From the Semantic directory you can setup gulp to build Semantic by running.

npm install

Semantic will automatically configure itself using a post-install script built into the package.

After set-up can use gulp to build your project's css:

/* Watch files */
gulp watch

/* Build all files */
gulp build

Visit the Getting Started Guide for more details on set-up

Each gulp task can be imported into your own Gulpfile using require

var
  watch = require('path/to/semantic/tasks/watch')
;
gulp.task('watch ui', 'Watch Semantic UI', watch));

LESS files do not contain vendor prefixes. If you are to use these files directly you must add them during your build step.

Before using source files you will need to create a theme.config by renaming theme.config.example, and a site folder by renaming _site/ to site/

You can then import Semantic from your own LESS files:

/* Import all components */
@import 'src/semantic';

To import individual components you will have to create a scope for each import using & {}

/* Import a specific component */
& { @import 'src/definitions/elements/button'; }

These files are generated automatically using install scripts, but must be manually renamed if you are using installing manually.

You will only need to use Semantic's build tools while refining your UI. When designing pages, you can rely on the compiled css packages in dist/.

When creating your UI you can try downloading different themes, adjusting your site-wide settings (font-family, colors, etc) and tweaking components in your site's component overrides.

Files in the examples/ folder of your project can be useful for testing out changes in your UI. For example, you might run gulp watch download a new theme to src/site/themes/ then adjust your theme.config file with the name of the new theme and refresh examples/kitchensink.html to inspect changes in the theme.

There are three levels of inheritance in Semantic

• Default theme - Semantic UI's neutral default theme
• Packaged theme - A specified packaged theme, like "amazon", or "material"
• Site theme - A theme specific to your site

• definitions/ contains the css and javascript definitions for each component
• themes/ contains pre-packaged themes including Semantic's default theme
• site/ contains your current site's theme

View the Theming Guide for a more in-depth look

The best way to start customizing is to specify overriding variables in your site's site.variables file.

This is a blank stub file that lets you specify variables that overriding variables.

Some important values to customize:

• Base font size
• Named color hex codes
• Header/Page Font-families
• Primary and secondary colors
• Grid column count

To find out what variables are available to modify, you can inspect the variables in the default theme in themes/default/

Each component has its own variable file, which can be used to modify any of the underlying variables for that component.

For example /site/elements/button.variables.

You may also specify your own custom LESS in site/elements/button.overrides. This file will have access to all underlying variables available for that component.

You can modify theme.config to use any prepackaged theme available in src/themes/.

For example you can modify theme.config to use a github button theme by changing

@button: 'github';

View the Customization Guide to learn more