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HTML

              
                <closable-surface demo>
	<h2>Hello world with a longer title. Check this out, the text will wrap below the close icon.</h2>
	<p>In this example, the content of this surface will not collide with the close button when the surface is resized or content is changed. There is a floating element which causes text to wrap around the corner where the button appears. Then the button is positioned in the corner based on the parent's reference.</p>
	<p>You can remove the <code>demo</code> attribute from the <code>closable-surface</code> element to see the final effect without the blue visualized floating box.</p>
</closable-surface>
              
            
!

CSS

              
                body {
	font-family: sans-serif;
}

closable-surface {
	border: 1px solid black;
	border-radius: .5em;
}

h2 {
	margin: 0;
	font-size: 2em;
}

code {
	background: #eee;
	padding: 0 2px;
}
              
            
!

JS

              
                const html = `
<style type="text/css">
	:host {
		display: block;
		position: relative;
		overflow: hidden;
		max-width: 500px;
		margin: 0 auto;
		--padding: 1rem;
		--button-size: 2em;
		padding: var(--padding);
	}
	
	span.floater {
		float: right;
		display: block;
		width: calc(var(--button-size) - var(--padding));
		height: calc(var(--button-size) - var(--padding));
		font-size: 1.5em;
	}
	
	:host([demo]) span.floater {
		background: rgba(0,0,255, .3);
	}
	
	button {
		position: absolute;
		top: 0;
		right: 0;
		background: rgba(240, 240, 240, 0);
		font: inherit;
		border: 0;
		cursor: pointer;
		display: inline-flex;
		align-items: center;
		justify-content: center;
		aspect-ratio: 1/1;
		width: var(--button-size);
		transition: .218s ease;
	}
	
	button:hover {
		background: rgba(240, 240, 240, .8);
	}
</style>
<div>
	<span class="floater">
		<button>×</button>
	</span>
	<slot></slot>
</div>
`

class ClosableSurface extends HTMLElement {
	constructor() {
		super();
		this.attachShadow({ mode: 'open'}).innerHTML = html;
	}
}

window.customElements.define('closable-surface', ClosableSurface);
              
            
!
999px

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