Estou tentando importarbootstrap.css dentro de.less , para que eu possa aplicar condicionalmente os estilos do Bootstrap com consultas de mídia.

Aqui está o meu código MENOS:

// Visual Studio is saying "Couldn't locate" the file for both, yet they are there:
@import url("bootstrap.min.css");
@import url("bootstrap-theme.min.css");

// ...can't find the source of the "@screen" at-rules:
@extra-small: ~"screen and (max-width: @screen-xs-max)";
@small:       ~"screen and (min-width: @screen-sm-min) and (max-width: @screen-sm-max)";
@medium:      ~"screen and (min-width: @screen-md-min) and (max-width: @screen-md-max)";
@large:       ~"screen and (min-width: @screen-lg-min)";

footer {
    text-align: center;

    // ...doesn't like the comma "or" syntax here, so "or" is used instead:
    @media @extra-small or @small {
        #linkedin-flair {
            .hide // compile error
        }
        #stackoverflow-flair {
            .hide // compile error
        }
    }

    @media @medium {
        #linkedin-flair {
            .col-sm-3 // compile error
        }
        #copyright-text {
            .col-sm-6 // compile error
        }
        #stackoverflow-flair {
            .col-sm-3 // compile error
        }
    }

    @media @large {
        #linkedin-flair {
            .col-sm-4 // compile error
        }
        #copyright-text {
            .col-sm-4 // compile error
        }
        #stackoverflow-flair {
            .col-sm-4 // compile error
        }
    }
}

... o MENOS está tendo problemas com o@import e@screen at-rules e com referência a quaisquer classes de Bootstrap, como.hide.

Estou usando o Visual Studio 2013, o Web Essentials 2013 e o Bootstrap 3.