Technology — CSS3
Layouts that hold up at every viewport.
Modern CSS — Grid, container queries, custom properties — building UIs that adapt without breaking.
What does responsive CSS actually have to handle?
Modern CSS at S3A Technologies means treating stylesheets with the same engineering rigour as application code — design tokens as custom properties, fluid type scales, container queries and theme switching, with no drive-by overrides and no global important declarations. Deliverables include design tokens for colour, spacing and type consumed everywhere and hard-coded nowhere; a fluid type scale that adapts to viewport without a stack of breakpoints; a layout system using Grid at page level and container queries inside components, so a component responds to its own box rather than the window; theming covering light, dark and brand variants driven from a single token layer; scoped component styles with no leaking selectors; and written naming conventions. We work System, Layout, Components, Polish — with reduced-motion, dark mode and print stylesheets handled before launch rather than retrofitted.
What this is
CSS as engineering.
Design tokens, fluid type scales, container queries and theme switching — treated with the same rigour as the rest of the codebase. No drive-by overrides, no global !important.
What you get
In the stylesheet.
Design tokens
Colour, spacing and type as custom properties — consumed everywhere, hard-coded nowhere.
Fluid type scale
Typography that scales with the viewport without a stack of breakpoints.
Layout system
Grid and container queries, so components respond to their box rather than the window.
Theming
Light, dark and brand variants driven from a single token layer.
Component styles
Scoped, predictable rules with no global overrides and no !important.
Conventions
Naming and usage notes, so the system survives the next contributor.
How we do it
System, layout, components, polish.
- 01
System
Tokens for colour, type and space defined as custom properties from the start.
- 02
Layout
Grid and Flexbox at the page level, container queries inside each component.
- 03
Components
Encapsulated styles per component — no leaking selectors, no specificity wars.
- 04
Polish
Reduced-motion, dark mode and print stylesheets handled before launch.
Proof
Where this shipped.
Layouts that had to hold from a 360px Android to a desk monitor — a B2B catalog and a hospitality site.
Kunal Enterprises
A B2B multi-brand catalog covering 7 product categories and 4 customer segments, built mobile-first so a buyer goes from browsing to a one-tap WhatsApp enquiry.
→ 4.2× revenue YoYPazzellaa Villa, Alibag
Brand, website, Google presence, social and 9 OTA channels built from zero, then run as one programme — 78% annual occupancy and 35% of bookings direct at zero commission.
→