Why do my Twitter Bootstrap form fields overflow their well using fluid container?

Question

UPDATE: Demo of problem here: http://jsfiddle.net/fdB5Q/embedded/result/

From about 767px to 998px, the form fields are wider than the containing well.

Smaller t

Answer 1

As indicated by Pavlo in this answer: Twitter Bootstrap: Stop input field extending beyond well

Using the class input-block-levelin place of the input-xlarge (or other sizes) solves the problem as well.

Answer 2

For anyone to find

Html:

<input class="form-control" placeholder="Threshold Type">

CSS:

.form-control { box-sizing: border-box; }