Tablet */
@media (min-width: 768px) {
    .container {
        grid-template-columns: repeat(2, 1fr);
    }
}

/* Desktop */
@media (min-width: 1024px) {
    .container {
        grid-template-columns: repeat(3, 1fr);
    }
}

Alignment in Grid

Grid provides powerful alignment properties:

.container {
    /* Align items within their grid area */
    align-items: start | end | center | stretch;
    justify-items: start | end | center | stretch;

    /* Align the entire grid */
    align-content: start | end | center | stretch | space-around | space-between;
    justify-content: start | end | center | stretch | space-around | space-between;
}

.item {
    /* Align individual items */
    align-self: start | end | center | stretch;
    justify-self: start | end | center | stretch;
}

Practical Examples

Example 1: Card Grid

.card-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    padding: 2rem;
}

Example 2: Holy Grail Layout

.layout {
    display: grid;
    grid-template-areas:
        "header header header"
        "nav main aside"
        "footer footer footer";
    grid-template-columns: 200px 1fr 200px;
    grid-template-rows: auto 1fr auto;
    min-height: 100vh;
}

Example 3: Magazine Layout

.magazine {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    grid-template-rows: repeat(3, 200px);
    gap: 1rem;
}

.featured {
    grid-column: 1 / 3;
    grid-row: 1 / 3;
}

Best Practices

1. Use Grid for 2D layouts: When you need to control both rows and columns
2. Combine with Flexbox: Use Grid for page layout, Flexbox for component layout
3. Use semantic HTML: Grid doesn't change document structure
4. Test responsiveness: Always test your grid layouts on different screen sizes
5. Use named areas: Makes code more maintainable and readable

Browser Support

CSS Grid is supported in all modern browsers. For older browsers, you can use feature queries:

@supports (display: grid) {
    .container {
        display: grid;
        grid-template-columns: repeat(3, 1fr);
    }
}

@supports not (display: grid) {
    .container {
        display: flex;
        flex-wrap: wrap;
    }
}

Conclusion

CSS Grid Layout is a powerful tool that simplifies complex layout challenges. With its two-dimensional capabilities, it's perfect for creating modern, responsive web layouts. Start with the basics, practice with real projects, and you'll soon master this essential CSS feature.