swift-css

Typed CSS for Swift HTML rendering — inline style methods, dark-mode color pairs, and named themes that emit light and dark CSS custom properties.

---

Key Features

• Grouped property methods — .css.frame(...), .css.spacing(...), .css.text(...), and .css.flexContainer(...) set related CSS properties in a single call and render as HTML inline styles.
• Dark-mode colors — DarkModeColor stores light and dark values as one normalized pair, auto-deriving the dark variant when only a light color is supplied.
• Named themes — DarkModeColor.Theme ships palettes mirroring familiar systems (.github, .apple, .vapor, .slate, and more), each exposing semantic text, background, border, and branding color roles.
• Stylesheet generation — theme.stylesheet emits CSS custom properties for every role, paired with a @media (prefers-color-scheme: dark) override block and matching utility classes.
• Scoped theming — prepareDependencies sets process-wide theme and font defaults; withDependencies overrides them for a single synchronous or asynchronous operation.

---

Quick Start

A single named theme value expands into a complete stylesheet — every semantic color as a CSS custom property, plus a @media (prefers-color-scheme: dark) block carrying the dark variants:

import CSS_Theming

let stylesheet = DarkModeColor.Theme.github.stylesheet

print(stylesheet)
// /* Generated Theme Stylesheet */
// :root {
//     --color-blue: ...;
//     --text-primary: ...;
// }
// @media (prefers-color-scheme: dark) {
//     :root { --color-blue: ...; }
// }

DarkModeColor.Theme.StyleSheet conforms to CustomStringConvertible, so it interpolates into any output directly.

---

Installation

dependencies: [
    .package(url: "https://github.com/swift-foundations/swift-css.git", branch: "main")
]

.target(
    name: "YourTarget",
    dependencies: [
        .product(name: "CSS", package: "swift-css")
    ]
)

Requires Swift 6.3.1 and macOS 26 / iOS 26 / tvOS 26 / watchOS 26 / visionOS 26.

---

Architecture

Three library products. CSS Theming and CSS Test Support re-export CSS.

Product	Import	When to import
CSS	import CSS	Inline CSS property methods and the dark-mode color types.
CSS Theming	import CSS_Theming	Named themes, stylesheet generation, and scoped theming defaults; re-exports CSS.
CSS Test Support	import CSS_Test_Support	Test targets that snapshot rendered CSS; re-exports both library targets.

---

Community

Discussion thread will be created at first public release.

License

Apache 2.0. See LICENSE.