iotaCSS is now a monorepo and all individual repositories are part of it. Please open issues or PRs here: https://github.com/iotacss/iotacss.
The size utility contains a set of classes for setting width in elements or grid columns. The sizes created are based on the Settings.Column.
npm install --save iotacss-utils-size
$iota-utils-size-namespace : '' !default;
$iota-utils-size-columns : $iota-global-columns !default;
$iota-utils-size-delimiter : \/ !default;
$iota-utils-size-res : false !default;
$iota-utils-size-breakpoints : $iota-global-breakpoints !default;
.u-[column-number]/[total-column-number] // Example .u-1/3
// Responsive Class Syntax
.u-[column-number]/[total-column-number]@[breakpoint-name] // Example: .u-1/3@sm