CSS if(): Inline Conditionals for Smarter Styling

Originally published on danholloran.me There's a moment every CSS developer knows: you want to tweak a single property based on some condition — a viewport width, a user preference, a custom property — and instead of a clean one-liner you end up with a whole new @media block, duplicated selectors, and maybe a dash of JavaScript to handle the edge cases. It works, but it never feels right. The CSS if() function changes that. Shipping in Chrome 137, it brings inline conditional logic directly into your property declarations, letting you express branching style logic without leaving the property itself. How if() Works The syntax is a sequence of condition-value pairs, evaluated top to bottom until one matches: property : if ( condition : value ; else : fallback ); The function supports three types of conditions: style() — queries computed CSS custom property values media() — runs an inline media query supports() — feature-detects a CSS property or syntax You can chain them with else : button { padding : if ( media ( width >= 1024px ): 0.5rem 1.5rem ; else : 0.75rem 1.25rem ); } That's a responsive padding rule with zero extra @media blocks. Three Practical Uses 1. Touch-Friendly Targets with media() The pointer media feature lets you distinguish mouse users from touchscreen users. The accessible minimum tap target is 44px; mouse users can get away with smaller: .icon-button { width : if ( media ( any-pointer : fine ): 32px ; else : 44px ); height : if ( media ( any-pointer : fine ): 32px ; else : 44px ); } Previously this needed a full @media (any-pointer: coarse) block. Now it reads like what it is — a single property with two states. 2. Theme Switching with style() Custom properties are often used to carry design tokens — theme flags, component variants, status values. The style() query lets you branch on them inline: .status-badge { --status : pending ; background : if ( style ( --status : complete ): #22c55e ; style( --status : error ): #ef4444 ; else : #f59e0b );