Responsive it is.
Just a simple package that turn your selected pixels text into rem.
The px-to-rem package can be installed through Atom. Alternatively, you can use apm:
apm install px-to-rem
Normally px is converted to rem using a base value of 16, but you set this value in the settings page.
By default the number of decimal places are limited by Atom. If you want to change this behavior, you can set the number of desired decimal places that will be displayed when converting int the settings page.
1 - Select the part of the code you want to change, for example '40px;'. And then, type Ctrl+Shift+E (Cmd+Shift+E for Mac users).
2 - Or you can select a block of text. And then, type Ctrl+Shift+E (Cmd+Shift+E for Mac users).
Feel free to fork this repository and use it the way you like. If you want to propose a nice new feature, just create a pull request from you forked branch.