<div class="filebox">
						  <label for="ex_file">업로드</label> 
						  <input type="file" id="ex_file"> 
						</div>

<div class="filebox bs3-primary">
						  <label for="ex_file2">업로드</label> 
						  <input type="file" id="ex_file2"> 
						</div>

<div class="filebox bs3-success">
						  <label for="ex_file2">업로드</label> 
						  <input type="file" id="ex_file2"> 
						</div>

<a href="http://webdir.tistory.com/435" target="_blank" class="where">posted in webdir</a> 

body {margin: 10px}
.where {
  display: block;
  margin: 25px 15px;
  font-size: 11px;
  color: #000;
  text-decoration: none;
  font-family: verdana;
  font-style: italic;
} 
.filebox {display:inline-block; margin-right: 10px;}


.filebox label {
  display: inline-block;
  padding: .5em .75em;
  color: #999;
  font-size: inherit;
  line-height: normal;
  vertical-align: middle;
  background-color: #fdfdfd;
  cursor: pointer;
  border: 1px solid #ebebeb;
  border-bottom-color: #e2e2e2;
  border-radius: .25em;
}

.filebox input[type="file"] {  /* 파일 필드 숨기기 */
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip:rect(0,0,0,0);
  border: 0;
}

.filebox.bs3-primary label {
  color: #fff;
  background-color: #337ab7;
	border-color: #2e6da4;
}

.filebox.bs3-success label {
  color: #fff;
  background-color: #5cb85c;
	border-color: #4cae4c;
}