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HTML

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HTML preprocessors can make writing HTML more powerful or convenient. For instance, Markdown is designed to be easier to write and read for text documents and you could write a loop in Pug.

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CSS

About CSS Preprocessors

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

It's a common practice to apply CSS to a page that styles elements such that they are consistent across all browsers. We offer two of the most popular choices: normalize.css and a reset. Or, choose Neither and nothing will be applied.

Vendor Prefixing

About Vendor Prefixing

To get the best cross-browser support, it is a common practice to apply vendor prefixes to CSS properties and values that require them to work. For instance -webkit- or -moz-.

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JavaScript

About JavaScript Preprocessors

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

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Babel includes JSX processing.

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HTML 

              
                - var h = 2000, w = 2*h;
- var x = -.5*w, y = -h;
- var r = .225*h;
- var nr = 16, a = Math.PI/nr;
- var asw = a*r;
- var sw = .004*h, fs = Math.round(.075*h);
- var na = Math.round(.05*fs);
- var rm = 2*r + fs;
- var x0 = Math.round(rm*Math.sin(a));
- var y0 = Math.round(rm*Math.cos(a));
- var x1 = Math.round(rm*Math.sin(2*a));
- var y1 = Math.round(rm*Math.cos(2*a));
- var x2 = Math.round(rm*Math.sin(4*a));
- var y2 = Math.round(rm*Math.cos(4*a));
- var x3 = Math.round(rm*Math.sin(6*a));
- var y3 = Math.round(rm*Math.cos(6*a));

svg(viewBox=[x, y, w, 1.5*h].join(' ') 
		xmlns='http://www.w3.org/2000/svg')
	style
		| * {
		| 	fill: #333;
		| 	font: #{Math.round(.84*fs)}px consolas, monaco, monospace
		| }
		| tspan { fill: #f90 }
		| #a { fill: #b53 }
		| #b { fill: #95a }
		| [d], [r] {
		| 	fill: none;
		| 	stroke: #333;
		| 	stroke-width: #{sw}
		| }
		| [x] + [d] { stroke: #ccc }
		| [r] {
		| 	stroke-width: #{2*r};
		| 	stroke-dasharray: #{asw.toFixed(2)}
		| }
		| [r] ~ [x] { fill: #ccc }
		| [r] + * * { font: #{Math.round(.84*fs)}px comic sans ms, cursive }
		| [r] ~ [d] { stroke: #f90; stroke-width: #{1.5*sw} }
		| #m { stroke: #b53 }
		| #n { stroke: #95a }
	text(x=x + .2*fs y=.75*y + fs) repeating-conic-gradient(#000 <tspan>0%</tspan> <tspan id='a'>$p/2</tspan>, transparent <tspan>0%</tspan> <tspan id='b'>$p</tspan>)
	text(x=(x + .2*fs) y=y + 3*fs) $p: 100%/$nr
	path(d=`M${x2}${-y2}L0 0L${x3}${-y3}`)
	path(d=`M0${-rm}V0L${x0}${-y0}M0 0L${x1}${-y1}`)
	circle(r=r)
	text(x=-1.3*fs y=y + fs)
		tspan ray start
		tspan#a(dy=fs) ray end
		tspan(dy=-fs) gap start
		tspan#b(dy=fs) gap end
	path(d=`M0${-rm}l${.7*fs}${-2*fs}m${.2*fs}${-.7*fs}l${-.4*fs}${-2.5*fs}m${7.5*fs} 0l${2.5*fs} ${2.5*fs}`)
	path#m(d=`M${x0}${-y0}l${1.5*fs}${-1.9*fs}m${.5*fs}${-.9*fs}l${.8*fs}${-1.5*fs}`)
	path#n(d=`M${x1}${-y1}l${.8*fs - x - x2}${-2.5*fs}m${.2*fs}${-.7*fs}l${-.5*fs}${-1.5*fs}`)
	text(x=x2 - 2*fs y=-(y2 + .6*fs)) repeat
	text(x=x3 - 1.2*fs y=-(y3 + fs)) repeat
	text(x=(x + .2*fs) y=y + 2*fs) // $nr: number of rays

// minimal SVG
<svg viewBox='-2000 -2000 4000 3000' xmlns='http://www.w3.org/2000/svg'><style>*{fill:#333;font:126px consolas,monaco,monospace}tspan{fill:#f90}#a{fill:#b53}#b{fill:#95a}[d],[r]{fill:none;stroke:#333;stroke-width:8}[x]+[d]{stroke:#ccc}[r]{stroke-width:900;stroke-dasharray:88.36}[r]~[x]{fill:#ccc}[r]+* *{font:126px comic sans ms,cursive}[r]~[d]{stroke:#f90;stroke-width:12}#m{stroke:#b53}#n{stroke:#95a}</style><text x='-1970' y='-1350'>repeating-conic-gradient(#000 <tspan>0%</tspan> <tspan id='a'>$p/2</tspan>, transparent <tspan>0%</tspan> <tspan id='b'>$p</tspan>)</text><text x='-1970' y='-1550'>$p: 100%/$nr</text><path d='M742-742L0 0L970-402'/><path d='M0-1050V0L205-1030M0 0L402-970'/><circle r='450'/><text x='-195' y='-1850'><tspan>ray start</tspan> <tspan id='a' dy='150'>ray end</tspan> <tspan dy='-150'>gap start</tspan> <tspan id='b' dy='150'>gap end</tspan></text><path d='M0-1050l105-300m30-105l-60-375m1125 0l375 375'/><path id='m' d='M205-1030l225-285m75-135l120-225'/><path id='n' d='M402-970l1378-375m30-105l-75-225'/><text x='442' y='-832'>repeat</text><text x='790' y='-552'>repeat</text><text x='-1970' y='-1700'>// $nr: number of rays</text></svg>
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CSS 

              
                body {
	display: flex;
	flex-direction: column;
	margin: 0;
	height: 100vh;
}
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JS
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999px

Console