Arbitrary arguments
Use explicit points, colors, transforms, and animation timing.
Use Tailwind's bracket notation to supply values outside the theme scale.
Text("Room for ideas")
.tw("text-[22] tracking-[0.3] p-[24] w-[360] rounded-[22] bg-[#6366f1] text-[#fff]")
.tw("hover:scale-[1.02] animate-smooth duration-[220ms]")Supported values
| Classes | Arguments |
|---|---|
w-[240], h-[80], size-[44] | Width, height, or both dimensions |
min-w-[80], max-w-[300], min-h-[44], max-h-[200] | Native size limits |
p-[13], px-[12], py-[8], pt-[4], pb-[4], ps-[4], pe-[4] | Padding in native points |
rounded-[14], border-[1.5] | Corner radius or border width |
text-[18], text-[length:18px] | Fixed native font size in points |
text-[#fff], bg-[#6366f1], border-[color:#6366f180] | Hex colors in RGB or RGBA order |
text-[color:brand], bg-[brand], border-[color:brand] | Registered adaptive theme colors |
opacity-[0.8] | Native opacity from zero to one |
tracking-[0.5], tracking-[-0.5] | Character tracking on a native Text value |
line-spacing-[4] | Native gap between text lines in points |
line-clamp-[2], line-clamp-2, line-clamp-none | Native line limit or removal of the inherited limit |
text-start, text-center, text-end | Native multiline text alignment |
offset-[12,-4] | Horizontal and vertical offsets in points |
scale-[1.05], scale-[1.1,0.9] | Uniform or separate horizontal and vertical scale factors |
rotate-[3deg], rotate-[0.05rad] | Rotation in degrees or radians |
blur-[2] | Native blur radius in points |
duration-[400], duration-[400ms], duration-[0.4s], delay-[75ms] | Animation timing |
Units and typography
Bare bracket lengths use native points. The pt and px suffixes also represent native points.
For example, w-12 follows the theme scale; w-[48] always uses 48 points.
Bare bracket timing values use milliseconds. Bare rotation values use degrees.
Size tokens such as text-lg retain scalable SwiftUI font roles.
Explicit font sizes such as text-[18] use a fixed native font size.
Native line spacing controls the gap between lines; CSS line height needs a separate mapping.
Apply tracking directly to Text, before modifiers that wrap it in another view.
Other views keep their normal rendering and log a diagnostic for an unsupported tracking target.
Unspecified text attributes preserve native inheritance.
Parsing and validation
State variants, group variants, named classes, and local overrides also accept bracket values.
Colons inside brackets belong to the argument. Underscores represent spaces; \_ preserves a literal underscore.
Use comma-separated scalar values for offset and scale arguments.
Numeric helpers reject invalid numbers, unsupported units, and nonfinite values.
Percentages, rem, calc, and CSS variables have no native mappings and fail validation.
Try the class editor
The native Arguments demo accepts a live class string. It shows unsupported classes and invalid values beside the preview.
Extend the vocabulary with custom utility factories.
Use native modifier plugins when a registered class should produce a real SwiftUI modifier.