Unlock the Power of Nested Layouts with CSS Subgrids

Can you believe it’s been over 5 years since CSS Grid Layout exploded onto the web design scene? As someone who has worked in web development for over a decade, I still remember the impact of transitioning from makeshift grid frameworks like Bootstrap to the native two-dimensional grid capabilities CSS Grid unlocked.

Yet as transformative as CSS Grid has been, no specification is perfect right out of the gate. Even the mightiest tools have room to grow. As adoption spread, the web design community discovered Grid’s limitations when it came to nested grid alignments across breakpoints.

Enter CSS subgrids – the natural evolution of grid-based web design with the introduction of CSS Grid Level 2.

In this post, I’ll share my insights as a seasoned web development expert on what exactly subgrids are, what layout challenges they solve, and why they represent the next generation of intuitive website design.

Let’s start from the beginning…

What Are CSS Subgrids?

CSS subgrids allow you to nest a grid container inside a grid item of the parent grid. This grid item becomes a subgrid that inherits the alignment structure and sizing of tracks from that parent level.

This connects all grid levels together, rather than having nested grids act as separate self-contained layouts. Content across subgrid levels stay aligned to one unified master grid for the overall container element.

For example, say you have a 12 column wide grid defined on a parent container:

.page-grid {
  display: grid;
  grid-template-columns: repeat(12, 1fr);
}

Now if you make a grid item span 6 columns and turn it into a subgrid:

.subgrid { 
  grid-column: span 6;
  display: grid;
  grid-template-columns: subgrid; 
}

The .subgrid will have 6 column tracks by default without restating that explicitly. And those 6 columns align to the 12 columns of .page-grid thanks to inheritance!

This connects the alignment across the entire page while allowing you to nest grids seamlessly.

Why Are Subgrids Important?

Now you may be wondering – why not just keep nesting regular grids without subgrids involved?

Well, once you start building complex, responsive layouts with nested grids, some major pain points emerge:

Misaligned Grid Items

Without subgrids, elements between nested grids can become offset across breakpoints. Subgrids keep everything locked together through inheritance.

Overwhelming Reconfiguration

Tweaking grid column sizes requires updating every level – tedious and error-prone! Subgrids cut out this duplication.

Unpredictable Layout Shifts

Moving one nested grid often impacts other grids’ positioning since they are not in sync. Subgrid alignments remain unified since all grids tie back to the parent.

This year’s CSS survey found over 50% of developers are already using CSS grids, with more onboarding each year. And naturally, more grids means more nesting – and more need for alignment control.

Subgrids solve these issues to unlock more seamless nested grid designs, as seen here:

/* Without subgrids */ 

vs

/* With subgrids */

It’s a revelation for grid layouts – no wonder subgrids are being called CSS Grid’s most exciting upgrade since its launch!

Step-By-Step: Building a Subgrid

Ready to see a subgrid in action for yourself? Follow along as I walk through a simple example:

Parent Grid Container

.page-grid {
  display: grid;
  grid-template-columns: 1fr 3fr 1fr; 
}

Nested Grid Item & Subgrid

.subgrid {
  grid-column: 2;
  display: grid; 
  grid-template-columns: subgrid;
}

Result: Columns inherit 3 fraction unit width from parent!

While basic, this shows the power of subgrid inheritance at work – now imagine this applied to multi-level, responsive layouts!

Supporting Subgrids Across Browsers

As an emerging feature, subgrid support varies across browsers. It’s supported out of the box in Firefox and Safari, with Chrome and Edge running tests to integrate support.

For production sites, I recommend these steps to progressively enhance subgrids:

1. Feature query to enable subgrids for supported browsers
2. Provide fallback CSS for non-supporting browsers
3. Use JavaScript to mimic subgrid functionality

I lean on BrowserStack to instantly test across 3000+ real mobile and desktop browsers to catch layout issues. This helps build truly resilient, cross-compatible websites.

Browser	Version	Subgrid Support
Safari	v12+	Yes
Firefox	v71+	Yes
Chrome	Under Consideration	No

Now that you understand the immense layout potential unlocked by subgrids, I predict their usage will only spread year after year. By linking grids together across nested levels, they provide fine-grained alignment control previously out of reach.

The web design community asked for more advanced grid capabilities – our wishes have been granted with subgrids. It’s an exciting time to see CSS still innovating new ways to intuitively design intricate interfaces.

I’d love to hear your thoughts on adopting subgrids for your current or upcoming projects! Feel free to reach out with any other grid-related questions.