Can't use Bulma.css responsiveness

are you compiling it with elixir / gulp?

Yes, any idea?

That just looks like regular css, not Bulma.css. Don't you just use their library in your html elements, not write the css yourself?

@jlrdw I'm just trying to use bulma's responsiveness mixins but i can't. Search on google did not found.

+mobile, +tablet etc ...

Considering Bulma is mobile first you should set your CSS as mobile then set none mobile CSS. In other words your CSS is backwards. But disclaimer ive never used bulma.

http://bulma.io/documentation/overview/responsiveness/

@selmonal you are compiling it with elixir/gulp, but in a scss or sass file?

as far as I know:

.post-title
  text-align: left

  +mobile
    text-align: center

is sass syntax and will only work if you rename your app.scss to app.sass (also in your gulp file). I haven't tested your code but it should help and the css output of your code should be something like:

.post-title {
  text-align: left;
}
@media screen and (max-width: 768px) {
  .post-title {
    text-align: center;
  }
}

You want to use

@include tablet {
    //some styles here
}