CSS writing-mode is a brand new property that defines whether text is laid out horizontally or vertically, and the direction in which blocks progress.
CSS Writing Mode was created to solve a growing problem: displaying multiple types of languages properly in your websites in a fast and easy way. For example, English is displayed/read from left to right. Arabic is read from right to left.
The default value of writing-mode is horizontal-tb. This is used in horizontal languages like English. In all cases, the content flows vertically from top to bottom. Other values include:
horizontal-tb
Makes the content flow horizontally from left to right.
vertical-rl
Makes the content flow horizontally from right to left.
vertical-lr
Makes the content flow horizontally from left to right.
sideways-rl
Makes all the content flow sideways towards the right.
sideways-lr
Makes all the content flow sideways towards the left.
Support for CSS Writing-mode is very limited.
Currently only supported fully by Mozilla Firefox, you will have to use -webkit- tag to make it work in any webkit browsers. No browser other than Firefox supports the sideways-rl or sideways-lr values.