<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8" />
<title>宽高比</title>
<base href="/" />
<link rel="icon" type="image/png" href="favicon.png" />
<link rel="stylesheet" href="bootstrap/css/bootstrap.min.css" />
<link rel="stylesheet" href="css/app.css" />
<script src="/plugs/holder/holder.min.js"></script>
<style>
.bd-example-ratios .ratio {
display: inline-block;
width: 10rem;
color: var(--bs-secondary-color);
background-color: var(--bs-tertiary-bg);
border: var(--bs-border-width) solid var(--bs-border-color)
}
.bd-example-ratios .ratio>div {
display: flex;
align-items: center;
justify-content: center
}
</style>
</head>
<body>
<div class="container">
<div class="card mt-3">
<div class="card-header .bg-dark-subtle">
<strong>宽高比: </strong> 使用生成的伪元素使元素保持您选择的纵横比。非常适合根据父项的宽度响应式处理视频或幻灯片嵌入。
</div>
<div class="card-body">
<h4>将父元素中的任何嵌入（如 ）包装为纵横比类。由于我们的通用选择器，直接子元素会自动调整大小。.ratio .ratio-21x9</h4>
<div class="ratio ratio-21x9">
<iframe src="http://www.ifiredoor.com" title="上海防火门" allowfullscreen></iframe>
</div>
</div>
</div>
<div class="card mt-3">
<div class="card-header .bg-dark-subtle">
<strong>纵横比: </strong> 纵横比可以使用修饰符类进行自定义。默认情况下，提供以下比率类：
</div>
<div class="card-body bd-example-ratios">
<div class="ratio ratio-1x1">
<div class="border border-2 bg-body-secondary">1x1</div>
</div>
<div class="ratio ratio-4x3">
<div class="border border-2 bg-body-secondary">4x3</div>
</div>
<div class="ratio ratio-16x9">
<div>16x9</div>
</div>
<div class="ratio ratio-21x9">
<div>21x9</div>
</div>
</div>
</div>
<div class="card mt-3">
<div class="card-header .bg-dark-subtle">
<strong>自定义比例: </strong>
</div>
<div class="card-body bd-example-ratios">
<div class="ratio" style="--bs-aspect-ratio: 50%;">
<div>2x1</div>
</div>
</div>
</div>
</div>
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</body>
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