Sass 3.4.20 发布，更新如下：
Fix a bug with the rounding changes from 3.4.14 and 3.4.15 where some negative numbers would incorrectly be rounded up instead of down.
Better compression for :nth pseudoselectors with subtraction.Issue #1650
Add support for the new supports() clause for CSS @import directives.
Rounding numbers now respects Sass's precision setting for numbers very close to half an integer.
Add support for the q unit, representing one quarter of a millimeter.
Mitigate a race condition when multiple threads are using the sameSass::Plugin object at once.
In compressed mode, numbers between -1 and 1 now have the leading 0 omitted.
Source maps now include source ranges for comments.
Sass 扩展了 CSS3，增加了规则、变量、混入、选择器、继承等等特性。Sass 生成良好格式化的 CSS 代码，易于组织和维护。
软件详情：https://github.com/sass/sass/blob/9077d95ffa6ab9388f59074483f1ef508d75d448/doc-src/SASS_CHANGELOG.md
下载地址：https://github.com/sass/sass/tree/3.4.20
来自:开源中国社区
