I'm having trouble with Bootstrap 3 creating an internal stylesheet in the head region with some very odd looking classes. I've included the first few classes in the code block below, but there are about 275 lines with classes for lg, md, sm & xs, all with odd numbers.
What's going on?

<style type="text/css">
.btn1 {  display: none;
}
.btn1 {  display: inline;
  margin-left: .3em;
  zoom: 1;
  white-space: nowrap;
}
.col-lg-13 {  position: relative;
  min-height: 1px;
  padding-left: 2%;
  padding-right: 2%;
}
.col-lg-101 {  position: relative;
  min-height: 1px;
  padding-left: 2%;
  padding-right: 2%;
}
.col-lg-111 {  position: relative;
  min-height: 1px;
  padding-left: 2%;
  padding-right: 2%;
}
.col-lg-121 {  position: relative;
  min-height: 1px;
  padding-left: 2%;
  padding-right: 2%;
}
.col-lg-21 {  position: relative;
  min-height: 1px;
  padding-left: 2%;
  padding-right: 2%;
}
.col-lg-31 {  position: relative;
  min-height: 1px;
  padding-left: 2%;
  padding-right: 2%;
}
.col-lg-41 {  position: relative;
  min-height: 1px;
  padding-left: 2%;
  padding-right: 2%;
}
.col-lg-51 {  position: relative;
  min-height: 1px;
  padding-left: 2%;
  padding-right: 2%;
}
.col-lg-61 {  position: relative;
  min-height: 1px;
  padding-left: 2%;
  padding-right: 2%;
}
.col-lg-71 {  position: relative;
  min-height: 1px;
  padding-left: 2%;
  padding-right: 2%;
}
.col-lg-81 {  position: relative;
  min-height: 1px;
  padding-left: 2%;
  padding-right: 2%;
}
.col-lg-91 {  position: relative;
  min-height: 1px;
  padding-left: 2%;
  padding-right: 2%;
}
.col-md-13 {  position: relative;
  min-height: 1px;
  padding-left: 2%;
  padding-right: 2%;
}
.col-md-13 {    float: left;
}
.col-md-101 {  position: relative;
  min-height: 1px;
  padding-left: 2%;
  padding-right: 2%;
}
.col-md-101 {    float: left;
}
.col-md-111 {  position: relative;
  min-height: 1px;
  padding-left: 2%;
  padding-right: 2%;
}
.col-md-111 {    float: left;
}
.
.
.

Hello David,
Please explain the steps to reproduce this? You can safely remove all of these lines, as they shouldn't be there.

Thanks for getting back to me so quickly Teodor!
I think it may be something to do with copying & pasting code when I should not have.

Some of the cell classes refer to this:
<div class="col-md-41">

I think I'll start over and check carefully every step of the way.

Dave

The bootstrap classes for cells cannot be more than col-xxx-12, so everything larger than 12 is wrong. Just delete them and recreate the layout again.