As a leading expert in enterprise SaaS technology, Vijay Raina has spent years navigating the challenges of building scalable and maintainable software. He has seen firsthand how CSS, the foundational layer of the web’s presentation, can become a source of immense complexity in large applications. In our conversation, we explore how modern CSS features, particularly the @scope at-rule, are providing native solutions to long-standing problems. We’ll touch on how @scope offers an alternative to rigid naming conventions like BEM, the trade-offs of utility-first frameworks, and how its unique approach to specificity and boundaries can fundamentally change how developers architect their styles for the better.
Prescriptive naming conventions like BEM often lead to long, unwieldy class names in complex applications. How does the @scope rule help developers simplify both their HTML and CSS for a component? Could you provide a step-by-step example comparing the two approaches?
This is a pain point I see constantly. Teams start with the best intentions, adopting a strict system like BEM, but as an application evolves, the class names become these monstrous, brittle strings, something like app-user-overview__status--is-authenticating. It’s not just long; it’s a maintenance nightmare. If you change the HTML structure, you’re suddenly forced into a cascade of class name revisions. It couples your styles so tightly to a specific markup that it loses all flexibility.
The @scope rule completely flips this dynamic. Instead of relying on class names to create boundaries, you use the rule itself. Imagine a simple button. With BEM, your HTML might look like . Your CSS is then littered with .button__text and other specific classes. With @scope, your HTML can be a much cleaner . In your CSS, you just write @scope (.primary-button) { span:first-child { /* styles */ } }. You’ve immediately eliminated the need for those extra button__text classes, simplifying your markup and letting you write selectors based on the actual document structure. It brings the focus back to CSS’s strengths instead of working around its perceived weaknesses.
Developers often adopt utility-first frameworks or CSS-in-JS for style isolation, but this can add build complexity and make debugging harder. In what ways does @scope provide a native, browser-based solution to style leakage without these trade-offs? Please share your experience.
I absolutely understand the appeal of those tools. When you’re fighting style leaks and specificity wars, the promise of complete isolation feels like a breath of fresh air. But it’s a deal with the devil. You trade CSS’s cascade for heavy build configurations and styles that are awkwardly intertwined with your component logic. I’ve seen projects where debugging a simple style issue requires navigating a labyrinth of autogenerated class names like .jsx-3130221066. You can’t just use the browser’s native developer tools effectively because the class you see in the inspector has no meaningful connection to the code you wrote. You’re debugging the tool, not your application.
This is where @scope is such a game-changer. It gives you that same powerful style isolation, but it’s a native browser feature. There’s no extra build step, no JavaScript overhead, and no unreadable class names. You’re just writing standard CSS. You can open the developer tools, inspect an element, and see the @scope rule applied directly. It respects the long-standing principle of separating concerns while still preventing styles from bleeding out and affecting unintended areas. It feels like we’re finally getting the tools to manage the cascade, not just run away from it.
The concept of “donut scoping” with a lower boundary is a powerful feature. Can you describe a real-world scenario where you would use @scope (nav) to (ul)? Explain how this is more maintainable than older methods like using complex :not selectors or manually resetting styles.
“Donut scoping” is a fantastic term for it, and it solves a classic UI problem. A perfect real-world example is a primary site navigation bar. Let’s say you have a
element, and you want all the tags directly inside it to have a specific style—say, bold and with extra padding. However, within that navigation, you have a dropdown menu, which is structured as a containing its own links. You don’t want those dropdown links to inherit the primary navigation’s styling.
The old way to handle this was messy. You’d either write a highly specific selector like nav > a that could easily break if the HTML structure changed, or you’d write a broad style for nav a and then a second, ugly override rule like nav ul a { font-weight: normal; padding: 0; } to reset the styles. It’s fragile and creates a lot of CSS bloat. With @scope (nav) to (ul), the intent is crystal clear. You’re telling the browser, “Apply these link styles within the
, but stop as soon as you hit a .” It’s declarative, concise, and far more robust against future markup changes.
With @scope, when two selectors have equal specificity, the rule whose scope root is closer to the element wins. How does this new proximity-based resolution change the way we handle overrides? Please share an anecdote where this would have solved a tricky specificity issue.
This new proximity rule is one of the most exciting aspects of @scope because it aligns CSS behavior with our mental model of how components should work. I can think of so many situations where this would have saved hours of debugging. There was one project with a generic .sidebar component that had a style for .title. Later, we built a more specific card component, let’s call it .container, that could be placed inside the sidebar. This .container also had its own .title style.
Because both selectors had the same specificity, we ran into a classic specificity war. To make the .container‘s title style apply, we had to write an ugly, high-specificity override like .sidebar .container .title { ... }. It felt wrong and made the CSS harder to reason about. With @scope, this problem just disappears. You’d have one scope for .sidebar and another for .container. When the title element is inside the .container, the .container scope is simply closer to it in the DOM tree. Its style wins automatically, no specificity hacks required. It’s a much more intuitive and natural way to handle component-based styling.
Web components often involve slotted content that inherits styles from the parent document. How can @scope be used to apply distinct styles to the same component, like a , depending on where it’s placed, such as within a versus a ?
This is a fantastic use case, especially as web components become more common in enterprise applications. The challenge with slotted content is that it lives in a sort of limbo—it’s part of the component’s Shadow DOM but is still influenced by the parent document’s styles. @scope gives you precise control over this. Imagine you have a reusable component. In a , you might want it to be a large, prominent block. But when you place that exact same inside a , you might want a more compact, inline style with a circular avatar.
Instead of adding modifier classes to the for each context, you can simply use @scope. You’d write a rule like @scope (team-roster) { user-card { display: inline-flex; } user-card img { border-radius: 50%; } }. The styles are applied based on the parent container, not on the component itself. This makes the component truly agnostic of its context. It’s a cleaner, more modular approach that keeps the styling logic where it belongs—with the container that dictates the layout, not the component being contained.
Beyond basic scoping, the rule can be combined with other modern CSS features. Could you walk through a practical use case that involves nesting scopes or using selectors like :has() and :scope to create highly specific styling boundaries without adding any classes?
The real power emerges when you start composing these modern features. Let’s say we’re styling a complex article layout within a
element. We want a base font size for all paragraphs. But inside a
, we want a slightly smaller font. Then, within that section, if a paragraph is inside a .highlight div, it needs a yellow background.
Without adding a single extra class to the paragraphs, you can achieve this with nested scopes: @scope (main) { p { font-size: 16px; } @scope (section) { p { font-size: 14px; } @scope (.highlight) { p { background-color: yellow; } } } } It’s incredibly readable. Now, let’s add :scope and :has() to the mix. Say we want to style paragraphs only within sections that are direct children of
, but we want to exclude any
elements inside those sections. The rule would be @scope (main > section) to (:scope > aside). Here, :scope elegantly refers back to the main > section root, creating a clean lower boundary. This level of precision, without touching the HTML, was simply not possible before. It allows for a surgical application of styles that feels both powerful and maintainable.
What is your forecast for the future of CSS architecture now that @scope and Cascade Layers are becoming widely available?
I believe we’re on the cusp of a major simplification in CSS architecture. For years, we’ve been compensating for the perceived shortcomings of the cascade with heavy tooling, complex naming conventions, and JavaScript-based solutions. Features like Cascade Layers and @scope are bringing the power back to CSS itself. Cascade Layers give us broad, architectural control over specificity, allowing us to define the “layers” of our application—like base styles, layouts, components, and utilities—and ensure they interact predictably. Then, @scope provides the fine-grained, component-level control to prevent style leaks without abandoning the cascade.
My forecast is that we’ll see a move away from the “all or nothing” approaches of utility-first frameworks in large-scale applications. Instead, we’ll see a hybrid, more intentional architecture where developers use Cascade Layers to manage the global styling context and then use @scope to build truly encapsulated, robust components. This combination gives us the best of both worlds: a predictable global system and safe, isolated components, all using native, browser-optimized CSS. It’s going to make writing maintainable CSS for complex applications easier and, frankly, a lot more fun.
