<hr> tag in Twitter Bootstrap not functioning correctly?

Here is my code:

<div class="container">
<div>
<h1>Welcome TeamName1</h1>
  asdf
  <hr>
  asdf

</div>
</div> <!-- /container -->

The hr tag does not seem to work as I would expect it. Instead of drawing a line, it creates a gap, like so:

the css property of <hr> are :

hr {
  -moz-border-bottom-colors: none;
  -moz-border-image: none;
  -moz-border-left-colors: none;
  -moz-border-right-colors: none;
  -moz-border-top-colors: none;
  border-color: #EEEEEE -moz-use-text-color #FFFFFF;
  border-style: solid none;
  border-width: 1px 0;
  margin: 18px 0;
}

It correspond to a 1px horizontal line with a very light grey and vertical margin of 18px.

and because <hr> is inside a <div> without class the width depends on the content of the <div>

if you would like the <hr> to be full width, replace <div> with <div class='row'><div class='span12'> (with according closing tags).

If you expect something different, describe what you expect by adding a comment.

Instead of writing

<hr>

Write

<hr class="col-xs-12">

And it will display full width as normal.

I solved this by setting the HR background-color to black like so:

<hr style="width: 100%; color: black; height: 1px; background-color:black;" />

It is because Bootstrap's DEFAULT CSS for <hr /> is ::

hr {
    margin-top: 20px;
    margin-bottom: 20px;
    border: 0;
    border-top: 1px solid #eeeeee;
}

it creates 40px gap between those two lines

so if you want to change any particular <hr /> margin style in your page you may try something like this ::

<hr style="margin-bottom:5px !important; margin-top:5px !important; " />

if you want to change appearance/other styles of any particular <hr /> in your page like color and border type or thickness the you may try something like :

<hr style="border-top: 1px dotted #000000 !important; " />

for all <hr /> in your page

<style>
   hr {
       border-top: 1px dotted #000000 !important;
       margin-bottom:5px !important; 
       margin-top:5px !important;
   }
</style>

By default, the hr element in Twitter Bootstrap CSS file has a top and bottom margin of 18px. That's what creates a gap. If you want the gap to be smaller you'll need to adjust margin property of the hr element.

In your example, do something like this:

.container hr {
margin: 2px 0;
}