This image shows breakpoints (in pixels) which shows when does CSS takes affect. Example:
Usage | Breakpoint name | Screen width Style is applied |
Mobile | lt-lg | up to 599px (including) |
Tablet portrait | sm | starting from 600px |
Tablet portrait | lt-md | up to 899px (including) |
Tablet landscape | md | starting from 900px |
Tablet landscape | lt-lg | up to 1199px (including) |
Desktop | lg | starting from 1200px |
Desktop | lt-xl | up to 1799px (including) |
Large desktop | xl | starting from 1800px |