When I open for editing, the CSS of the bootstrap.min is a tab without a tab.
Can you solve this?
I would like to make a simple edit in the source of a class and even identifying the line by the browser inspection, it is still difficult to find inside the .css.
Marcelo, bootstrap.min means that it is the mini-bootstrap. Minimizing a file means reducing its size as much as possible. In this case, all possible spaces and possible joys of the file have been eliminated in order to reduce their vertical size and thus reduce the size of the original file. This allows the browser to load the bootstrap file faster.
To download the original non-mined file, you can access the official bootstrap website: link .
This version of CSS that you are viewing is a 'minification' of the original source (note the '-min' in the file name), so it looks like a "massaroca" ...
You should use a CSS formatter, or rather: look for the non-minimized version.
In the download options , you can choose to download the source code and modify them according to your needs.
If you need to modify a single class, it may be simpler to use !important in the properties which is altering:
button:last-of-type {
color: #fff !important;
background-color: #333 !important;
border: none !important;
}<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.5/css/bootstrap.min.css">
<button class='btn btn-default'>padrão</button>
<button class='btn btn-default'>customizado</button>