How to achieve a particular width using col-mds in bootstrap 3.0? -

i'm using bootstrap 3.0 , provides widths in terms of col-md-value(value-1-12).i have design page using it.the total page width 1000px , divided 2 sections of width 280 , 720 respectively.

to achieve 1000px have changed max-width of 'container' 1000px achieve 280px if use col-md-3 gives 25% width in terms of pixels 250px ans if use col-md-4 give 300 somethng

so question here how achieve these 2 widths using col-mds because if make our own custom style achieve bootstrap not provide responsive nature? mark looks hown below:

   <div class="container"><---1000px max-width-->      <div class="col-md-12"> <--100% width--->         <div class="col-md-value">           </div>         <div class="col-md-value">          </div>       </div>     </div> 

you can add custom css using media queries

e.g

@media screen , (min-width:1000px){ .col-md-value{ width: ---; }  .col-md-value{ width: ---; } } 

this style apply screens having more 1000px display width; , bootstrap work other resolutions.use approximate values col-md.