How to create square around glyphicon bootstrap?

Question

I want to create an icon like this:

<link href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css" rel="stylesheet"/>
<span class="glyphicon glyphicon-plus" aria-hidden="true"></span>

How to draw a square around this icon? Thanks.

Updated: seem add CSS my code is broken.

You can see it like:

All not show correct.

Updated code:

span.glyphicon {
    background-color: #eee;
    border: 1px solid #000;
    border-radius: 8px;
    height: 50px !important;
    padding-top: 17px;
    text-align: center;
    width: 50px !important;
}

<link href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css" rel="stylesheet"/>
<div class="panel-group" id="accordion" role="tablist" aria-multiselectable="true">
  <div class="panel panel-primary">
    <div class="panel-heading active" role="tab" id="headingOne">
      <h4 class="panel-title">
        <a class="collapsed" role="button" data-toggle="collapse" data-parent="#accordion" href="#collapseOne" aria-expanded="true" aria-controls="collapseThree">
          Example <span class="glyphicon glyphicon-plus pull-right" aria-hidden="true"></span>
        </a>
      </h4>
    </div>
    <div id="collapseOne" class="panel-collapse collapse in" role="tabpanel" aria-labelledby="headingOne" aria-expanded="true">
      <div class="panel-body">
        <div class="list-group">

          <form accept-charset="UTF-8" action="" method="post">

            <select name="select_baogia" class="select_baogia">
              <option value="">Tree 1</option>
              <option value="">Tree 2</option>
              option
            </select>
            <input  name="name" placeholder="Name" type="text"> 
            <input  name="email" placeholder="Email" type="text">
            <input class="text_baogia"  name="phone" placeholder="Phone num" type="text"> 
            <input name="diadiem" placeholder="Location" type="text"> 
            <button class="btn btn-warning" type="submit">Call back to me</button>
          </form>


        </div>
      </div>
    </div>
  </div>

Answer 1

1. You can do with CSS:

span.glyphicon.glyphicon-plus {
  background-color: #eee;
  border: 1px solid #000;
  border-radius: 8px;
  height: 50px !important;
  padding-top: 17px;
  text-align: center;
  width: 50px !important;
}

<link href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css" rel="stylesheet"/>

<span class="glyphicon glyphicon-plus" aria-hidden="true"></span>

2. You can do as a button:

<link href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css" rel="stylesheet"/>

<a class="btn btn-default" href="#" role="button"><span class="glyphicon glyphicon-plus" aria-hidden="true"></span></a> or 
<button class="btn btn-default" type="submit"><span class="glyphicon glyphicon-plus" aria-hidden="true"></span></button>

Look the doc: http://getbootstrap.com/css/#buttons

Update

span.glyphicon.glyphicon-plus {
    background-color: #eee;
    border: 1px solid #888;
    border-radius: 8px;
    height: 30px !important;
    margin-top: -8px;
    padding-top: 6px;
    text-align: center;
    width: 30px !important;
}

<link href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css" rel="stylesheet"/>
<div class="panel-group" id="accordion" role="tablist" aria-multiselectable="true">
  <div class="panel panel-primary">
    <div class="panel-heading active" role="tab" id="headingOne">
      <h4 class="panel-title">
        <a class="collapsed" role="button" data-toggle="collapse" data-parent="#accordion" href="#collapseOne" aria-expanded="true" aria-controls="collapseThree">
          Example <span class="glyphicon glyphicon-plus pull-right" aria-hidden="true"></span>
        </a>
      </h4>
    </div>
    <div id="collapseOne" class="panel-collapse collapse in" role="tabpanel" aria-labelledby="headingOne" aria-expanded="true">
      <div class="panel-body">
        <div class="list-group">
          <form accept-charset="UTF-8" action="" method="post">
            <select name="select_baogia" class="select_baogia">
              <option value="">Tree 1</option>
              <option value="">Tree 2</option>
            </select>
            <input  name="name" placeholder="Name" type="text"> 
            <input  name="email" placeholder="Email" type="text">
            <input class="text_baogia"  name="phone" placeholder="Phone num" type="text"> 
            <input name="diadiem" placeholder="Location" type="text"> 
            <button class="btn btn-warning" type="submit">Call back to me</button>
          </form>
        </div>
      </div>
    </div>
  </div>

Note: CSS is a very simple language. You can learn with w3school: http://www.w3schools.com/css/default.asp

Answer 2

You can put this in the css, this would answer your question.

.glyphicon{
border:1px solid #000;
padding: 5px 10px;
}

EDIT

Here is a working js fiddle

https://jsfiddle.net/px3h7kz9/