paulirish

What forces layout / reflow

All of the below properties or methods, when requested/called in JavaScript, will trigger the browser to synchronously calculate the style and layout*. This is also called reflow or layout thrashing, and is common performance bottleneck.

Generally, all APIs that synchronously provide layout metrics will trigger forced reflow / layout. Read on for additional cases and details.

Element APIs

Getting box metrics

• elem.offsetLeft, elem.offsetTop, elem.offsetWidth, elem.offsetHeight, elem.offsetParent

chriseppstein

Sass/Less Comparison

In this document I am using Sass's SCSS syntax. You can choose to use the indented syntax in sass, if you prefer it, it has no functional differences from the SCSS syntax.

For Less, I'm using the JavaScript version because this is what they suggest on the website. The ruby version may be different.

Variables