Magento2 less

magento2less.md

npm install -g grunt-cli

project/magento2/dev/tools/grunt/configs/themes.js

mytheme: {
    area: 'frontend',
    name: 'YourProject/Theme',
    locale: 'en_US',
    files: [ 'your/theme/CSS' ],
    dsl: 'less'
},

blank: {
    area: 'frontend',
    name: 'Magento/blank',
    locale: 'en_US',
    files: [
        'css/styles-m',
        'css/styles-l',
        'css/email',
        'css/email-inline'
    ],
    dsl: 'less'
},
luma: {
    area: 'frontend',
    name: 'Magento/luma',
    locale: 'en_US',
    files: [
        'css/styles-m',
        'css/styles-l'
    ],
    dsl: 'less'
},
backend: {
    area: 'adminhtml',
    name: 'Magento/backend',
    locale: 'en_US',
    files: [
        'css/styles-old',
        'css/styles'
    ],
    dsl: 'less'
}

grunt exec:[theme] Cleans the static directory of existing assets and recreates them based on the current file system.

This command is essential. If ever you add new LESS files, Grunt won’t actually be able to know about them until you re-run this command so that it pulls LESS files from your theme folder into the pub/static directory.

grunt less[:your-theme] Compiles the LESS files that Grunt finds in the pub/static directory from the entry points defined in your your-project/magento2/dev/tools/grunt/configs/themes.js directory.

grunt watch Watches your pub/static directory for changes in files (which are replicated over the symlinks to your theme directory), then recompiles the LESS files.