Скруглил углы изображения на 20px, почему - то появился контур. Попробовал с помощью border: 0; убрать не помогло. Кто - нибуть может знает в чем может быть проблема ?
<!doctype html>
<html lang="ru">
<head>
<!-- Required meta tags -->
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no">
<!-- Bootstrap CSS -->
<link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.4.1/css/bootstrap.min.css" integrity="sha384-Vkoo8x4CGsO3+Hhxv8T/Q5PaXtkKtu6ug5TOeNV6gBiFeWPGFN9MuhOf23Q9Ifjh" crossorigin="anonymous">
<!-- fonts -->
<link href="https://fonts.googleapis.com/css2?family=Barlow:wght@600&display=swap" rel="stylesheet">
<!-- style.css -->
<link rel="stylesheet" href="css/style.css">
<title>Tea</title>
</head>
<body>
<!-- header -->
<header>
<div class="container-fluid shadow p-2 mb-4 bg-white rounded">
<nav class="navbar navbar-expand-lg navbar-light">
<a class="navbar-brand" href="#">Logo</a>
<button class="navbar-toggler" type="button" data-toggle="collapse" data-target="#navbarSupportedContent" aria-controls="navbarSupportedContent" aria-expanded="false" aria-label="Toggle navigation">
<span class="navbar-toggler-icon"></span>
</button>
<div class="collapse navbar-collapse" id="navbarSupportedContent">
<ul class="navbar-nav mr-auto">
<li class="nav-item dropdown active">
<a class="nav-link dropdown-toggle" href="#" id="navbarDropdown" role="button" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
Каталог товаров
</a>
<div class="dropdown-menu" aria-labelledby="navbarDropdown">
<a class="dropdown-item" href="#">Зеленый чай</a>
<a class="dropdown-item" href="#">Черный чай</a>
<div class="dropdown-divider"></div>
<a class="dropdown-item" href="#">Кедропласт</a>
</div>
</li>
<li class="nav-item">
<a class="nav-link" href="#">Доставка</a>
</li>
<li class="nav-item">
<a class="nav-link" href="#">Оплата</a>
</li>
<li class="nav-item">
<a class="nav-link" href="#">О нас</a>
</li>
<li class="nav-item">
<a class="nav-link" href="#">Контакты</a>
</li>
</ul>
<form class="form-inline my-2 my-lg-0">
<input class="form-control mr-sm-2" type="search" placeholder="Поиск по названию" aria-label="Search">
<button class="btn btn-outline-success my-2 my-sm-0" type="submit">Найти</button>
</form>
</div>
</nav>
</div>
</header>
<!-- slider -->
<div class="container slider">
<div id="slider" class="carousel slide carousel-fade" data-ride="carousel">
<ol class="carousel-indicators">
<li data-target="#slider" data-slide-to="0" class="active"></li>
<li data-target="#slider" data-slide-to="1"></li>
</ol>
<div class="carousel-inner">
<div class="carousel-item active ">
<img class=" card-item" src="img/header-tea-1.jpg" class="d-block w-100" alt="tea1">
</div>
<div class="carousel-item">
<img class=" card-item" src="img/header-tea-2.jpg" class="d-block w-100" alt="tea2">
</div>
</div>
<a class="carousel-control-prev" href="#slider" role="button" data-slide="prev">
<span class="carousel-control-prev-icon" aria-hidden="true"></span>
<span class="sr-only">Previous</span>
</a>
<a class="carousel-control-next" href="#slider" role="button" data-slide="next">
<span class="carousel-control-next-icon" aria-hidden="true"></span>
<span class="sr-only">Next</span>
</a>
</div>
</div>
<!-- grid item -->
<!-- в этом участке проблема -->
<div class="grid-posts">
<div class="container">
<div class="row">
<div class="col-md-3">
<div class="card">
<img class="card-img-top card-item" src="img/card-1.jpg">
</div>
</div>
<div class="col-md-3">
<div class="card">
<img class="card-img-top card-item" src="img/card-2.jpg">
</div>
</div>
<div class="col-md-3">
<div class="card">
<img class="card-img-top card-item" src="img/card-2.jpg">
</div>
</div>
<div class="col-md-3">
<div class="card">
<img class="card-img-top card-item" src="img/card-2.jpg">
</div>
</div>
</div>
</div>
</div>
<!-- в этом участке проблема -->
<!-- Optional JavaScript -->
<!-- jQuery first, then Popper.js, then Bootstrap JS -->
<script src="https://code.jquery.com/jquery-3.4.1.slim.min.js" integrity="sha384-J6qa4849blE2+poT4WnyKhv5vZF5SrPo0iEjwBvKU7imGFAV0wwj1yYfoRSJoZ+n" crossorigin="anonymous"></script>
<script src="https://cdn.jsdelivr.net/npm/popper.js@1.16.0/dist/umd/popper.min.js" integrity="sha384-Q6E9RHvbIyZFJoft+2mJbHaEWldlvI9IOYy5n3zV9zzTtmI3UksdQRVvoxMfooAo" crossorigin="anonymous"></script>
<script src="https://stackpath.bootstrapcdn.com/bootstrap/4.4.1/js/bootstrap.min.js" integrity="sha384-wfSDF2E50Y2D1uUdj0O3uMBJnjuUD4Ih7YwaYd1iqfktj0Uod8GCExl3Og8ifwB6" crossorigin="anonymous"></script>
</body>
</html>
body{
min-width: 320px;
font-size: 14px;
font-family: 'Barlow', sans-serif;
color: #626262;
}
img{
max-width: 100%;
height: auto;
}
a{
color: #b4ad9e;
}
a:hover{
color: #898377;
}
.slider{
margin-top: 15px;
}
header .nav-item{
text-transform: uppercase;
margin-left: 10px;
}
.card-item{
border-radius: 20px;
}
