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About CSS Preprocessors
CSS preprocessors help make authoring CSS easier. All of them offer things like variables and mixins to provide convenient abstractions.
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.
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-.
We offer two popular choices: Autoprefixer (which processes your CSS server-side) and -prefix-free (which applies prefixes via a script, client-side).
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Open the console in CodePen or in your browser's Developer Tools.
// Two values in scientific notation, one returns Infinity
let bigNumber = 1e308,
biggerNumber = 1e309;
console.log(bigNumber); // 1e+308
console.log(biggerNumber); // Infinity
// A more precise representation of where Infinity is returned
let largeNumber = 1.7976931348623157e+308,
largerNumber = 1.7976931348623157e+309;
console.log(largeNumber); // 1.7976931348623157e+308
console.log(largerNumber); // Infinity