cssファイル使わずにjavascriptのみで簡単にスタイルをあてる。 ref: http://qiita.com/coa00@github/items/29c6d2b65f1ec19529da

file0.css

    .hoge {
        background-color: #fff;
    }

    .hoge:hover {
        border: 1px solid #0097cf;
    }

file0.txt

hoge.css
fuga.js
test.js

file1.js

    var css = '<style type="text/css">\
    .hoge {\
        background-color: #fff;\
    }\
    .hoge:hover {\
        border: 1px solid #0097cf;\
    }\
    </style>';
   $(body).append($('css'));

file1.txt

all.js

file2.css

    .hoge {
        background-color: #fff;
    }

    .hoge:hover {
        border: 1px solid #0097cf;
    }

file2.js

gulp.task('templates', function(){
    var src = "./src/css/";
    var dest = src+'templates/build';//出力場所
    gulp.src(src+'/*.css')
        .pipe(handlebars())
        .pipe(wrap('Handlebars.template(<%= contents %>)'))
        .pipe(declare({
            namespace: 'App.css',
            noRedeclare: true // Avoid duplicate declarations
        }))
        .pipe(concat('style.js'))
        .pipe(gulp.dest(dest));
});

file3.js

    var css = '<style type="text/css">\
    .hoge {\
        background-color: #fff;\
    }\
    .hoge:hover {\
        border: 1px solid #0097cf;\
    }\
    </style>';
   $(body).append($('css'));

file3.txt

        $("body").append(App.css.style);

file4.txt

        $("body").append(App.css.style);

file5.js

gulp.task('templates', function(){
    var src = "./src/css/";
    var dest = src+'templates/build';//出力場所
    gulp.src(src+'/*.css')
        .pipe(handlebars())
        .pipe(wrap('Handlebars.template(<%= contents %>)'))
        .pipe(declare({
            namespace: 'App.css',
            noRedeclare: true // Avoid duplicate declarations
        }))
        .pipe(concat('style.js'))
        .pipe(gulp.dest(dest));
});

file6.txt

        $("body").append(App.css.style);

style.css

<style type="text/css">
    .hoge {
        background-color: #fff;
    }

    .hoge:hover {
        border: 1px solid #0097cf;
    }
</style>