Bootstrap/less/grid.less

//
// Grid system
// --------------------------------------------------


// Set the container width, and override it for fixed navbars in media queries
.container {
  .container-fixed();
}

// Mobile-first defaults
.row {
  margin-left:  @grid-gutter-width / -2;
  margin-right: @grid-gutter-width / -2;
  .clear_float();
}
[class^="span"] {
  min-height: 1px;
  padding-left:  @grid-gutter-width / 2;
  padding-right: @grid-gutter-width / 2;
  // Proper box-model (padding doesn't add to width)
  -webkit-box-sizing: border-box;
     -moz-box-sizing: border-box;
          box-sizing: border-box;
}

// Responsive: Tablets and up
@media screen and (min-width: 768px) {
  .container {
    max-width: 728px;
  }
  // Generate the grid columns and offsets
  [class^="span"] {
    float: left;
  }
  #grid > .core(@grid-column-width, @grid-gutter-width);
}

// Responsive: Desktops and up
@media screen and (min-width: 992px) {
  .container {
    max-width: 940px;
  }
}

// Responsive: Large desktops and up
@media screen and (min-width: 1200px) {
  .container {
    max-width: 1170px;
  }
  [class^="span"] {
    padding-left: 15px;
    padding-right: 15px;
  }
}

// Reset utility classes due to specificity
[class*="span"].pull-right {
  float: right;
}