Container Queries
Container queries allow you to apply styles based on the size of a container rather than the viewport.
CSS Subgrid
Subgrid extends CSS Grid to allow nested grids to participate in the parent grid's layout.
CSS Cascade Layers
Cascade layers provide explicit control over the cascade, making it easier to manage competing styles.
New Color Functions
Modern CSS includes new color functions like color-mix() and relative color syntax.
Logical Properties
Logical properties provide international-friendly alternatives to physical properties.