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HTML

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Insecure Resource

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CSS

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CSS preprocessors help make authoring CSS easier. All of them offer things like variables and mixins to provide convenient abstractions.

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CSS Base

About CSS Base

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JavaScript

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JavaScript preprocessors can help make authoring JavaScript easier and more convenient.

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Babel includes JSX processing.

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HTML 

              
                <div class="wrapper">
	<h1>Tips for keeping fish</h1>
	<ul>
		<li>The bigger the tank or aquarium the better. Most fish may be small in size, but they still need plenty of room to swim, especially if you have decided to get more than one.</li>
		<li>Think about where you place your tank. Keep it out of direct sunlight, away from windows and heating. The last thing you want is for the water in the tank to heat up out of your control.</li>
		<li>Invest in a decent filter. This will keep the water in the tank cleaner for longer, removing any debris, pollutants and waste.</li>
		<li>Add an air pump. This will keep the water in the tank oxygenated and keep it moving which is great for your fish. Pumps come in different sizes depending on the amount of litres your tank can hold.</li>
	</ul>
</div>
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CSS 

              
                * {
	box-sizing: border-box;
}

body {
	font-family: "Open Sans", sans-serif;
	margin: 0;
	padding: 1rem;
}

.wrapper {
	max-width: 600px;
	margin: 0 auto;
}

ul {
	list-style: none;
	padding: 0;
}

li + li {
	margin-top: 1rem;
}

li {
	display: flex;
	align-items: center;
	gap: 1rem;
	background: aliceblue;
	padding: 1.5rem;
	border-radius: 1rem;
	width: calc(100% - 2rem);
	box-shadow: 0.25rem 0.25rem 0.75rem rgb(0 0 0 / 0.1);
}

li::before {
	content: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 576 512' width='100' title='fish'%3E%3Cpath d='M327.1 96c-89.97 0-168.54 54.77-212.27 101.63L27.5 131.58c-12.13-9.18-30.24.6-27.14 14.66L24.54 256 .35 365.77c-3.1 14.06 15.01 23.83 27.14 14.66l87.33-66.05C158.55 361.23 237.13 416 327.1 416 464.56 416 576 288 576 256S464.56 96 327.1 96zm87.43 184c-13.25 0-24-10.75-24-24 0-13.26 10.75-24 24-24 13.26 0 24 10.74 24 24 0 13.25-10.75 24-24 24z' /%3E%3C/svg%3E");
}

li:nth-child(even) {
	flex-direction: row-reverse;
	background: honeydew;
	margin-right: -2rem;
	margin-left: 2rem;
}

li:nth-child(even)::before {
	transform: rotateY(180deg);
}
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JS
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999px

Console