How could I resize input-group? - css

Question

I'm creating a jumbotron and trying to put an input-group form to make searches on my website. The problem is when I add the form with input and button and try to resize the form to 100% it doesn't stick together and the input text doesn't resize.
How could I fix this problem ?
trying
<div class="jumbotron">
<div class="row">
<div class="col-md-4">
<div class="img-responsive" style="margin:-50px 0 -20px 20px;">
<img src="~/Imagens/logo.png" />
</div>
</div>
<div class="col-md-4">
#using (Html.BeginForm("view", "Home", FormMethod.Post, new { role = "form" })){
#Html.AntiForgeryToken()
#Html.ValidationSummary(true)
<div class="input-group">
<input type="text" class="form-control" placeholder="What do you looking for ?">
<div class="input-group-btn">
<button class="btn glyphicon glyphicon-search"></button>
</div>
</div>
}
</div>
<div class="col-md-4">
#Html.Partial("_LoginPartial")
</div>
</div>
</div><!--jumbotron-->

Answer 1

You have some custom CSS on your page?
maybe this code can be the problem..
take a look:
<div class="jumbotron">
<div class="row">
<div class="col-md-4">
<form>
<div class="input-group">
<input type="text" class="form-control" placeholder="What do you looking for ?">
<div class="input-group-btn">
<button class="btn glyphicon glyphicon-search"></button>
</div>
</div>
</form>
</div>
</div>
https://jsfiddle.net/AlvaroAlves/0jrkhuy0/

Answer 2

Your Bootstrap code works fine, check this pen.
<div class="input-group">
<input type="text" class="form-control" placeholder="What do you looking for ?">
<div class="input-group-btn">
<button class="btn glyphicon glyphicon-search"></button>
</div>
</div>
Most probably some CSS code is interfering with Bootstrap's CSS.