Some missing styles!

[EhssanD]

bootstrap provides some styles for .clearfix class. It seems that you have missed it.

https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css

[EhssanD]

Here is the original code

.btn-group-vertical>.btn-group:after,
.btn-group-vertical>.btn-group:before,
.btn-toolbar:after,
.btn-toolbar:before,
.clearfix:after,
.clearfix:before,
.container-fluid:after,
.container-fluid:before,
.container:after,
.container:before,
.dl-horizontal dd:after,
.dl-horizontal dd:before,
.form-horizontal .form-group:after,
.form-horizontal .form-group:before,
.modal-footer:after,
.modal-footer:before,
.modal-header:after,
.modal-header:before,
.nav:after,
.nav:before,
.navbar-collapse:after,
.navbar-collapse:before,
.navbar-header:after,
.navbar-header:before,
.navbar:after,
.navbar:before,
.pager:after,
.pager:before,
.panel-body:after,
.panel-body:before,
.row:after,
.row:before{
    display:table;content:" "
}
.btn-group-vertical>.btn-group:after,
.btn-toolbar:after,
.clearfix:after,
.container-fluid:after,
.container:after,
.dl-horizontal dd:after,
.form-horizontal .form-group:after,
.modal-footer:after,
.modal-header:after,
.nav:after,
.navbar-collapse:after,
.navbar-header:after,
.navbar:after,
.pager:after,
.panel-body:after,
.row:after{
    clear:both
}

[EhssanD]

Also you have missed these lines too,

* {
    -webkit-box-sizing: border-box;
    -moz-box-sizing: border-box;
    box-sizing: border-box;
}
*:before, *:after {
    -webkit-box-sizing: border-box;
    -moz-box-sizing: border-box;
    box-sizing: border-box;
}

This is why #115 happens!