gruntjs - grunt-autoprefixer and grunt-postcss not working -

i have tried both plugins grunt-autoprefixer , grunt-postcss neither adding prefixes. have tried caniuse.com says requires prefix (cursor: grab).

here autoprefixer task:

   autoprefixer: {         dev: {             no_dest: {                 src: 'dev/styles.css'             }         },         live: {             no_dest: {                 src: 'live/styles.css'             }         }     } 

and here postcss task:

   postcss: {         dev: {             options: {                 processors: [                     require('autoprefixer-core')({browsers: 'last 1 version'}).postcss                 ]             },             dist: {                 src: 'dev/styles.css'             }         }     } 

could give try following grunt packages

• grunt-postcss
• autoprefixer-core

and following snippet

postcss: {   options: {     processors: [       require('autoprefixer-core')({browsers: 'last 1 version'}).postcss     ]   },   single_file: {     src: 'src/main.css',     dest: 'css/main.css'   },   multiple_files: [{     expand: true,     flatten: true,     src: 'src/css/*.css', // -> src/css/file1.css, src/css/file2.css     dest: 'dest/css/' // -> dest/css/file1.css, dest/css/file2.css   }] }