png white background html

I remove the background in the picture to transparent. I save the image in png format, but when displayed on the page, a white background still appears in places where the background was not there. What's the matter? using bootstrap 3 enter a description of the image here

        <div id="headerwrap" id="home" name="home">
        <header class="clearfix">
                <h1>
                    <a class="center-block" href="#home"><img src="assets/img/btn.png"></a>
                </h1>
        </header>       
        </div>
        .center-block {
            display: block;
            margin-right: auto;
            margin-left: auto;
        }

enter a description of the image here

 2
Author: Антон Бурак, 2017-03-14

1 answers

All right:

.center-block {
  display: block;
  margin-right: auto;
  margin-left: auto;
}

#headerwrap {
  background: #000;
  
  text-align: center;
}
<div id="headerwrap" name="home">
  <header class="clearfix">
    <h1>
      <a class="center-block" href="#home">
        <img src="https://i.stack.imgur.com/njxtw.png">
      </a>
    </h1>
  </header>       
</div>

Perhaps the link somewhere by default still has styles set and a white background set, or the image itself has a background set.

By the way, <div id="headerwrap" id="home" name="home"> can only have one id

 5
Author: HamSter, 2017-03-14 07:12:12