Problem about bootstrap carousel resizing

I am trying to resize a bootstarp 4 carousel. But after I done that. There are some white background left.

I've tried making the background transparent, none. margin, border, padding to 0. box-shadow to none.

Nothing helps.

But if I add class "carousel-caption" aside of "carousel" or "float: left;" the white background will be gone.

I wish to know if there is any other methods to fix this problem. And what is causing it.

Codepen: https://codepen.io/kudratullah/pen/bmdNjp (The Codepen isn't belongs to me, but it shares the same problem of mine.)

If you turned all the background colors to black, you can still sees the left/right side of the carousel will be still in white background.

Screen Shot: Codepen

My codes are at below:

HTML:

<div id="demo" class="carousel slide slider-horizontal" data-ride="carousel">
    <ul class="carousel-indicators">
        <li data-target="#demo" data-slide-to="0" class="active"></li>
        <li data-target="#demo" data-slide-to="1" class="active"></li>
        <li data-target="#demo" data-slide-to="2" class="active"></li>
    </ul>

    <div class="carousel-inner">
        <div class="carousel-item active">
            <img src="Picture.jpg">
        </div>
        <div class="carousel-item">
            <img src="Picture.jpg">
        </div>
        <div class="carousel-item">
            <img src="Picture.jpg">
        </div>
    </div>

        <a class="carousel-control-prev" href="#demo" data-slide="prev">
            <span class="carousel-control-prev-icon"></span>
        </a>
        <a class="carousel-control-next" href="#demo" data-slide="next">
            <span class="carousel-control-next-icon"></span>
        </a>
</div>

CSS:

.slider-horizontal
{
    width: 60%;
    margin: auto;
}
.carousel-inner img
{
    width: 100%;
}

Many Thanks!!

Solution

Please use additional container class and change background to black.Here's the solution:

body
{
    background: black!important;
}

.container{
background:black;
}

.slider-horizontal
{
    width: 60%;
    margin: auto;
   
}
.carousel-inner img
{
    width: 100%;
}

<head>
    <link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.4.1/css/bootstrap.min.css">

    <script src="https://code.jquery.com/jquery-3.4.1.js"></script>
    <script src="https://cdn.jsdelivr.net/npm/[email protected]/dist/umd/popper.min.js"></script>
    <script src="https://stackpath.bootstrapcdn.com/bootstrap/4.4.1/js/bootstrap.min.js"></script>
</head>

<body>
<div class="container">
<div id="demo" class="carousel slide slider-horizontal" data-ride="carousel">
    <ul class="carousel-indicators">
        <li data-target="#demo" data-slide-to="0" class="active"></li>
        <li data-target="#demo" data-slide-to="1" class="active"></li>
        <li data-target="#demo" data-slide-to="2" class="active"></li>
    </ul>

    <div class="carousel-inner">
        <div class="carousel-item active">
            <img src="https://image.shutterstock.com/image-photo/lovely-beach-picture-beautiful-260nw-1554809048.jpg">
        </div>
        <div class="carousel-item">
            <img src="https://image.shutterstock.com/image-photo/lovely-beach-picture-beautiful-260nw-1554809048.jpg">
        </div>
        <div class="carousel-item">
            <img src="https://image.shutterstock.com/image-photo/lovely-beach-picture-beautiful-260nw-1554809048.jpg">
        </div>
    </div>

        <a class="carousel-control-prev" href="#demo" data-slide="prev">
            <span class="carousel-control-prev-icon"></span>
        </a>
        <a class="carousel-control-next" href="#demo" data-slide="next">
            <span class="carousel-control-next-icon"></span>
        </a>
</div>
</body>

If you want something else, please let me know.